Installation Instructions - Air conditioning · or use can cause explosion, fire, electrical shock,...

1

50XT---AInfinityt 15 SEER Single---Packaged Heat PumpSystem With Puron® (R---410A) RefrigerantSingle Phase2 to 5 Nominal Tons (Sizes 24---60)

Installation Instructions

EQUIPMENT OPERATION HAZARD

OAT sensor must be field installed. See AccessoryInstallation for more details.

! CAUTION


This Infinity unit is designed for use with an Infinity UserInterface.

! CAUTION

NOTE: Read the entire instruction manual before starting theinstallation.

TABLE OF CONTENTSPAGE

SAFETY CONSIDERATIONS 2. . . . . . . . . . . . . . . . . . . . . . . . .INTRODUCTION 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .RECEIVING AND INSTALLATION 2--12. . . . . . . . . . . . . . . . .Check Equipment 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Identify Unit 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Inspect Shipment 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Provide Unit Support 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Roof Curb 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Slab Mount 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Provide Clearances 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Rig and Place Unit 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Inspection 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Rigging/Lifting of Unit 6. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Select and Install Ductwork 7. . . . . . . . . . . . . . . . . . . . . . . . . . .Converting Horizontal Discharge Units to Downflow(Vertical) Discharge Units 8. . . . . . . . . . . . . . . . . . . . . . . . . .

Provide for Condensate Disposal 8. . . . . . . . . . . . . . . . . . . . . .Install Electrical Connections 9. . . . . . . . . . . . . . . . . . . . . . . . .High--Voltage Connections 9. . . . . . . . . . . . . . . . . . . . . . . . .Routing Power Leads Into Unit 9. . . . . . . . . . . . . . . . . . . . . .Connecting Ground Lead to Ground Screw 9. . . . . . . . . . . .Routing Control Power Wires 11. . . . . . . . . . . . . . . . . . . . .Accessory Installation 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .Special Procedures for 208--v Operation 12. . . . . . . . . . . . . .

PRE--START--UP 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .START--UP 13--20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Unit Start--Up 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sequence of Operation 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .Check for Refrigerant Leaks 20. . . . . . . . . . . . . . . . . . . . . . . . .Start--Up Adjustments 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Checking Cooling and Heating Control Operation 20. . . . . .Checking and Adjusting Refrigerant Charge 20. . . . . . . . . . .Refrigerant Charge 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A09032

Fig. 1 -- Unit 50XT

No Charge 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Low Charge Cooling 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . .To Use Cooling Charging Charts 20. . . . . . . . . . . . . . . . . . . .Indoor Airflow and Airflow Adjustments 20. . . . . . . . . . . . .

Non--Communicating Emergency Cooling/Heating Mode 20. .MAINTENANCE 22--24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Air Filter 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Indoor Fan and Motor 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Outdoor Coil, Indoor Coil, and Condensate Drain Pan 23. . . . .Outdoor Fan 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Electrical Controls and Wiring 23. . . . . . . . . . . . . . . . . . . . . . .Refrigerant Circuit 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Indoor Airflow 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Metering Devices–TXV & AccuRater® Piston 23. . . . . . . . . . .Pressure Switches 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Loss--of--Charge Switch 24. . . . . . . . . . . . . . . . . . . . . . . . . . . .High--Pressure Switches 24. . . . . . . . . . . . . . . . . . . . . . . . . . . .Copeland Scroll Compressor (Puron® Refrigerant) 24. . . . . . . .Refrigerant System 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Refrigerant 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Compressor Oil 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Servicing Systems on Roofs with Synthetic Materials 24. . . .Liquid--Line Filter Drier 24. . . . . . . . . . . . . . . . . . . . . . . . . .Puron (R--410A) Refrigerant Charging 24. . . . . . . . . . . . . . .

TROUBLESHOOTING 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .FINAL CHECKS 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CARE AND MAINTENANCE 26. . . . . . . . . . . . . . . . . . . . . . . .START--UP CHECKLIST 29. . . . . . . . . . . . . . . . . . . . . . . . . . . .

2

SAFETY CONSIDERATIONSImproper installation adjustment, alteration, service, maintenance,or use can cause explosion, fire, electrical shock, or otherconditions which may cause death, personal injury, or propertydamage. Consult a qualified installer, service agency, or yourdistributor or branch for information or assistance. The qualifiedinstaller or agency must use factory--authorized kits or accessorieswhen modifying this product Refer to the individual instructionspackaged with the kits or accessories when installing.Follow all safety codes. Wear safety glasses, protective clothing,and work gloves. Use quenching cloth for brazing operations.Have a fire extinguisher available. Read these instructionsthoroughly and follow all warnings or cautions included inliterature and attached to the unit. Consult local building codes, thecurrent editions of the National Electrical Code (NEC) NFPA 70.In Canada refer to the current editions of the Canadian electricalCode CSA C22.1.

Recognize safety information. This is the safety--alert symbol .When you see this symbol on the unit and in instructions ormanuals, be alert to the potential for personal injury. Understandthese signal words; DANGER, WARNING, and CAUTION. Thesewords are used with the safety--alert symbol. DANGER identifiesthe most serious hazards which will result in severe personal injuryor death. WARNING signifies hazards which could result inpersonal injury or death. CAUTION is used to identify unsafepractices which may result in minor personal injury or product andproperty damage. NOTE is used to highlight suggestions whichwill result in enhanced installation, reliability, or operation.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personalinjury or death.

Before installing or servicing system, always turn off mainpower and tag disconnect to system. There may be morethan one disconnect switch. Turn off accessory heater powerswitch if applicable.

! WARNING

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could result in personalinjury or equipment damage.

Puron (R--410A) systems operate at higher pressures thanstandard R--22 systems. DO NOT use R--22 serviceequipment or components on Puron (R--410A) equipment.Ensure service equipment is rated for Puron (R--410A).

WARNING!

CUT HAZARD

Failure to follow this caution may result in personal injury.

When removing access panels or performing maintenancefunctions inside your unit, be aware of sharp sheet metal partsand screws. Although special care is taken to reduce sharpedges to a minimum, be extremely careful when handlingparts or reaching into the unit.

! CAUTION

INTRODUCTIONThe 50XT--A packaged heat pump is fully self--contained anddesigned for outdoor installation (See Fig. 1). Standard units areshipped in a horizontal--discharge configuration for installation ona rooftop, or a cement slab (see Fig. 4 for roof curb details).Standard units can be converted to downflow (vertical) dischargeconfigurations for rooftop applications.

RECEIVING AND INSTALLATIONStep 1 — Check EquipmentIDENTIFY UNITThe unit model number and serial number are printed on the unitinformative plate. Check this information against shipping papers.INSPECT SHIPMENTInspect for shipping damage before removing packaging material.If unit appears to be damaged or is torn loose from its anchorage,have it examined by transportation inspectors before removal.Forward claim papers directly to transportation company.Manufacturer is not responsible for any damage incurred in transit.Check all items against shipping list. Immediately notify thenearest Carrier office if any item is missing. To prevent loss ordamage, leave all parts in original packages until installation.Step 2 — Provide Unit SupportIMPORTANT: The unit must be secured to the curb by installingscrews through the bottom of the curb flange and into the unit baserails. When installing large base units onto the common curb, thescrews must be installed before allowing the full weight of the unitto rest on the curb. A minimum of six screws are required for largebase units. Failure to secure unit properly could result in anunstable unit. See Warning near Rigging/Lifting information andaccessory curb instructions for more details.For hurricane tie downs, contact distributor for details and PE(Professional Engineering) Certificate, if required.ROOF CURBInstall accessory roof curb in accordance with instructions shippedwith curb (See Fig. 4). Install insulation, cant strips, roofing, andflashing. Ductwork must be attached to curb.IMPORTANT: The gasketing of the unit to the roof curb iscritical for a water tight seal. Install gasketing material suppliedwith the roof curb. Improperly applied gasketing also can result inair leaks and poor unit performance.Curb should be level to within 1/4 in. (6.4 mm) (See Fig. 2). Thisis necessary for unit drain to function properly. Refer to accessoryroof curb installation instructions for additional information asrequired.

A

B

C

MAXIMUM ALLOWABLEDIFFERENCE in. (mm)

A-C

1/4 1/4 1/4(6.35) (6.35) (6.35)

A-B B-C

A07925

Fig. 2 -- Unit Leveling TolerancesSLAB MOUNTPlace the unit on a solid, level concrete pad that is a minimum of 4in. thick with 2 in. (51 mm) above grade. The slab should extendapproximately 2 in. (51 mm) beyond the casing on all 4 sides ofthe unit (See Fig. 3). Do not secure the unit to the slab except whenrequired by local codes.

OPTIONALRETURN

AIROPENING

OPTIONALSUPPLY

AIROPENING

EVAP. COIL COND. COIL

2˝(50.8mm)

A07926

Fig. 3 -- Slab Mounting Detail

50XT--A

3

RETURN AIR

SMALLBASE UNIT

SUPPLYAIR

LARGEBASE UNIT

UNIT PLACEMENT ON COMMON CURB

C

B

A

F

D

E

LARGE CURB

C

B

A

F

DE

Dashed lines show cross supportlocation for large basepan units.

SMALL OR LARGE BASE UNIT

COMMON CURB

ROOF CURB DETAIL

Wood nailer*

Roofcurb*

Insulation(field supplied)

*Provided with roofcurb

Cant stripfield supplied

Roofing materialfield supplied

Flashing fieldsupplied

HVAC unitbase rails

Roofcurb

SealingGasket

HVAC unitbasepan

Anchor screw

A09090

A09095

A09096

A09094

A09097

UNIT SIZE CATALOGNUMBER

AIN. (mm)

B (small base)IN. (mm)*

B (large base)IN. (mm)*

CIN. (mm)

DIN. (mm)

EIN. (mm)

FIN. (mm)

Small orLarge

CPRFCURB010A00 11 (279)10 (254)

14 (356) 16 (406) 47.8 (1214)32.4 (822)

2.7 (69)CPRFCURB011A00 14 (356)

LargeCPRFCURB012A00 11 (279)

14 (356) 43.9 (1116)CPRFCURB013A00 14 (356)

NOTES:1. Roof curb must be set up for unit being installed.

2. Seal strip must be applied, as required, to unit being installed.

3. Roof curb is made of 16--gauge steel.

4. Attach ductwork to curb (flanges of duct rest on curb).

5. Insulated panels: 1--in. (25 mm) thick fiberglass 1 lb. density.

Fig. 4 -- Roof Curb Dimensions

50XT--A

4

A09128

Fig. 5 -- 50XT--A24--30 Unit Dimensions

50XT--A

5

A09129

Fig. 6 -- 50XT--A36--60 Unit Dimensions

50XT--A

6

Step 3 — Provide ClearancesThe required minimum service clearances are shown in Fig. 5 and6. Adequate ventilation and outdoor air must be provided. Theoutdoor fan draws air through the outdoor coil and discharges itthrough the top fan grille. Be sure that the fan discharge does notrecirculate to the outdoor coil. Do not locate the unit in either acorner or under an overhead obstruction. The minimum clearanceunder a partial overhang (such as a normal house overhang) is 48in. (1219 mm) above the unit top. The maximum horizontalextension of a partial overhang must not exceed 48 in. (1219 mm).IMPORTANT: Do not restrict outdoor airflow. An air restrictionat either the outdoor--air inlet or the fan discharge may bedetrimental to compressor life.Do not place the unit where water, ice, or snow from an overhangor roof will damage or flood the unit. Do not install the unit oncarpeting or other combustible materials. Slab--mounted unitsshould be at least 4 in. (102 mm) above the highest expected waterand runoff levels. Do not use unit if it has been under water.Step 4 — Rig and Place UnitRigging and handling of this equipment can be hazardous formany reasons due to the installation location (roofs, elevatedstructures, etc.).Only trained, qualified crane operators and ground support staffshould handle and install this equipment.When working with this equipment, observe precautions in theliterature, on tags, stickers, and labels attached to the equipment,and any other safety precautions that might apply.Training for operators of the lifting equipment should include, butnot be limited to, the following:

1. Application of the lifter to the load, and adjustment of thelifts to adapt to various sizes or kinds of loads.

2. Instruction in any special operation or precaution.3. Condition of the load as it relates to operation of the liftingkit, such as balance, temperature, etc.

