Technical Catalogue-RUA-4AT3S to RUA10AT3S
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Transcript of Technical Catalogue-RUA-4AT3S to RUA10AT3S
HITACHI SELF-CONTAINED AIR CONDITIONERS
Technical Catalog ⅡⅡⅡⅡ
-Installation, Operation and Maintenance Instructions-
Models:
RUA-4AT3S
RUA-5AT3S
RUA-6AT3S
RUA-8AT3S
RUA-9AT3S
RUA-10AT3S
TU-TCⅡⅡⅡⅡ-11 (X4)
The standard utilization of the unit shall be explained
in these instructions. Therefore, the utilization of the
unit other than those indicated in these instructions is
not recommended. Please contact your local agent, as
the occasion arises.
HITACHI’s liability shall not cover defects arising from
the alternation performed by a customer without
HITACHI’s consent in a written form.
———— CONTENTS —
No. Item Page
Operation Instructions ............................................................... ⅠⅠⅠⅠ
1. PREPARATION......................................................................... 1
1.1 Initial Check ................................................................................................ 1
1.2 Transportation............................................................................................. 1
1.3 Placing the unit ........................................................................................... 2
2. INSTALLATION......................................................................... 3
2.1 Ducting Arrangement .................................................................................. 3
2.2 Condensate Drain Piping ............................................................................ 3
3. ELECTRICAL WIRING.............................................................. 4
3.1 Main Power Wiring Procedures................................................................... 4
3.2 Control Wiring ............................................................................................. 4
3.3 Printed Circuit Board (PCB) Layout ............................................................ 5
4. FAN SPEED ADJUSTMENT ..................................................... 7
5. REMOVING SHIPPING WASHERS .......................................... 8
6. TEST RUNNING ....................................................................... 9
6.1 Final Installation Check ............................................................................... 9
6.2 Preparation ................................................................................................. 9
6.3 Test Running............................................................................................... 9
6.4 Test Running Record ................................................................................ 10
6.5 Safety and Control Device Setting ............................................................ 13
7. MAINTENANCE .......................................................................14
8. WINTER SHUTDOWN .............................................................15
9. REPLACEMENT OF PARTS ...................................................15
10. TROUBLESHOOTING ...........................................................17
HITACHI SELF-CONTAINED AIR CONDITIONERS
OPERATION INSTRUCTIONS Models RUA-4AT3S, RUA-5AT3S, RUA-6AT3S, RUA-8AT3S, RUA-9AT3S and RUA-10AT3S
Starting Procedures
1. Switch ON the main power source to the unit.
2. Set the operation switch of the room thermostat
to the desired operation position.
FAN – Ventilation Operation
COOL – Cooling Operation
3. Set the thermostat knob of the room thermostat
to the desired temperature.
4. Set the system switch of the room thermostat to
the ON positions.
Stopping Procedures
1. Set the system switch to the OFF position.
2. Switch OFF the main power source to the unit.
Troubleshooting
Unit Does Not Start
1. Is the main power source switch to the unit ON?
2. Is the main fuse normal?
3. Is the phase of main power source right?
Poor Cooling Operation
1. Are there any obstacles, which hamper sufficient
air to the condenser?
2. Check to ensure that the thermostat is set at the
desired position.
3. Check the air filter for clogging.
4. Are there any obstacles, which hamper free air,
flow to the room thermostat?
Maintenance
1. Clean or replace the filter.
2. Clean the cabinet with cleaner.
3. Clean the condensate drain pan and the drain
piping.
4. Clean the condenser. It is recommended that a
specialist be contacted for this type of work.
5. Check for abnormal sounds and vibration. Stop
the unit and contact your service shop, if
observed.
Ⅰ
Please contact your service shop if the
trouble is still not solved
PREPARATION
1
1. PREPARATION
1.1 Initial Check
Required Materials - Measure, Architectural
Information Regarding Installation Location.
Installation Location - Confirm that the final
Installation location is provided with convenient
piping and wiring work. Strong water runoff
should be avoided.
Installation Space - Check for obstacles that
restrict condenser air flow or hamper maintenance
work in the space specified in Fig. 1.
Foundation - Check to ensure that the foundation
is flat, level and sufficiently strong, taking
into account the maximum foundation gradient
(Fig. 2) and the unit weight balance. Confirm
elevation provision for the unit on a solid base with
an iron frame or concrete curbs shown in Fig. 3,
In order to obtain proper clearance beneath the
unit for either rooftop or on-the-ground
installation. Additionally, for on-the-ground
installation, provide a gravel or concrete space
around the condenser air intake, in order to avoid
airflow obstruction due to grass or other
vegetation.
Unit - Check to ensure that the unit has been
transported without damage. File a damage claim
with the transportation companies if mishandling
due to transportation company negligence is
suspected.
1.2 Transportation Secure the route to the final installation location
by confirming the packing dimensions (see "Unit
General Data" in Technical Catalog I).
(mm)
Unit Dimensions Minimum Maintenance Space Minimum Air Intake Space
Maximum Height of
Wall Model
a b h A B C D E H
RUA-4AT3S 1,020 1,435 630 1,000 1,000 1,000 1,200 1,000 630
RUA-5AT3S 1,020 1,435 630 1,000 1,000 1,000 1,200 1,000 630
RUA-6AT3S 1,020 1,435 730 1,000 1,000 1,000 1,200 1,000 730
RUA-8AT3S 1,020 1,635 730 1,000 1,000 1,000 1,425 1,000 730
RUA-9AT3S 1,020 1,635 900 1,000 1,000 1,000 1,425 1,000 900
RUA-10AT3S 1,020 1,635 900 1,000 1,000 1,000 1,425 1,000 900
Fig. 1. Operation Space
PREPARATION
2
Fig. 2. Foundation Gradient
Model Dimensions A(mm)
RUA-4AT3S 1,460
RUA-5AT3S 1,460
RUA-6AT3S 1,460
RUA-8AT3S 1,660
RUA-9AT3S 1,660
RUA-10AT3S 1,660
Fig. 3. Recommended Concrete Curbs
1.3 Placing the Unit
Tools and Instruments - Pincers, Wrenches,
Facilities to Transport and Place the Unit.