Follow all applicable safety codes. Wear safety shoes and workgloves.INSPECTIONPrior to initial use, and at monthly intervals, all rigging shackles,clevis pins, and straps should be visually inspected for any damage,evidence of wear, structural deformation, or cracks. Particularattention should be paid to excessive wear at hoist hooking pointsand load support areas. Materials showing any kind of wear inthese areas must not be used and should be discarded.



Before installing or servicing system, always turn off mainpower to system. There may be more than one disconnectswitch. Turn off accessory heater power switch ifapplicable. Tag disconnect switch with a suitable warninglabel.

! WARNING

UNIT FALLING HAZARD


Never stand beneath rigged units or lift over people.

! WARNING

Rigging/Lifting of Unit

UNIT FALLING HAZARD


Large base units must be secured to common curb beforeallowing full weight of unit to rest on curb. Install screwsthrough curb into unit base rails while rigging crane is stillsupporting unit.

! WARNING

Lifting holes are provided in base rails as shown in Fig. 5 and 6.1. Leave top shipping skid on the unit for use as a spreader barto prevent the rigging straps from damaging the unit. If theskid is not available, use a spreader bar of sufficient lengthto protect the unit from damage.

2. Attach shackles, clevis pins, and straps to the base rails ofthe unit. Be sure materials are rated to hold the weight of theunit (See Fig. 7).

3. Attach a clevis of sufficient strength in the middle of thestraps. Adjust the clevis location to ensure unit is lifted levelwith the ground.

4. After unit is placed on the roof curb or mounting pad,remove the top skid.

UNIT FALLING HAZARD

Failure to follow this warning could result in personalinjury/death or property damage.

When straps are taut, the clevis should be a minimum of 36in. (914 mm) above the unit top cover.

! WARNING

After the unit is placed on the roof curb or mounting pad, removethe top crating.

50XT--A

7

ACCESS PANELS MUST BE IN PLACE WHEN RIGGING.PANNEAUX D'ACCES DOIT ÊTRE EN PLACE POUR MANIPULATION.

50CY502286 2.0

CAUTION - NOTICE TO RIGGERSPRUDENCE - AVIS AUX MANIPULATEUR

Use top skid as spreader bar. / Utiliser la palette du haut comme barre de répartition

SEAL STRIP MUST BE INPLACE BEFORE PLACINGUNIT ON ROOF CURB

DUCTS

DETAIL AVOIR DÉTAIL A

MINIMUM HEIGHT: 36" (914.4 mm)HAUTEUR MINIMUM

UNIT HEIGHTHAUTEUR D'UNITÉ

SEE DETAIL AVOIR DÉTAIL A

BANDE SCELLANT DOIT ÊTRE EN PLACE AVANT DE PLACER L'UNITÉ SUR LA BASE DE TOIT

A09079

CABINET MODELRIGGING WT

lb kg

Small50XT---A24 435 19750XT---A30 465 211

Large

50XT---A36 501 22750XT---A42 513 23350XT---A48 529 24050XT---A60 572 259

NOTE: See dimensional drawing for corner weight distribution.

Fig. 7 -- Suggested Rigging

Step 5 — Select and Install DuctworkThe design and installation of the duct system must be inaccordance with the standards of the NFPA for installation ofnon--residence type air conditioning and ventilating systems,NFPA 90A or residence type, NFPA 90B and/or local codes andordinances.Select and size ductwork, supply--air registers, and return air grillesaccording to ASHRAE (American Society of Heating,Refrigeration, and Air Conditioning Engineers) recommendations.The unit has duct flanges on the supply-- and return--air openingson the side of the unit.

ELECTRICAL OPERATION AND SAFETYHAZARD


For vertical supply and return units, tools or parts coulddrop into ductwork, therefore, install a 90 degree turn in thereturn ductwork between the unit and the conditioned space.If a 90 degree elbow cannot be installed, then a grille ofsufficient strength and density should be installed to preventobjects from falling into the conditioned space. Units withelectric heaters require 90 degree elbow in supply duct.

! WARNING

When designing and installing ductwork, consider the following:1. All units should have field--supplied filters or accessoryfilter rack installed in the return--air side of the unit.Recommended sizes for filters are shown in Table 1.

2. Avoid abrupt duct size increases and reductions. Abruptchange in duct size adversely affects air performance.

IMPORTANT: Use flexible connectors between ductwork andunit to prevent transmission of vibration. Use suitable gaskets toensure weather tight and airtight seal. When electric heat isinstalled, use fireproof canvas (or similar heat resistant material)connector between ductwork and unit discharge connection. Ifflexible duct is used, insert a sheet metal sleeve inside duct. Heatresistant duct connector (or sheet metal sleeve) must extend 24--in.(610 mm) from electric heater element.

3. Size ductwork for max possible air flow (See Table 1).4. Seal, insulate, and weatherproof all external ductwork. Seal,insulate and cover with a vapor barrier all ductwork passingthrough conditioned spaces. Follow latest Sheet Metal andAir Conditioning Contractors National Association(SMACNA) and Air Conditioning Contractors Association(ACCA) minimum installation standards for residentialheating and air conditioning systems.

5. Secure all ducts to building structure. Flash, weatherproof,and vibration--isolate duct openings in wall or roofaccording to good construction practices.

6. Read unit rating plate for any required clearances aroundductwork.

50XT--A

8

CONVERTING HORIZONTAL DISCHARGE UNITS TODOWNFLOW (VERTICAL) DISCHARGE UNITS



Before installing or servicing system, always turn off mainpower to system and tag lockout. There may be more thanone disconnect switch. Turn off accessory heater powerswitch if applicable.

! WARNING

1. Open all electrical disconnects and install lockout tag beforestarting any service work.

2. Remove horizontal (metal) duct covers to access vertical(downflow) discharge duct knockouts in unit basepan. (SeeFig. 8.)

3. Starting in a corner as shown in Fig. 9, score the panel inboth directions from the corner. Tap the panel out from thescored corner using a small hammer. Be careful and notdamage any other part of the unit.

4. If the unit ductwork is to be attached to vertical openingflanges on the unit base (jackstand applications only), do soat this time.

PROPERTY DAMAGE HAZARD

Failure to follow this caution may result in propertydamage.

Collect ALL screws that were removed. Do not leavescrews on rooftop as permanent damage to the roof mayoccur.

! WARNING

5. It is recommended that the base insulation around the peri-meter of the vertical return--air opening be secured to thebase with aluminum tape. Applicable local codes mayrequire aluminum tape to prevent exposed fiberglass.

6. Reinstall both horizontal duct covers. Ensure opening isair-- and watertight.

7. After completing unit conversion, perform all safety checksand power up unit.

NOTE: The design and installation of the duct system must be inaccordance with the standards of the NFPA for installation of nonresidence--type air conditioning and ventilating systems, NFPA90A or residence--type, NFPA 90B; and/or local codes andordinances.

Step 6 — Provide for Condensate DisposalNOTE: Ensure that condensate water disposal methods complywith local codes, restrictions, and practices.

The units dispose of condensate through a 3/4 --in. NPT femalefitting that exits on the compressor end of the unit. Condensatewater can be drained directly onto the roof in rooftop installations(where permitted) or onto a gravel apron in ground levelinstallations. Install a field--supplied condensate trap at end ofcondensate connection to ensure proper drainage. Make sure thatthe outlet of the trap is at least 1 in. (25 mm) lower than thedrain--pan condensate connection to prevent the pan fromoverflowing. Prime the trap with water. When using a gravel apron,make sure it slopes away from the unit.If the installation requires draining the condensate water away fromthe unit, install a field--supplied 2--in. (51 mm) trap at thecondensate connection to ensure proper drainage. Condensate trapis available as an accessory or is field--supplied. Make sure that theoutlet of the trap is at least 1 in. (25 mm) lower than the unitdrain--pan condensate connection to prevent the pan from

overflowing. Connect a drain tube using a minimum offield--supplied 3/4 --in. PVC or field--supplied 3/4 --in. copper pipeat outlet end of the 2 --in. (51 mm) trap (See Fig. 10). Do notundersize the tube. Pitch the drain trough downward at a slope of atleast 1 in. (25 mm) for every 10 ft. (3.1 m) of horizontal run. Besure to check the drain tube for leaks. Prime the trap at thebeginning of the cooling season start--up.

Horizontal Duct CoversA09076

BasepanDownflow(Vertical)SupplyKnockout

BasepanDownflow (Vertical)ReturnKnockout

A09093

Fig. 8 -- Supply and Return Duct Opening

122 1

3 3 44

1. Score groove in corner 1 in both directions as far as you can reach.2. Starting in corner 1, tap-out all sides with a small hammer. Be careful not to damage any other part of unit.3. If side from corner 3 to 4 is not accessible due to heat exchanger, pivot panel up and down by hand until remaining side breaks off.

INSTRUCTIONS FOR REMOVING DOWNSHOT PANELS

A09054

Fig. 9 -- Vertical (Downflow) Discharge Duct Knockouts

50XT--A

9

TRAPOUTLET

1-in. (25 mm) min.

2-in. (51 mm) min.

A09052

Fig. 10 -- Condensate Trap

Step 7 — Install Electrical Connections



The unit cabinet must have an uninterrupted, unbrokenelectrical ground. This ground may consist of an electricalwire connected to the unit ground screw in the controlcompartment, or conduit approved for electrical groundwhen installed in accordance with NEC, NFPA 70 NationalFire Protection Association (latest edition) (in Canada,Canadian Electrical Code CSA C22.1) and local electricalcodes.

! WARNING

HIGH--VOLTAGE CONNECTIONSThe unit must have a separate electrical service with afield--supplied, waterproof disconnect switch mounted at, or withinsight from, the unit. Refer to the unit rating plate, NEC and localcodes for maximum fuse/circuit breaker size and minimum circuitamps (ampacity) for wire sizing.The field--supplied disconnect may be mounted on the unit overthe high--voltage inlet hole (See Fig. 5 and 6).If the unit has an electric heater, a second disconnect may berequired. Consult the Installation, Start--Up, and ServiceInstructions provided with the accessory for electrical serviceconnections.Operation of unit on improper line voltage constitutes abuse andmay cause unit damage that could affect warranty.

UNIT COMPONENT DAMAGE HAZARD

Failure to follow this caution may result in damage to theunit being installed.1. Make all electrical connections in accordance with NECNFPA 70 (latest edition) and local electrical codesgoverning such wiring. In Canada, all electricalconnections must be in accordance with CSA standardC22.1 Canadian Electrical Code Part 1 and applicablelocal codes. Refer to unit wiring diagram.

2. Use only copper conductor for connections betweenfield--supplied electrical disconnect switch and unit. DONOT USE ALUMINUM WIRE.

3. Be sure that high--voltage power to unit is withinoperating voltage range indicated on unit rating plate.

4. Insulate low--voltage wires for highest voltage containedwithin conduit when low--voltage control wires are insame conduit as high--voltage wires.

5. Do not damage internal components when drillingthrough any panel to mount electrical hardware, conduit,etc.

! CAUTION

ROUTING POWER LEADS INTO UNITUse only copper wire between disconnect and unit. The highvoltage leads should be in a conduit until they enter the duct panel;conduit termination at the duct panel must be watertight. Run thehigh--voltage leads through the power entry knockout on thepower entry side panel. See Fig. 5 and 6 for location and size. Forsingle--phase units, connect leads to the black and yellow wires.CONNECTING GROUND LEAD TO GROUND SCREWConnect the ground lead to the chassis using the ground screw inthe wiring splice box (See Fig. 12).

50XT--A

10

Table 1 – Physical Data -- Unit 50XT--AUNIT SIZE 24 30 36 42 48 60NOMINAL CAPACITY ton 2 2--1/2 3 3--1/2 4 5SHIPPING WEIGHT (lb)

(kg)435197

465211

501227

513233

529240

572259

COMPRESSOR Two--Stage ScrollREFRIGERANT (R--410A) Quantity (lb)

(kg)10.3(4.7)

11.5(5.2)

9.7(4.4)

14.0(6.4)

15.5(7.0)

16.0(7.3)

EXPANSION DEVICE--HEATING AccuRaterORIFICE OD (in.) -- Left 0.042 0.038 0.035 0.040 0.038 0.046ORIFICE OD (in.) -- Right N/A 0.038 0.035 0.040 0.046 0.046

EXPANSION DEVICE--COOLING TXVSize 2 Ton 3 Ton 3 Ton 4 Ton 4 Ton 5 Ton

OUTDOOR COILRows…Fins/in. 2…21 2…21 2…21 2…21 2…21 2…21Face Area (sq. ft.) 13.6 15.3 17.5 19.4 19.4 23.3

OUTDOOR FANNominal Cfm 2700 2700 2800 2800 3300 3300Diameter 22 22 22 22 22 22Motor HP (RPM) 1/8 (825) 1/8 (825) 1/8 (825) 1/8 (825) 1/4 (1100) 1/3 (1110)

INDOOR COILRows…Fins/in. 3…17 3…17 3…17 3…17 3…17 4…17Face Area (sq. ft.) 3.7 3.7 4.7 4.7 5.7 5.7INDOOR FANNominal Airflow (Cfm)

Comfort Variable based on Comfort Settings (see User Interface instructions for more information).Efficiency 700 875 1050 1225 1400 1750

Max 800 1000 1200 1400 1600 2000Size in.

(mm)10x10

(254x254)10x10

(254x254)11x10

(279x254)11x10

(279x254)11x10

(279x254)11x10

(279x254)Motor HP (RPM) 1/2 1/2 3/4 3/4 3/4 1

HIGH--PRESSURE SWITCH (psig)Cutout 670 ± 10Reset (Auto) 470 ± 25

HIGH--PRESSURE SWITCH 2 (psig)(Compressor Solenoid)Cutout 565 ± 15Reset (Auto) 455 ± 15

LOSS--OF--CHARGE/LOW--PRESSURE SWITCH(Liquid Line) (psig)Cutout 23 ± 5Reset (Auto) 55 ± 5

RETURN--AIR FILTERS Throwaway in.*(mm)

20x24x1(508x610x25)

24x30x1(610x762x25)

24x36x1610x914x25)

*Recommended filter sizes for field---installed air filter grilles mounted on the wall or ceiling of the conditioned structure. Required filter sizes shown are based onthe larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity of 300 ft (91.4 mm) /minute for throwawaytype or 450 (137 mm) ft/minute for high---capacity type. Air filter pressure drop for non---standard filters must not exceed 0.08 in. wc.

50XT--A

11

INDOORTHERMOSTAT

DISCONNECTPER NEC

FROMPOWERSOURCE

RETURNAIR

TOP COVER

POWER ENTRY

CONTROL ENTRY

A09091

Fig. 11 -- Typical Installation

GROUND SCREW(IN SPLICE BOX)

YEL

BLK

GROUNDLEAD

SINGLE-PHASECONNECTIONSTO DISCONNECTPER NEC

LEGENDNEC – National Electrical Code

Field WiringSplice Connections

NOTE: Use copper wire only.

L1

L2

A06299

Fig. 12 -- Line Power Connections

ROUTING CONTROL POWER WIRESFor detailed instruction on the low voltage connections to the UserInterface (UI), refer to the UI installation guide.Form a drip--loop with the control leads before routing them intothe unit. Route the low voltage control leads through grommeted,low--voltage hole provided into unit (See Fig. 5 and 6). Connectuser interface leads to unit control power leads as shown in Fig. 14.The unit transformer supplies 24--v power for complete systemincluding accessory electrical heater. A circuit breaker is providedin the 24--v circuit as a protection device (See Fig. 17); see thecaution label on the transformer. Transformer is factory wired for230--v operation. If supply voltage is 208--v, rewire transformerprimary as described in Special Procedures for 208--v Operationsection.The fan coil board is fused by a board--mounted automotive fuseplaced in series with transformer SEC1 and R circuit (See F1 onFig. 15). The C circuit of transformer circuit is referenced to

chassis ground through a printed circuit run at SEC2 and metalcontrol board mounting eyelets. Check to be sure control board ismounted securely using both factory--installed screws.ACCESSORY INSTALLATIONA. Accessory Electric HeatersElectric heaters may be installed in 50XT--A per instructionssupplied with electric heater package. See unit rating plate forfactory--approved electric heater kits.NOTE: Units installed without electric heat should have afactory--supplied sheet metal block--off plate installed over heateropening. This reduces air leakage and formation of exteriorcondensation.B. Outdoor Air Temperature Sensor (OAT)


Failure to follow this caution may result in improper unitoperation.

The installation of an outdoor air temperature sensor (OAT)using the Infinity control board OAT terminals is required.Many Infinity features (auto humidity control, comfortrollback, etc.) will be lost if the OAT is not connected.For detailed mounting instructions for the OAT sensor,please refer to installation instructions shipped with theOAT.

! CAUTION

The OAT input is used to supply outdoor temperature data forsystem level functions and for temperature display on UI. Usingtwo wires of the field--supplied thermostat wire cable, wire the endsof the two black OAT pigtails. Wire the opposite ends of these twowires to the OAT provided with the UI. There is no polarity to beobserved.

50XT--A

12

NOTE: Mis--wiring OAT inputs will not cause damage to eitherInfinity control or thermistor. If the thermistor is wired incorrectly,no reading will appear at UI. Re--wire thermistor correctly fornormal operation.

C. Humidifier ConnectionsThe fan coil control board terminal marked HUM is provided forlow voltage (24--vac) control of a humidifier. No humidistat isrequired as UI monitors indoor humidity.When commanded to operate humidifier, the unit control willenergize the HUM output to turn humidifier on and de--energize

HUM output to turn humidifier off. Wire HUM and C terminalsdirectly to humidifier as shown in Fig. 14.SPECIAL PROCEDURES FOR 208--V OPERATIONBe sure unit disconnect switch is open.Disconnect the yellow primary lead from the transformer. See unitwiring label (See Fig. 17).Connect the yellow primary lead to the transformer terminallabeled 200--v.

HP/ACBOARD

FAN COILBOARD

A09107

Fig. 13 -- Control Plate

AB

DC

AABB

DDCC

Infinity Fan CoilBoard

Outdoor Air Thermistor(Supplied with UI)

FIELD CONNECTIONREQUIRED

(BLACK WIRES)

YYRR

OW

HUMC

OOWW

HUMHUMCC

LEGENDFactory WiringField Wiring

AB

DC

AABB

DDCC

Infinity HP/ACBoard

OAT

Y2Y2OO

Y1Y1W1W1

RRCC

OCT

Outdoor Coil ThermistorFACTORY CONNECTED

FACTORY WIRES PROVIDEDFOR FIELD CONNECTION

OF UTILITY CURTAILMENT

VIO

PNK

AB

DC

AABB

DDCC

UserInterface

HUMIDIFIER(24 VAC)

A06281

Fig. 14 -- Control Voltage Wiring Connections

50XT--A

13

PRE--START--UP

FIRE, EXPLOSION, ELECTRICAL SHOCK ANDENVIRONMENTAL HAZARD

Failure to follow this warning could result in personalinjury or death and/or property damage.1. Follow recognized safety practices and wear protectivegoggles when checking or servicing refrigerant system.

2. Do not operate compressor or provide any electric powerto unit unless compressor terminal cover is in place andsecured.

3. Do not remove compressor terminal cover until allelectrical sources are disconnected and tagged.

4. Relieve and recover all refrigerant from system beforetouching or disturbing anything inside terminal box ifrefrigerant leak is suspected around compressorterminals.

5. Never attempt to repair soldered connection whilerefrigerant system is under pressure.

6. Do not use torch to remove any component. Systemcontains oil and refrigerant under pressure.

7. To remove a component, wear protective goggles andproceed as follows:

a. Shut off electrical power to unit and installlockout tag.

b. Relieve and reclaim all refrigerant from systemusing both high-- and low--pressure ports.

c. Cut component connecting tubing with tubingcutter and remove component from unit.

d. Carefully unsweat remaining tubing stubs whennecessary. Oil can ignite when exposed to flame.

! WARNING

Use the Start--Up Checklist supplied at the end of this book andproceed as follows to inspect and prepare the unit for initialstart--up:

1. Remove all access panels.2. Read and follow instructions on all DANGER, WARNING,CAUTION, and INFORMATION labels attached to, orshipped with unit.

3. Make the following inspections:a. Inspect for shipping and handling damages, such asbroken lines, loose parts, disconnected wires, etc.

b. Inspect for oil at all refrigerant tubing connections andon unit base. Detecting oil generally indicates arefrigerant leak. Leak test all refrigerant tubingconnections using electronic leak detector, orliquid--soap solution. If a refrigerant leak is detected, seefollowing Check for Refrigerant Leaks section.

c. Inspect all field-- and factory--wiring connections. Besure that connections are completed and tight.

d. Ensure wires do not touch refrigerant tubing or sharpsheet metal edges.

e. Inspect coil fins. If damaged during shipping andhandling, carefully straighten fins with a fin comb.

4. Verify the following conditions:a. Make sure that outdoor fan blade is correctly positionedin fan orifice (See Fig. 20).

b. Make sure that condensate drain pan and trap are filledwith water to ensure proper drainage.

c. Make sure that all tools and miscellaneous loose partshave been removed.

5. Compressors are internally spring mounted. Do not loosenor remove compressor holddown bolts.

6. Each unit system has two Schrader--type ports, onelow--side Schrader fitting located on the suction line, andone high--side Schrader fitting located on the compressordischarge line. Be sure that caps on the ports are tight.

START--UPStep 1 — Unit Start--UpNOTE: Always check high-- and low--voltage supply to the unitcomponents. Check the integrity of the plug receptacle connectionsand unit wiring harness prior to assuming a component failure.A. LED DescriptionLEDs built into Infinity control boards provide installer or serviceperson information concerning operation and/or fault condition ofthe unit controls and the Indoor Fan ECM motor. This informationis also available at the system UI in text with basic troubleshootinginstructions. Careful use of information displayed will reduce theneed for extensive manual troubleshooting.Both the Fan Coil and Heat Pump (HP)/Air Conditioner (AC)boards have an amber LED and a green LED located near theSystem Communications connector (ABCD) (upper right center ofthe Fan Coil board, lower right corner of the HP/AC board asinstalled in the unit). The amber LED is the System Status LED,labeled STATUS. The green LED, labeled COMM, is used as anindicator of system communications status (See Fig 14--15).

SEC-2 SEC-1

F1 5

AB

CD

1

CO

MM

11

OA

T H

UM

C

W O

Y

R

HE

AT

ER

1

MOTOR

ST

AT

US

A03169

Fig. 15 -- Detail of Fan Coil Board

Status Codes will be displayed on the STATUS LED using thefollowing protocol:

1. The number of short flashes indicates first digit of code.2. The number of long flashes indicates second digit of code.3. A short flash is 0.25 seconds on. A long flash is 1 secondon.

4. The time between flashes is 0.25 seconds.5. The time between last short flash and first long flash is 1second.

6. The LEDs will be off for 2.5 seconds before repeating code.7. If multiple status codes are active concurrently, the highestpriority status code is displayed.

On the Fan Coil board, a second amber LED located at the bottomcenter of the control board, adjacent to the motor harness plug, isthe motor status LED, labeled MOTOR. The motor status LEDwill flash during normal blower operation.

50XT--A

14

LLS

Liquid Line Solenoid

UTILITY RELAY *

UTILITY SIGNALOPEN RELAY

* SUPPLIED BY UTILITY PROVIDER

A05247

Fig. 16 -- 2--Stage HP/AC Control Board

B. Control Start--Up and System CommunicationsTroubleshooting

On power up, green COMM LEDs will be turned off untilsuccessful system communications are established (this shouldhappen within 10 seconds). Once communications with UI aresuccessful, both COMM LEDs will be lit and held on. At the sametime, amber STATUS LEDs will be lit and held continuously onuntil a request for operating mode is received. The STATUS LEDwill be on any time unit is in idle mode.If, at any time, communications are not successful for a periodexceeding 2 minutes, the Infinity control will only allowemergency heating or cooling operation using a commonthermostat and the terminal strip connections on the two controlboards (see Non--Communicating Emergency Cooling/HeatingMode) and will display Status Code 16, System CommunicationFault, on amber STATUS LED. No further troubleshootinginformation will be available at UI until communications arere--established.If either COMM LED does not light within proper time period andstatus codes are not displayed;

1. Check system transformer high-- and low--voltage to be surethe system is powered.

2. Check ABCD connection on both boards.3. Check fuse on fan coil board to be sure it is not blown. Iffuse is open, check system wiring before replacing it to besure a short does not cause a failure of replacement fuse.

If COMM LED does not light within proper time period and statuscode is displayed,

1. Check system wiring to be sure UI is powered andconnections are made A to A, B to B, etc. and wiring is notshorted. Mis--wiring or shorting of the ABCDcommunications wiring will not allow successfulcommunications.

NOTE: Shorting or mis--wiring low--voltage system wiring willnot cause damage to unit control or UI but may cause low voltagefuse to open.C. Indoor Fan Motor (IFM) TroubleshootingThe indoor fan is driven by an Electronic Computated Motor(ECM) which consists of two parts: the control module and themotor winding section. Do not assume motor or module isdefective if it will not start. Use the designed--in LED informationaids and follow troubleshooting steps described below beforereplacing motor control module or entire motor. Motor controlmodule is available as a replacement part.VERIFY MOTOR WINDING SECTION



After disconnecting power from the ECM motor, wait atleast 5 minutes before removing the control section. Internalcapacitors require time to discharge.

! WARNING

Before proceeding to replace a motor control module:1. Check motor winding section to be sure it is functional.2. Remove motor control module section and unplug windingplug. Motor shaft should turn freely, resistance between anytwo motor leads should be similar and resistance betweenany motor lead and unpainted motor end should exceed100,000 ohms.

3. Failing any of these tests, entire ECM motor must bereplaced.

4. Passing all of the tests, motor control module alone can bereplaced.

50XT--A

15

A09092

Fig. 17 -- Wiring Schematic--50XT--A Single Phase

50XT--A

16

MOTOR TURNS SLOWLY1. Low static pressure loading of blower while access panel isremoved will cause blower to run slowly. Particularly at lowairflow requests. This is normal, do not assume a faultexists.

2. Recheck airflow and system static pressure using UI servicescreens with access panel in place.

NOTE: Blower motor faults will not cause a lockout of bloweroperation. The fan coil control will attempt to run the blower motoras long as UI maintains a demand for airflow. The control will notoperate electric heaters while a fault condition exists. The controlcommunicates with the motor at least once every five seconds,even when the motor is idle. If, during operation, the control doesnot communicate with the motor for more than 25 seconds, themotor will shut itself down and wait for communications to bereestablished.D. Using Fan Coil Control Motor LED in TroubleshootingThe MOTOR LED is connected to the blower motorcommunication line and works with the fan coil controlmicroprocessor and the STATUS LED to provide unit operationand troubleshooting information. When the motor is commandedto operate, the MOTOR LED will be turned on and will flash eachtime instructions are sent to the motor. When the motor iscommanded to stop, the MOTOR LED will be turned off.If the MOTOR LED is lit, flashing, and the motor is running, or ifthe MOTOR LED is off and the motor is stopped, operation isnormal and no motor fault exists.If the MOTOR LED is lit, flashing, and the motor does not run, orif the MOTOR LED is off and the motor is running, check theSTATUS LED for the Status Code. Refer to the troubleshootinginstructions for the indicated Status Code in Section E, Fan CoilControl Troubleshooting.E. Fan Coil Control TroubleshootingFan coil control faults indicated by flashing codes on the ambersystem STATUS LED can be resolved using troubleshootinginformation provided below. Codes are listed in order of theirpriority, highest to lowest. Though multiple faults can exist at anytime, only the highest priority code will be displayed on STATUSLED. Clearing the indicated fault when multiple faults exist willcause the next highest priority Status Code to be flashed. Allexisting faults, as well as a fault history, can be viewed at UI.STATUS CODE 45, CONTROL BOARD TEST FAULTFan coil control has failed internal start--up tests and must bereplaced. No other service procedure will correct.STATUS CODE 37, HEATER OUTPUT SENSED “ON” WHENNOT ENERGIZED:Fan coil control is provided with circuitry to detect presence of a24--vac signal on electric heater stage 1 and stage 2 outputs.If fan coil control detects a 24--vac signal on either heater stageoutput and it is not supplying signal, Status Code 37 will bedisplayed on STATUS LED. Control will turn off output andcommand blower motor to supply an airflow determined to be safefor current operation mode with electric heaters energized.To find the fault:

1. Stop all system operations at UI and check heater stage24--vac outputs.

2. Disconnect electric heater at power and check heater wiringfor faults. See Status Code 36 for more information.

STATUS CODE 44, MOTOR COMMUNICATION FAULTWhen motor is commanded to operate, the MOTOR LED will beturned on and will flash each time instructions are sent to themotor.When the motor is commanded to stop, the MOTOR LED will beturned off. The MOTOR LED will not flash to indicatecommunications when it is turned off.

Fan coil control is constantly communicating with the motor, evenwhen the motor and MOTOR LED are off. If motor does notacknowledge receipt of communications, the fan coil control willdisplay Status Code 44 on STATUS LED and continue to try tocommunicate with the motor. If motor acknowledgescommunication, status code will be cleared.If MOTOR LED is lit and flashing and motor does not run:

1. Check the STATUS LED. If STATUS LED is indicating aStatus 44 code, check the motor wiring harness for properconnection to control and motor receptacles.

2. Check motor wiring harness to be sure all wiring complieswith wiring diagram description, makes a complete circuitfrom connector to connector, and is not shorted.

3. Check 12--vdc low voltage supply to motor at pins 1 (+)and 2 (--) of motor header connection to fan coil control.

If all checks are normal, fan coil control is good and controlmodule on motor may need replacement. Check motor and MotorControl Module following the instructions in Section C, IndoorFan Motor Troubleshooting.If the MOTOR LED is off, STATUS LED is indicating a StatusCode 44 and motor is running:

1. Disconnect the motor harness at the fan coil control. Ifmotor continues to run, fan coil control is good and controlmodule on motor may need replacement.

STATUS CODE 25, INVALID MOTOR / MODEL SELECTIONOn initial start--up, the fan coil control shall poll motor for its sizedata and check unit size data stored in the control memory.

1. If motor size is incorrect for unit size or size data is invalid,Status Code 25 will be displayed on STATUS LED.

2. If model size data is missing (as is the case when areplacement fan coil control board is installed), system UIwill prompt installer to enter correct model size from a listof valid sizes.

3. If motor size is incorrect for model size, motor must bereplaced with proper size motor. Fan coil control will notrespond to operation requests until this fault condition isresolved.

STATUS CODE 26, INVALID HEATER SIZEOn initial power--up, fan coil control will write into memoryelectric heater size as read from heater if heater is provided withIdentifier Resistor (IDR). Heater size must be valid for the installedunit. Fan coil control will read IDR value connected to pins 1 and 2of heater harness connector. If no resistor is found, system UI willprompt installer to verify that no heater is installed. Verifying thatthis is correct will establish that the unit is operating without anelectric heater accessory. Upon choosing negative option, installerwill be prompted to select heater size installed from a list of validheater sizes for unit size installed.If heater ID resistor value read is invalid, Status Code 26 will bedisplayed on STATUS LED.If heater installed is equipped with a resistor connected to pins 1and 2 of heater harness connector and status code 26 is displayedon STATUS LED:

1. Check wiring harness connections to be sure connectionsare secure.

2. If symptoms persist, disconnect wiring harness at fan coilcontrol board and check for a resistance value greater than5000 ohms.

3. Check for proper wiring of resistor assembly.4. Make sure heater size installed is an approved size for unitand size installed.

NOTE: Fan coil control will not operate electric heater until thisStatus Code is resolved. If the heater size is set through the UI, theheater will be operated as a single stage heater. If staging is desired,the IDR value must be read in by the unit control.

50XT--A

17

STATUS CODE 36, HEATER OUTPUT NOT SENSED WHENENERGIZEDFan coil control is provided with circuitry to detect presence of a24--vac signal on electric heater stage 1 and stage 2 outputs.If fan coil control energizes either heater stage and does not detectthe 24--vac signal on output, Status Code 36 will be displayed onthe STATUS LED, control will continue to energize heateroutput(s) and adjust blower operation to a safe airflow level forenergized electric heat stage(s).To find the fault:

1. Check for 24--vac on heater stage outputs. Fan coil controlor sensing circuit may be bad.

NOTE: It may be useful as an electric heater troubleshootingprocedure to disconnect the system communications to force StatusCode 16 enabling of emergency heat mode. It is difficult to knowwhich heater output is energized or not energized in normaloperation. When unit is operated in emergency heat mode usingelectric heaters, both outputs are energized and de--energizedtogether. Terminal strip inputs to fan coil control can then beconnected R to W to turn on both electric heat outputs. Heateroutput sensing circuits can then be checked to resolve Status Code36 or 37 problems.STATUS CODE 41, BLOWER MOTOR FAULTIf MOTOR LED is lit and flashing and motor does not run:

1. Check STATUS LED. If STATUS LED is indicating StatusCode 41, motor control has detected that the motor will notcome up to speed within 30 seconds of being commandedto run or that the motor has been slowed to below 250 rpmfor more than 10 seconds after coming up to speed. Motorwiring harness and fan coil control are operating properly,do not replace.

2. Check to be sure that the blower wheel is not rubbing thehousing.

3. Check motor to be sure that the motor shaft is not seized(motor control module must be removed and electronicsdisconnected from windings to perform this checkproperly).

4. Check motor windings section following instructions inSection C, Indoor Fan Motor Troubleshooting.

If all these checks are normal, the motor control module may needreplacement.STATUS CODE 16, SYSTEM COMMUNICATION FAULTIf, at any time, system communications are not successful for aperiod exceeding 2 minutes, the fan coil control will only allowemergency heating or cooling operation using a commonthermostat, and the terminal strip connections and will displayStatus code 16 on the amber STATUS LED (seeNon--Communicating Emergency Cooling/Heating Mode). Nofurther unit troubleshooting information will be available at the UIuntil communications are re--established.Check system wiring to be sure the UI is powered and connectionsare made A to A, B to B, etc., and wiring is not shorted.Mis--wiring or shorting of the ABCD communications wiring willnot allow successful communications. Correcting wiring faults willclear the code and re--establish communications.Shorting or mis--wiring the low voltage system wiring will notcause damage to unit control or to UI but may cause the lowvoltage fuse to open.STATUS CODE 46, BROWNOUT CONDITIONIf the secondary voltage of the transformer falls below 15--vac for aperiod exceeding 4 seconds, Status Code 46 will be displayed onSTATUS LED and the UI will command the control board to turnoff compressor.When secondary voltage rises above 17--vac for more than 4seconds, the brownout condition is cleared and normal system

operation will resume subject to any minimum compressoroff--delay function which may be in effect. Brownout does notaffect blower or electric heater operation.STATUS CODE 53, OUTDOOR AIR TEMPERATURESENSOR FAULTIf an OAT sensor is found at power--up, input is constantly checkedto be within a valid temperature range. If sensor is found to beopen or shorted at any time after initial validation, Status Code 53will be displayed at amber STATUS LED.Check for faults in wiring connecting sensor to OAT terminals.Using an Ohm meter, check resistance of thermistor for a short oropen condition.If thermistor is shorted or open, replace it to return the system tonormal operation. If fault is in the wiring connections, correctingthe fault will clear the code and return the system to normaloperation.NOTE: If fault condition is an open thermistor or a wiring problemthat appears to be an open thermistor and the power to the unit iscycled off, the fault code will be cleared on the next power--up butthe fault will remain and system operation will not be as expected.This is because on power--up, the unit control cannot discernthe difference between an open sensor or if a sensor is notinstalled.F. HP/AC Control TroubleshootingSee Table 2 for HP/AC control board status codes andtroubleshooting information.

Step 2 — Sequence of OperationThe 50XT--A packaged heat pump is designed for installation witha communicating UI. This unit will not respond to commandsprovided by a common thermostat except under certain emergencysituations described in Step 1—Start--Up.The UI uses temperature, humidity and other data supplied fromindoor and outdoor system components to control heating orcooling system for optimum comfort. The unit will be commandedby UI to supply airflow. The unit will operate the indoor fan atrequested airflow for most modes.The nominal requested airflow will be 350 cfm per ton of nominalcooling capacity as defined by unit size. Actual airflow request willbe adjusted from nominal using indoor and outdoor temperatureand indoor humidity data to optimize the system operation foroccupant comfort and system efficiency. Refer to UI literature forfurther system control details.Airflow during electric heater operation must be greater than aminimum level for safe operation. If UI instructs unit to turn onelectric heat and the requested airflow is less than the minimumlevel the fan coil control will override requested value.NOTE: Once the compressor has started and then has stopped, itshould not be started again until 4 minutes have elapsed. Thecooling cycle remains “on” until the room temperature drops topoint that is slightly below the cooling control setting of the UI.

50XT--A

18

Table 2 – Heat Pump/Air Conditioner Board Status Codes

OPERATION FAULT

AMBERLEDFLASHCODE

POSSIBLE CAUSE AND ACTION

Standby – no call for unit opera-tion None On solid,

no flash Normal operation.

Emergency Mode Standard Ther-mostat Control

Rapid, con-tinuousflashing

Unit being controlled by standard thermostat inputs instead of Infin-ity Control. Only high stage operation is available. This operatingmode should be used in emergency situations only.

Low Stage Cool/Heat Operation None 1, pause Normal operation.High Stage Cool/Heat Opera-tion None 2, pause Normal operation.

System Commu-nications Failure

16 Communication with UI lost. Check wiring to UI, indoor and outdoorunits.

Invalid ModelPlug 25 Control does not detect a model plug or detects an invalid model

plug. Unit will not operate without correct model plug.High---PressureSwitch Open 31 High---pressure switch trip. Check refrigerant charge, outdoor fan

operation and coils for airflow restrictions.Low---PressureSwitch Open 32 Low---pressure switch trip. Check refrigerant charge and indoor air

flow.

Control Fault 45 Outdoor unit control board has failed. Control board needs to bereplaced.

Brown Out(230 v) 46 Line voltage < 187v for at least 4 seconds. Compressor and fan

operation not allowed until voltage>190v. Verify line voltage.

No 230v at Unit 47There is no 230v at the contactor when indoor unit is powered andcooling/heating demand exists. Verify the disconnect is closed and230v wiring is connected to the unit.

Outdoor AirTemp SensorFault

53 Outdoor air sensor not reading or out of range. Ohm out sensorand check wiring.

Outdoor CoilSensor Fault 55 Coil sensor not reading or out of range. Ohm out sensor and check

wiring.Thermistors Outof Range 56 Improper relationship between coil sensor and outdoor air sensor.

Ohm out sensors and check wiring.

Low Stage Ther-mal Cutout 71

Compressor voltage sensed, then disappears while cooling or heat-ing demand exists. Possible causes are internal compressor over-load trip or start relay not releasing (if installed).

High Stage Ther-mal Cutout 72

Compressor voltage sensed, then disappears while cooling or heat-ing demand exists. Possible causes are internal compressor over-load trip or start relay not releasing (if installed).

ContactorShorted 73

Compressor voltage sensed when no demand for compressor op-eration exists. Contactor may be stuck closed or there is a wiringerror.

No 230V atCompressor 74 Compressor voltage not sensed when compressor should be start-

ing. Contactor may be stuck open or there is a wiring error.Low Stage Ther-mal Lockout 81 Thermal cutout occurs in three consecutive low/ high stage cycles.

Low stage locked out for 4 hours or until 24v power recycled.High Stage Ther-mal Lockout 82 Thermal cutout occurs in three consecutive high/low stage cycles.

High stage locked out for 4 hours or until 24v power recycled.

Low---PressureLockout 83

Low---pressure switch trip has occurred during 3 consecutivecycles. Unit operation locked out for 4 hours or until 24v powerrecycled.

High---PressureLockout 84

High---pressure switch trip has occurred during 3 consecutivecycles. Unit operation locked out for 4 hours or until 24v powerrecycled.

COOLING AND HEATING OPERATIONWith a call for first stage cooling, the outdoor fan, reversing valve,and low stage compressor are energized. If low--stage cannotsatisfy cooling demand, high--stage cooling is energized by the UI.After second stage is satisfied, the unit returns to low--stageoperation until first stage is satisfied or until second stage isrequired again. When both first stage and second stage cooling aresatisfied, the compressor will shut off. The reversing valve willremain energized until the control board power is removed or a callfor heating in initiated. With a call for heating, the outdoor fan andcompressor are energized. The compressor will operate in high orlow stage operation, as needed to meet the heating demand. When

the heating demand is satisfied, the compressor and fan will shutoff. The reversing valve is de--energized in the heating mode.NOTE: When two--stage unit is operating at low--stage, systemvapor (suction) pressure will be higher than a standard single--stagesystem or high--stage operation.

NOTE: Outdoor fan motor will continue to operate for oneminute after compressor shuts off, when outdoor ambient is greaterthan or equal to 100°F (38°C).

UTILITY INTERFACE WITH INFINITY CONTROLThe utility curtailment relay should be connected to factorysupplied pigtails (PINK, connected to R, VIOLET connected to Y2on the control board) located in the low voltage splice box (See

50XT--A

19

Fig. 14, 16 and 17). This input allows a power utility device tointerrupt compressor operation during peak load periods. When theutility sends a signal to shut the system down, the UI will display“Curtailment Active”.COMPRESSOR OPERATIONWhen the compressor is operating in low stage, the modulatingring is de--activated, allowing two internal bypass ports to close off33% of the scroll compression area so the system operates at partload capacity. The 24--volt solenoid coil is de--energized inlow--stage operation.When the compressor is operating at high stage, the modulatingring is activated, sealing the bypass ports, which allows thecompressor to operate at full load capacity. The 24--volt solenoidcoil is energized in high stage operation.CRANKCASE HEATER OPERATION (IF APPLICABLE)The crankcase heater is energized during off cycle below 65_F(18_C) outdoor air temperature.OUTDOOR FAN MOTOR OPERATIONThe outdoor unit control energizes the outdoor fan any time thecompressor is operating, except for defrost. The outdoor fanremains energized if a pressure switch or compressor overloadshould open. Outdoor fan motor will continue to operate for oneminute after the compressor shuts off when the outdoor ambient isgreater than or equal to 100_F (38_C).TIME DELAYSThe unit time delays include:S Five minute time delay to start cooling or heating operationwhen there is a call from the thermostat or user interface. Tobypass this feature, momentarily short and release ForcedDefrost pins.

S Five minute compressor re--cycle delay on return from abrown--out condition.

S Two minute time delay to return to standby operation from lastvalid communication (with Infinity only).

S One minute time delay of outdoor fan at termination of coolingmode when outdoor ambient is greater than or equal to 100_F(38_C).

S Fifteen second delay at termination of defrost before theauxiliary heat (W1) is de--energized.

S Twenty second delay at termination of defrost before the outdoorfan is energized.

S Thirty second compressor delay when quiet shift enabled.S There is no time delay between staging from low to high and fromhigh to low capacity; the compressor will change from low to highand from high to low capacity as demand dictates.

INFINITY CONTROLLED LOW AMBIENT COOLINGNOTE: When this unit is operating below 55_F (13_C) outdoortemperature, provisions must be made for low ambient operation.This unit is capable of low ambient cooling down to 0_F (18_C)ONLY when using the Infinity control. A low ambient kit is notrequired, and the outdoor fan motor does not need to be replacedfor Infinity controlled low ambient operation. Low ambientcooling must be enabled in the UI set--up. Fan may not begin tocycle until about 40_F (4_C) OAT. Fan will cycle based on coiland outdoor air temperature. Infinity controlled low ambient modeoperates as follows:S In high stage, fan is off when outdoor coil temp is <outdoor airtemperature plus 3_F (1.6°C) or outdoor fan has been ON for 30minutes. (Fan is turned off to allow refrigerant system tostabilize.)

S In low stage, fan is off when outdoor coil temp is <outdoor air

temperature plus 1_F (--6°C)or outdoor fan has been ON for 30minutes. (Fan is turned off to allow refrigerant system tostabilize.)

S In high stage and low stage, fan is on when outdoor coil temp >outdoor air temperature plus 25_F (13.8°C) or outdoor coil temp> 80_F (27_C) or if outdoor fan has been OFF for 30 minutes.(Fan is turned on to allow refrigerant system to stabilize.)

S Low--pressure switch is ignored for first 3 minutes during lowambient start up. After 3 minutes, if LPS trips, then outdoor fanmotor is turned off for 10 minutes, with the compressor running.If LPS closes within 10 minutes then cooling continues with theoutdoor fan cycling per the coil temperature routine listed abovefor the remainder of the cooling cycle. If the LPS does not closewithin 10 minutes, then the normal LPS trip response (shut downcooling operation and generate LPS trip error) will occur.

DEFROSTThis control offers 5 possible defrost interval times: 30, 60, 90, 120minutes, or AUTO.The defrost interval times: 30, 60, 90, and 120 -- minutes or AUTOare selected by the Infinity Control User Interface (the dip switchesare not used.)AUTO defrost adjusts the defrost interval time based on the lastdefrost time as follows:S When defrost time <3 minutes, the next defrost interval=120minutes.

S When defrost time 3--5 minutes, the next defrost interval=90minutes.

S When defrost time 5--7 minutes, the next defrost interval=60minutes.

S When defrost time >7 minutes, the next defrost interval=30minutes.

The HP/AC control board accumulates compressor run time. Asthe accumulated run time approaches the selected defrost intervaltime, the control board monitors the coil temperature sensor for adefrost demand. If a defrost demand exists, a defrost cycle will beinitiated at the end of the selected time interval. A defrost demandexists when the coil temperature is at or below 32_F (0_C) for 4minutes during the interval.The defrost cycle is terminated when the coil temperature reaches65_F (18_C) or 10 minutes has passed.If the coil temperature does not reach 32_F (0_C) within theinterval, the interval timer will be reset and start over.S Upon initial power up the first defrost interval is defaulted to 30minutes. Remaining intervals are at selected times.

S Defrost is only allowed to occur below 50_F (10_C) outdoorambient temperature.

DEFROST HOLDDefrost hold is not needed in a communicating system because theUser Interface will complete the defrost cycle before shutting downthe system.FORCED DEFROSTForced defrost is initiated with the User Interface.During a Forced Defrost:S If coil temperature is at defrost temperature of 32_F (0_C), andoutdoor air temperature is below 50_F (10_C), a full defrostsequence will occur.

S If coil temperature or outdoor air temperature do not meet theabove requirements, an abbreviated 30 second defrost will occur.

50XT--A

20

QUIET SHIFTQuiet Shift is a field--selectable defrost mode which may eliminateoccasional noise that could be heard at the start of the defrost cycleand restarting of the heating cycle. This feature must be enabled atthe UI. When activated, the following sequence of operation willoccur. Reversing valve will energize and compressor will turn offfor 30 seconds, then turn back on to complete defrost. At the endof the defrost cycle, the reversing valve de--energizes, compressorwill turn off for another 30 seconds, and the fan will turn off for 40seconds, before starting in the heating mode.

Step 3 — Check for Refrigerant LeaksLocate and repair refrigerant leaks and charge the unit as follows:

1. Use both high-- and low--pressure ports to relieve systempressure and reclaim remaining refrigerant.

2. Repair leak following accepted practices.NOTE: Install a filter drier whenever the system has been openedfor repair.

3. Check system for leaks using an approved method.4. Evacuate refrigerant system and reclaim refrigerant if noadditional leaks are found.

5. Charge unit with Puron (R--410A) refrigerant, using anaccurate scale. Refer to unit rating plate for required charge.

Step 4 — Start--Up AdjustmentsComplete the required procedures given in the Pre--Start--Upsection before starting the unit. Do not jumper any safety deviceswhen operating the unit. Do not operate the unit in cooling modewhen the outdoor temperature is below 40°F (4_C) (unlesslow--ambient operation is enabled in the UI). Do not rapid cyclethe compressor. Allow 5 min. between “on” cycles to preventcompressor damage.CHECKING COOLING AND HEATING CONTROLOPERATIONSee UI Installation Instructions for detailed system CHECKOUT.CHECKING AND ADJUSTING REFRIGERANT CHARGEThe refrigerant system is fully charged with Puron (R--410A)refrigerant and is tested and factory sealed.NOTE: Any adjustment to refrigerant charge must be done withunit operating in HIGH stage.NOTE: Adjustment of the refrigerant charge is not requiredunless the unit is suspected of not having the proper R--410Acharge. The charging label and the tables shown refer to systemtemperatures and pressures in cooling mode only. A refrigerantcharging label is attached to the outside of the unit. If charge levelis suspect in heating mode, reclaim all refrigerant and charge torating plate amount. (This information may be obtained from thephysical data table also.)

IMPORTANT: When evaluating the refrigerant charge, anindicated adjustment to the specified factory charge must always bevery minimal. If a substantial adjustment is indicated, an abnormal

condition exists somewhere in the cooling system, such asinsufficient airflow across either coil or both coils.

REFRIGERANT CHARGEThe amount of refrigerant charge is listed on the unit rating plateand/or the physical data table. Refer to the Refrigeration ServiceTechniques Manual, Refrigerants Section.NO CHARGECheck for leak. Use standard evacuating techniques. Afterevacuating system, weigh in the specified amount of refrigerant(refer to system rating plate).LOW CHARGE COOLINGUse Cooling Charging Chart (Fig. 19). Vary refrigerant until theconditions of the chart are met. Note that charging charts aredifferent from type normally used. Charts are based on chargingthe units to correct subcooling for the various operating conditions.Accurate pressure gauge and temperature sensing devices arerequired. Connect the pressure gauge to the service port on thesuction line. Mount the temperature sensing device on the suctionline and insulate it so that the outdoor ambient does not affect thereading. Indoor air CFM must be within the normal operatingrange of the unit.TO USE COOLING CHARGING CHARTSTake the liquid line temperature and read the manifold pressuregauges.Refer to the chart to determine what the liquid line temperatureshould be.NOTE: If the problem causing the inaccurate readings is arefrigerant leak, refer to Check for Refrigerant Leaks section.

INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTSNOTE: Be sure that all supply-- and return--air grilles are open,free from obstructions, and adjusted properly.

The 50XT--A unit utilizes state of the art ECM (ElectronicComputated Motor) ID Blower Motors. See UI instructions fordetailed information on adjusting airflow.NON--COMMUNICATING EMERGENCY COOLING /HEATING MODEThis mode of operation is provided only in the case where the UIhas failed or is otherwise unavailable. If communications cannot beestablished with the UI, the Infinity fan coil board will enable theR, C, Y, O, and W input terminals to allow simple thermostaticcontrol of the 50XT--A unit.For control with a standard thermostat, disconnect the ABCDconnectors from both control boards and using No. 18 AWGcolor--coded, insulated type 90°C minimum or equivalent wire,make the connections between the standard thermostat, the fan coilboard, and the HP/AC board per Fig. 18. Recommend the use ofinterconnecting wire with 105C, 600V, 2/64” insulation.The Infinity control will respond to cooling and heating demandswith the maximum safe airflow based on electric heat size (ifapplicable) and unit capacity.

50XT--A

21

A06297

Fig. 18 -- Non--Communicating Emergency Cooling/Heating Wiring Connections

A09109

Fig. 19 -- Cooling Charging Table--Subcooling

50XT--A

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Table 3 – Wet Coil Pressure Drop (in. wc)UNITSIZE

STANDARD CFM (SCFM)600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100

24 0.005 0.007 0.010 0.012 0.015 – – – – – – – – – – –30 – 0.007 0.010 0.012 0.015 0.018 0.021 0.024 – – – – – – – –36 – – – 0.019 0.023 0.027 0.032 0.037 0.042 0.047 – – – – – –42 – – – – 0.014 0.017 0.020 0.024 0.027 0.031 0.035 0.039 0.043 – – –48 – – – – – – 0.027 0.032 0.036 0.041 0.046 0.052 0.057 0.063 0.068 –60 – – – – – – – – – 0.029 0.032 0.036 0.040 0.045 0.049 0.053

Table 4 – Filter Pressure Drop Table (in. wc)FILTER SIZEin. (mm)

CFM500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300

20X20X1(508x508x25) 0.05 0.07 0.08 0.1 0.12 0.13 0.14 0.15 — — — — — — — — — — —

24X30X1(610x762x25) — — — — 0.05 0.6 0.07 0.07 0.08 0.09 0.1 — — — — — — — —

24X36X1(610x914x25) — — — — — — — 0.06 0.07 0.07 0.08 0.09 0.09 0.10 0.11 0.12 0.13 0.14 0.14

Table 5 – Electric Heat Pressure Drop TableSmall Cabinet: 24--30

CFM500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600

5 kw 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.04 0.06 0.077.2 kw 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.03 0.05 0.07 0.08 0.0910 kw 0.00 0.00 0.00 0.00 0.00 0.02 0.04 0.06 0.07 0.09 0.10 0.1115 kw 0.00 0.00 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18

Table 6 – Electric Heat Pressure Drop TableLarge Cabinet: 36--60

CFM1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500

5kw 0.00 0.00 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.127.2 kw 0.00 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.1310 kw 0.00 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.1315 kw 0.00 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.1520 kw 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15 0.16

MAINTENANCETo ensure continuing high performance, and to minimize thepossibility of premature equipment failure, periodic maintenancemust be performed on this equipment. This packaged airconditioner unit should be inspected at least once each year by aqualified service person. To troubleshoot unit, refer to Table 7,Troubleshooting Chart.NOTE TO EQUIPMENT OWNER: Consult your local dealerabout the availability of a maintenance contract.

PERSONAL INJURY AND UNIT DAMAGEHAZARD

Failure to follow this warning could result in personalinjury or death and possible unit component damage.

The ability to properly perform maintenance on thisequipment requires certain expertise, mechanical skills,tools and equipment. If you do not possess these, do notattempt to perform any maintenance on this equipment,other than those procedures recommended in the Owner’sManual.

! WARNING


Failure to follow these warnings could result in personalinjury or death:1. Turn off electrical power to the unit and tag beforeperforming any maintenance or service on this unit.

2. Use extreme caution when removing panels and parts.3. Never place anything combustible either on or in contactwith the unit.

! WARNING

UNIT OPERATION HAZARD

Failure to follow this caution may result in equipmentdamage or improper operation.

Errors made when reconnecting wires may cause improperand dangerous operation. Label all wires prior todisconnecting when servicing.

CAUTION!

The minimum maintenance requirements for this equipment are asfollows:

1. Inspect air filter(s) each month. Clean or replace whennecessary.

2. Inspect indoor coil, drain pan, and condensate drain eachcooling season for cleanliness. Clean when necessary.

3. Inspect blower motor and wheel for cleanliness eachcooling season. Clean when necessary.

4. Check electrical connections for tightness and controls forproper operation each cooling season. Service whennecessary.

50XT--A

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Step 1 — Air FilterIMPORTANT: Never operate the unit without a suitable air filterin the return--air duct system. Always replace the filter with thesame dimensional size and type as originally installed. See Table 1for recommended filter sizes.

Inspect air filter(s) at least once each month and replace(throwaway--type) or clean (cleanable--type) at least twice duringeach cooling season and twice during the heating season, orwhenever the filter becomes clogged with dust and lint.

Step 2 — Indoor Fan and Motor (IFM)NOTE: All motors are pre--lubricated. Do not attempt to lubricatethese motors.

For longer life, operating economy, and continuing efficiency,clean accumulated dirt and grease from the blower wheel andmotor annually.



Disconnect and tag electrical power to the unit beforecleaning and lubricating the blower motor and wheel.

! WARNING

Step 3 — Outdoor Coil, Indoor Coil, andCondensateDrain PanInspect the condenser coil, evaporator coil, and condensate drainpan at least once each year.The coils are easily cleaned when dry; therefore, inspect and cleanthe coils either before or after each cooling season. Remove allobstructions, including weeds and shrubs, that interfere with theairflow through the condenser coil. Straighten bent fins with a fincomb. If coated with dirt or lint, clean the coils with a vacuumcleaner, using the soft brush attachment. Be careful not to bend thefins. If coated with oil or grease, clean the coils with a milddetergent and water solution. Rinse coils with clear water, using agarden hose. Be careful not to splash water on motors, insulation,wiring, or air filter(s). For best results, spray condenser coil finsfrom inside to outside the unit. On units with an outer and innercondenser coil, be sure to clean between the coils. Be sure to flushall dirt and debris from the unit base.Inspect the drain pan and condensate drain line when inspectingthe coils. Clean the drain pan and condensate drain by removing allforeign matter from the pan. Flush the pan and drain trough withclear water. Do not splash water on the insulation, motor, wiring, orair filter(s). If the drain trough is restricted, clear it with a“plumbers snake” or similar probe device.

Step 4 — Outdoor Fan

UNIT OPERATION HAZARD

Failure to follow this caution may result in damage to unitcomponents.

Keep the condenser fan free from all obstructions to ensureproper cooling operation. Never place articles on top of theunit.

CAUTION!

1. Remove 4 screws holding outdoor grille and motor to topcover.

2. Turn motor/grille assembly upside down on top cover toexpose fan blade.

3. Inspect the fan blades for cracks or bends.4. If fan needs to be removed, loosen setscrew and slide fan offmotor shaft.

5. When replacing fan blade, position blade according to thetable shown in Fig. 20.

6. Ensure that set screw engages the flat area on the motorshaft when tightening.

7. Replace grille.

Infinity TopA06035

UNIT SIZE “A” DIM IN. (MM)

24 1 (26)30 1 (26)36 1 (26)42 1 (26)48 11/32 (9)60 9/16 (14)

Fig. 20 -- Outdoor Fan Blade Clearance

Step 5 — Electrical Controls and WiringInspect and check the electrical controls and wiring annually. Besure to turn off the electrical power to the unit.Remove access panel to locate all the electrical controls and wiring.Check all electrical connections for tightness. Tighten all screwconnections. If any smoky or burned connections are noticed,disassemble the connection, clean all the parts, re--strip the wireend and reassemble the connection properly and securely.After inspecting the electrical controls and wiring, replace all thepanels. Start the unit, and observe at least one complete coolingcycle to ensure proper operation. If discrepancies are observed inoperating cycle, or if a suspected malfunction has occurred, checkeach electrical component with the proper electricalinstrumentation. Refer to the unit wiring label when making thesechecks.

Step 6 — Refrigerant CircuitInspect all refrigerant tubing connections and the unit base for oilaccumulation annually. Detecting oil generally indicates arefrigerant leak.If oil is detected or if low performance is suspected, leak test allrefrigerant tubing using an electronic leak detector, or liquid--soapsolution. If a refrigerant leak is detected, refer to Check forRefrigerant Leaks section.If no refrigerant leaks are found and low performance is suspected,refer to Checking and Adjusting Refrigerant Charge section.

Step 7 — Indoor AirflowThe heating and/or cooling airflow does not require checkingunless improper performance is suspected. If a problem exists, besure that all supply-- and return--air grilles are open and free fromobstructions, and that the air filter is clean.

Step 8 — Metering Devices--TXV & AccuRater®

PistonThis unit uses 2 types of metering devices. The outdoor meteringdevice is a fixed orifice and is contained in the brass--hex body inthe liquid line feeding the outdoor coils. The indoor meteringdevice is a TXV--type device. No maintenance should be required.

50XT--A

24

Step 9 — Pressure SwitchesPressure switches are protective devices integrated into the controlcircuit (low voltage). They shut off compressor if abnormally highor low pressures are present in the refrigeration circuit. Thesepressure switches are specifically designed to operate with Puron(R--410A) systems. R--22 pressure switches must not be used asreplacements for the Puron (R--410A) system.Loss--of--Charge (Low Pressure) SwitchThis switch is located on the liquid line and protects against lowsuction pressures caused by such events as loss of charge, lowairflow across indoor coil, dirty filters, etc. It opens if the systempressure drops to about 20 psig. If system pressure is above this,switch should be closed.High--Pressure Switches (HPS & HPS2)The high--pressure switches are located on the discharge line andprotects against excessive condenser coil pressure. HPS opens at670 psig shutting down the compressor, while HPS2 opens at 565,limiting the compressor to low--stage operation only.High pressure may be caused by a dirty outdoor coil, failed fanmotor, or outdoor air recirculation.To check switches:

1. Turn off all power to unit.2. Disconnect leads on switch.3. Apply ohm meter leads across switch. You should havecontinuity on a good switch.

NOTE: Because these switches are attached to refrigerationsystem under pressure, it is not advisable to remove this device fortroubleshooting unless you are reasonably certain that a problemexists. If switch must be removed, remove and recover all systemcharge so that pressure gauges read 0 psi. Never open systemwithout breaking vacuum with dry nitrogen.

Step 10 — Copeland Scroll Compressor (PuronRefrigerant)The compressor used in this product is specifically designed tooperate with Puron (R--410A) refrigerant and cannot beinterchanged.The compressor is an electrical (as well as mechanical) device.Exercise extreme caution when working near compressors. Powershould be shut off, if possible, for most troubleshooting techniques.Refrigerants present additional safety hazards.

EXPLOSION, FIRE HAZARD

Failure to follow this warning could result in personalinjury or death and/or property damage.

Wear safety glasses and gloves when handling refrigerants.Keep torches and other ignition sources away fromrefrigerants and oils.

! WARNING

The scroll compressor pumps refrigerant throughout the system bythe interaction of a stationary and an orbiting scroll. The scrollcompressor has no dynamic suction or discharge valves, and it ismore tolerant of stresses caused by debris, liquid slugging, andflooded starts. The compressor is equipped with noise reducingshutdown device and an internal pressure--relief port. The noisereducing shutdown device prevents the scroll from turningbackwards and replaces the need for a cycle protector. Thepressure--relief port is a safety device, designed to protect againstextreme high pressure. The relief port has an operating rangebetween 550 and 625 psi differential pressure.The Copeland scroll compressor uses Mobil 3MA POE oil.This is the only oil allowed for oil recharge.

Step 11 — Refrigerant SystemThis step covers the refrigerant system of the 50XT--A, includingthe compressor oil needed, servicing systems on roofs containingsynthetic materials, the filter drier, and refrigerant charging.REFRIGERANT

UNIT OPERATION, SAFETY ANDENVIRONMENTAL HAZARD

Failure to follow this warning could result in personalinjury or equipment damage.

This system uses Puron (R--410A) refrigerant which hashigher operating pressures than R--22 and other refrigerants.No other refrigerant may be used in this system. Gauge set,hoses, and recovery system must be designed to handlePuron. If you are unsure, consult the equipmentmanufacturer.

WARNING!

COMPRESSOR OILThe Copeland scroll compressor uses 3MAF POE oil. If additionaloil is needed, use Uniqema RL32--3MAF. If this oil is notavailable, use Copeland Ultra 32 CC or Mobil Arctic EAL22 CC.This oil is extremely hygroscopic, meaning it absorbs waterreadily. POE oils can absorb 15 times as much water as other oilsdesigned to HCFC and CFC refrigerants. Take all necessaryprecautions to avoild exposure of the oil to the atmosphere.SERVICING SYSTEMS ON ROOFS WITH SYNTHETICMATERIALSPOE (polyolester) compressor lubricants are known to cause longterm damage to some synthetic roofing materials.Exposure, even if immediately cleaned up, may causeembrittlement (leading to cracking) to occur in one year or more.When performing any service that may risk exposure ofcompressor oil to the roof, take appropriate precautions to protectroofing. Procedures which risk oil leakage include, but are notlimited to, compressor replacement, repairing refrigerant leaks, andreplacing refrigerant components such as filter drier, pressureswitch, metering device, coil, accumulator, or reversing valve.Synthetic Roof Precautionary Procedure

1. Cover extended roof working area with an impermeablepolyethylene (plastic) drip cloth or tarp. Cover anapproximate 10x10 ft (3x3 m) area.

2. Cover area in front of the unit service panel with a terrycloth shop towel to absorb lubricant spills and preventrun--offs, and protect drop cloth from tears caused by toolsor components.

3. Place terry cloth shop towel inside unit immediately undercomponent(s) to be serviced and prevent lubricant run--offsthrough the louvered openings in the unit base.

4. Perform required service.5. Remove and dispose of any oil--contaminated material perlocal codes.

LIQUID--LINE BI--FLOW FILTER DRIERThe bi--flow filter drier is specifically designed to operate withPuron. Use only factory--authorized components. Filter drier mustbe replaced whenever the refrigerant system is opened. Whenremoving a filter drier, use a tubing cutter to cut the drier from thesystem. Do not unsweat a filter drier from the system. Heat fromunsweating will release moisture and contaminants from drier intosystem.PURON (R--410A) REFRIGERANT CHARGINGRefer to unit information plate and charging chart. Some R--410Arefrigerant cylinders contain a dip tube to allow liquidrefrigerant to flow from cylinder in upright position. Forcylinders equipped with a dip tube, charge Puron units with

50XT--A

25

cylinder in upright position and a commercial metering device inmanifold hose. Charge refrigerant into suction line.

TROUBLESHOOTINGLED DESCRIPTIONLEDs built into Infinity control boards provide installer or serviceperson information concerning operation and/or fault condition ofthe unit controls and ECM motor. This information is alsoavailable at the system UI in text with basic troubleshootinginstructions. Careful use of information displayed will reduce theneed for extensive manual troubleshooting. See section B andTable 2, as well as the UI instructions, for additional information.Additional Troubleshooting information can be found in Table 7.MAJOR COMPONENTS2--STAGE HP/AC BOARDThe two--stage HP/AC control board controls the followingfunctions:-- Low-- and high--stage compressor operation-- Outdoor fan motor operation-- Reversing valve operation-- Defrost operation-- Low ambient cooling-- Crankcase heater operation-- Compressor external protection-- Pressure switch monitoring-- Time delayFAN COIL BOARDThe fan coil board controls the following functions:-- Indoor fan operation-- Electric heat (if applicable)SYSTEMS COMMUNICATION FAILUREIf communication with the Infinity Control is lost with the UI, thecontrols will flash the appropriate fault codes. Check the wiring tothe UI, indoor and outdoor units.MODEL PLUGThe HP/AC control board must have a valid model plug to operate.If a valid model plug is not detected, it will not operate and thecontrol will flash the appropriate fault code, shown in Table 2.PRESSURE SWITCH PROTECTIONThe unit is equipped with high-- and low--pressure switches. If thecontrol senses the opening of a high or low pressure switch, it willrespond as follows:

1. De--energize the compressor contactor (HPS1 & LPS) or thecompressor solenoid contactor (HPS2).

2. Keep the outdoor fan operating for 15 minutes.3. Display the appropriate fault codes.4. After a 15 minute delay, if there is still a call for cooling andthe LPS or HPS is reset, the compressor contactor isenergized.

5. If LPS or HPS has not closed after a 15 minute delay, theoutdoor fan is turned off. If the open switch closes anytimeafter the 15--minute delay, then resume operation with a callfor cooling.

6. If LPS or HPS trips 3 consecutive cycles, the unit operationis locked out for 4 hours.

7. In the event of a high--pressure switch trip or high pressurelockout, check the refrigerant charge, outdoor fan operationand outdoor coil for airflow restrictions.

8. In the event of a low--pressure switch trip or low pressurelockout, check the refrigerant charge and indoor airflow.

CONTROL FAULTIf the HP/AC control board has failed, the control will flash theappropriate fault code (See Table 2). The control board should bereplaced.BROWN OUT PROTECTIONIf the line voltage is less than 187v for at least 4 seconds, theappropriate compressor contactor and fan relay are de--energized.Compressor and fan operation are not allowed until voltage is aminimum of 190v. The control will flash the appropriate faultcode (See Table 2).230V LINE (POWER DISCONNECT) DETECTIONIf there is no 230v at the compressor contactor when the unit ispowered and cooling demand exists, the appropriate error code isdisplayed. Verify that the disconnect is closed and 230v wiring isconnected to the unit.COMPRESSOR VOLTAGE SENSINGThe control board input terminals VS and L2 (See Fig. 16) areused to detect compressor voltage status, and alert the user ofpotential problems. The control continuously monitors the highvoltage on the run capacitor of the compressor motor. Voltageshould be present any time the compressor contactor is energized,and voltage should not be present when the contactor isde--energized.CONTACTOR SHORTED DETECTIONIf there is compressor voltage sensed when there is no demand forcompressor operation, the contactor may be stuck closed or there isa wiring error. The control will flash the appropriate fault code.COMPRESSOR THERMAL CUTOUTIf the control senses the compressor voltage after start--up, and isthen absent for 10 consecutive seconds while cooling demandexists, the thermal protector is open. The control de--energizes thecompressor contactor for 15 minutes, but continues to operate theoutdoor fan. The control Status LED will flash the appropriatecode shown in Table 2. After 15 minutes, with a call for low orhigh stage cooling, the compressor contactor is energized. If thethermal protector has not re--set, the outdoor fan is turned off. Ifthe call for cooling continues, the control will energize thecompressor contactor every 15 minutes. If the thermal protectorcloses (at the next 15 minute interval), check the unit will resumeoperation.If the thermal cutout trips for three consecutive cycles, then unitoperation is locked out for 4 hours and the appropriate fault code isdisplayed.NO 230V AT COMPRESSORIf the compressor voltage is not sensed when the compressorshould be starting, the contactor may be stuck open or there is awiring error. The control will flash the appropriate fault code.Check the contactor and control box wiring.TROUBLESHOOTING UNIT FOR PROPER SWITCHINGBETWEEN LOW & HIGH STAGESCheck the suction pressures at the service valves. Suction pressureshould be reduced by 3--10% when switching from low to highcapacity.NOTE: The liquid pressures are very similar between low andhigh stage operation, so liquid pressure should not be used fortroubleshooting.

Compressor current should increase 20--45% when switching fromlow to high stage. The compressor solenoid, when energized inhigh stage, should measure 24vac.

50XT--A

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COMPRESSOR INTERNAL RELIEFThe compressor is protected by an internal pressure relief (IPR)which relieves discharge gas into compressor shell whendifferential between suction and discharge pressures exceeds 550 --625 psi. The compressor is also protected by an internal overloadattached to motor windings.TEMPERATURE THERMISTORSThermistors are electronic devices which sense temperature. As thetemperature increases, the resistance decreases. Thermistors areused to sense outdoor ambient (OAT) and coil temperature (OCT).Refer to Fig. 21 for resistance values versus temperature. See Fig.22 for OCT location.If the outdoor ambient or coil thermistor should fail, the HP/ACcontrol will flash the appropriate fault code (See Table 2).IMPORTANT: Coil thermistor is factory mounted. Check toinsure thermistor is mounted properly. Outdoor air thermistor(OAT) is field mounted and connected. Verify that the OAT hasbeen properly installed.

0

10

20

30

40

50

60

70

80

90

0 20 40 60 80 100 120TEMPERATURE (DEG. F)

RE

SIS

TA

NC

E (

KO

HM

S)

THERMISTOR CURVE

A91431

Fig. 21 -- Resistance Values Versus TemperatureTHERMISTOR SENSOR COMPARISONThe control continuously monitors and compares the outdoor airtemperature sensor and outdoor coil temperature sensor to ensureproper operating conditions. The comparison is:S In cooling mode, if the outdoor air sensor indicates ≥ 10 _F(--12°C) warmer than the coil sensor (or) the outdoor air sensorindicates ≥ 20_F (--7°C) cooler than the coil sensor, the sensors areout of range.

S In heating if the outdoor air sensor indicates ≥ 35_F (2°C)warmer than the coil sensor (or) the outdoor air sensor indicates≥ 10_F (--12°C) cooler than the coil sensor, the sensors are out ofrange.

If the sensors are out of range, the control will flash the appropriatefault code as shown in Table 2.The thermistor comparison is not performed during low ambientcooling operation.FAILED THERMISTOR DEFAULT OPERATIONFactory defaults have been provided in the event of failure ofoutdoor air thermistor and/or coil thermistor.

If the OAT sensor should fail, low ambient cooling will not beallowed and the one--minute outdoor fan off delay will not occur.Defrost will be initiated based on coil temperature and time.If the OCT sensor should fail, low ambient cooling will not beallowed. Defrost will occur at each time interval during heatingoperation, but will terminate after 5 minutes.If there is a thermistor out of range error, defrost will occur at eachtime interval during heating operation, but will terminate after 5minutes.Refer to the Troubleshooting Chart (Table 7) for additionaltroubleshooting information.

A06311

Fig. 22 -- Outdoor Coil Thermistor (OCT) Attachment

FINAL CHECKSIMPORTANT: Before leaving job, be sure to do the following:

1. Ensure that all wiring is routed away from tubing and sheetmetal edges to prevent rub--through or wire pinching.

2. Ensure that all wiring and tubing is secure in unit beforeadding panels and covers. Securely fasten all panels andcovers.

3. Tighten service valve stem caps to 1/2--turn past fingertight.

4. Leave Users Manual with owner. Explain system operationand periodic maintenance requirements outlined in manual.

5. Fill out Dealer Installation Checklist and place in customerfile.

CARE AND MAINTENANCEFor continuing high performance and to minimize possibleequipment failure, periodic maintenance must be performed on thisequipment.Frequency of maintenance may vary depending upon geographicareas, such as coastal applications. See Users Manual forinformation.

50XT--A

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HEAT PUMP WITH PURONREFRIGERATION SECTION QUICK--REFERENCE GUIDE

Puron refrigerant operates at 50--70 percent higher pressures than R--22. Be sure that servicing equipment and replacement components aredesigned to operate with Puron. Puron refrigerant cylinders are rose colored.S Puron refrigerant cylinders manufactured prior to March 1, 1999, have a dip tube that allows liquid to flow out of cylinder in uprightposition. Cylinders manufactured March 1, 1999 and later DO NOT have a dip tube and MUST be positioned upside down to allow liquidto flow.

S Recovery cylinder service pressure rating must be 400 psig. DOT 4BA400 or DOT BW400.S Puron systems should be charged with liquid refrigerant. Use a commercial--type metering device in the manifold hose.S Manifold sets should be minimum700 psig high side and 180 psig low side with 550 psig low side retard.S Use hoses with minimum 700 psig service pressure rating.S Leak detectors should be designed to detect HFC refrigerant.S Puron, as with other HFCs, is only compatible with POE oils.S Vacuum pumps will not remove moisture from oil.S Only use factory--specified liquid--line filter driers with rated working pressures no less than 600 psig.S Do not install a suction--line filter drier in liquid line.S POE oils absorb moisture rapidly. Do not expose oil to atmosphere.S POE oils may cause damage to certain plastics and roofing materials.S Wrap all filter driers and service valves with wet cloth when brazing.S A Puron liquid--line filter drier is required on every unit.S Do not use an R--22 TXV.S Never open system to atmosphere while it is under a vacuum.S When system must be opened for service, break vacuum with dry nitrogen and replace filter driers.S Do not vent Puron into the atmosphere.S Observe all warnings, cautions, and bold text.S Do not leave Puron suction line driers in place for more than 72 hrs.

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Table 7 – Troubleshooting Chart

SYMPTOM CAUSE REMEDY

Compressor and outdoor fanwill not start

Power failure Call power companyFuse blown or circuit breaker tripped Replace fuse or reset circuit breaker

Defective contactor, transformer, HP/AC control board,or high--pressure, loss--of--charge or low--pressureswitch

Replace component

Insufficient line voltage Determine cause and correct

Incorrect or faulty wiring Check wiring diagram and rewire correctly

User Interface setting too low/too high Reset UI setting

DO NOT bypass this compressor timedelay–wait for 5 minutes until time--delayrelay is de--energized

Units have a 5--minute time delay

Compressor will not start but outdoor fanruns

Faulty wiring or circuitLoose connections in compressor Check wiring and repair or replace

Compressor motor burned out, seized, or Determine causeinternal overload open Replace compressorDefective run capacitor, overload, or PTC (positivetemperature coefficient) thermistor Determine cause and replace

Low input voltage Determine cause and correct

Compressor cycles (other than normally satis-fying) cooling/heating calls

Refrigerant overcharge or underchargeRecover refrigerant, evacuate system, and re-charge to capacities shown on rating plate

Defective compressor Replace and determine causeInsufficient line voltage Determine cause and correctBlocked outdoor coil Determine cause and correctDefective run/start capacitor, overload or start relay Determine cause and replaceFaulty outdoor fan motor or capacitor ReplaceDamaged reversing valve Determine cause and correctRestriction in refrigerant system Locate restriction and remove

Compressor operates continuously

Dirty air filter Replace filterUnit undersized for load Decrease load or increase unit sizeUI temperature set too low/too high Reset UI settingLow refrigerant charge Locate leak, repair, and recharge

Air in systemRecover refrigerant, evacuate system, and re-charge

Outdoor coil dirty or restricted Clean coil or remove restriction

Excessive head pressure

Dirty air filter Replace filterDirty indoor or outdoor coil Clean coilRefrigerant overcharged Recover excess refrigerant

Air in systemRecover refrigerant, evacuate system, and re-charge

(Heat) Indoor air restricted or recirculating Determine cause and correctIndoor or outdoor air restricted or air short--cycling Determine cause and correct

Head pressure too lowLow refrigerant charge Check for leaks, repair and rechargeRestriction in liquid tube Remove restriction

Excessive suction pressure(Cool) High Heat load Check for source and eliminateReversing valve hung up or leaking internally Replace valveRefrigerant overcharged Recover excess refrigerant

Suction pressure too low

(Cool) Dirty air filter Replace filterLow refrigerant charge Check for leaks, repair and rechargeMetering device or low side restricted Remove source of restriction

(Cool) Insufficient coil airflowIncrease air quantityCheck filter–replace if necessary

(Cool) Temperature too low in conditioned area Reset UI setting(Cool) Outdoor ambient below 55°F (13_C) Verify low--ambient cooling enabled in UIFilter drier restricted Replace

IFM does not runBlower wheel not secured to shaft Properly tighten blower wheel to shaftInsufficient voltage at motor Determine cause and correctPower connectors not properly sealed Connectors should snap easily; do not force

IFM operation is intermittentWater dripping into motor Verify proper drip loops in connector wires

Connectors not firmly sealedGently pull wires individually to be sure they arecrimped into the housing

IFM--Indoor Fan Motor

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START--UP CHECKLIST(Remove and Store in Job Files)

I. PRELIMINARY INFORMATIONMODEL NO.:SERIAL NO.:DATE:TECHNICIAN:

II. PRESTART--UP (Insert check mark in box as each item is completed)( ) VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT( ) REMOVE ALL SHIPPING HOLD DOWN BOLTS AND BRACKETS PER INSTALLATION INSTRUCTIONS( ) CHECK ALL ELECTRICAL CONNECTIONS AND TERMINALS FOR TIGHTNESS( ) CHECK THAT INDOOR (EVAPORATOR) AIR FILTER IS CLEAN AND IN PLACE( ) VERIFY THAT UNIT INSTALLATION IS LEVEL( ) CHECK FAN WHEEL, AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE AND SETSCREW TIGHTNESS( ) MAKE SURE THAT -- (If Applicable) ON 60 SIZE PURON HEAT PUMP ONLY, THE TWO WIRE TIES FASTEN TO THE

OUTDOOR COILS AND REVERSING VALVE/ACCUMULATOR HAVE BEEN REMOVED

III. START--UPELECTRICALSUPPLY VOLTAGECOMPRESSOR AMPSINDOOR (EVAPORATOR) FAN AMPSTEMPERATURESOUTDOOR (CONDENSER) AIR TEMPERATURE DBRETURN--AIR TEMPERATURE DB WBCOOLING SUPPLY AIR DB WBHEAT PUMP SUPPLY AIR __________________ELECTRIC HEAT SUPPLY AIR_______________PRESSURESREFRIGERANT SUCTION PSIG, SUCTION LINE TEMP*REFRIGERANT DISCHARGE PSIG, LIQUID TEMP{( ) VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS( ) TEMPERATURE RISE (See Literature) RANGE _______________( ) MEASURED TEMPERATURE RISE ____________* Measured at suction inlet to compressor{ Measured at liquid line leaving condenser.

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Copyright 2009 Carrier Corp. D 7310 W. Morris St. D Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 03/09

Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.

Catalog No:50XT---03SI

Replaces: 50XT---02SI

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