Transportation - Transport the unit as close to
the final installation location as practical before
unpacking is performed. Keep the unit upright.
When transporting the unit after unpacking has
been performed, take note of the following.
Rolling-Place three equal - sized rollers under
the base frames. Each roller must carry both of
the outer frames, and must be situated to
balance the unit (refer to the center of gravity in
Fig. 4).
Lifting by Forklift - Insert the forks under the
base frames from the indicated direction in
Fig.4. Lift the unit, exercising care to catch both
of the outer frames.
Rigging - Apply spreader bars to the top of the
unit, in order to prevent damage to the unit due
to cable scratches.
Unpacking - Follow the instructions marked on
the packing.
Dimensions
A B Model
deg. mm deg. mm
RUA-4AT3S 0.4 10 0.6 11
RUA-5AT3S 0.4 10 0.6 11
RUA-6AT3S 0.4 10 0.6 11
RUA-8AT3S 0.4 10 0.6 11
RUA-9AT3S 0.4 10 0.6 11
RUA-10AT3S 0.4 10 0.6 11
INSTALLATION
3
Dimensions(mm) Model
A B C D
Weight
(kg)
RUA-4AT3S 725 710 405 615 195
RUA-5AT3S 725 710 405 615 195
RUA-6AT3S 725 710 405 615 220
RUA-8AT3S 935 700 405 615 275
RUA-9AT3S 905 730 405 615 290
RUA-10AT3S 905 730 405 615 305
Fig. 4. Center of Gravity
2. INSTALLATION
2.1 Ducting Arrangement
Tools and Instruments - General Tools for
Ducting
Connection - Pre-drilled duct flanges are
provided at the supply and return air duct
connections. A field-supplied or optional filter
box with filter must be installed at a proper
location in the return air duct. It is
recommended that flexible duct connections be
installed to minimize sound and vibration
transmission. All ducts running outside must be
sufficiently insulated and weatherproofed.
2.2 Condensate Drain Piping
Tools and Instruments - General Piping Tools
Drain Trap - A female piping thread screw
connection is provided at side of the unit.
Dimension "L" in Fig. 5 should be sufficiently
longer than the negative fan pressure at the
drain connection (50mm to 100mm, depending
on the return air duct design). Always fill the
trap with water.
Fig. 5. Condensate Drain Connection
Unit
Larger than "L"
Larger than "1/2L"
Condensate Drain Connection
To Atmosphere
ELECTRICAL WIRING
4
3. ELECTRICAL WIRING
Tools and Instruments - One Set of Wiring
Tools, Electrical Tester (Clamp Meter)
Schedule Check - Confirm that the field
selected electrical components (main power
switch, fuses, wires, conduit connections, wire
terminals) are properly selected according to
"Electrical Data" in Technical Catalog Ⅰ , and
ensure that they comply with national and local
codes. It is recommended that the main power
switch be locked at the OFF position, to prevent
against accidental supply of the power during
unit servicing.
Service Panel - Access to the magnetic switch
box is provided from the service panel, which is
fixed with screws (see the panel location in the
Operation Instructions.)
3.1 Main Power Wiring Procedures Confirm that electrical power is not being
supplied to the installation location prior to any
electrical installation work.
1.Install the field-supplied main switch box at
the properly-selected location.
2.Install conduit connectors in the hole for
power wiring (knockout holes).
3.Lead the main power wires and the earthling
wire through the connector to the screw
terminals for main power and earthing in the
magnetic switch box. The neutral wire to
380V and 415V power supplies should also
be led through the connector. Firmly connect
the wires with wire terminals to the unit
screw terminals R(L1),S(L2) and T(L3) and
also Mp(N) for 380V and 415V power
supplies according to Fig. 6 or the wiring
label attached to the magnetic switch box.
A scroll compressor is equipped. Because that
the rotation direction of the orbiting scroll of the
HITACHI scroll type compressor is fixed,
therefore a reversal phase protection is
equipped in this unit. If each phase R,S or T of
the power source is incorrectly connected, the
compressor does not start due to the activation
of the reversal phase protection device.
Therefore, in order to check the correct wiring
connection, the utilization of a phase sequence
indicator is recommended when the unit is
started after installation of the unit.
(1) If the phase is wrong, exchange two of the
three wires connected from the main power
source to the main terminals of the unit as
indicated with dotted lines, and then check
the rotation direction of the phase
sequence indicator once again. Do not
exchange the wires in the unit in order to
protect the compressor against the reversal
rotation.
(2) Do not operate the compressor by depressing
the button of the magnetic switch for the
compressor.
A three-phase condenser fan motor is equipped,
therefore, the fan motor rotation should be
checked. Interchange two of the three main
power source wires, if incorrect rotation is
detected during initial start-up.
3.2 Control Wiring
Install the optional room thermostat at a
suitable location in the space to be
air-conditioned. Connect the control wires
between the unit terminals and the thermostat
terminals according to Fig. 6 or the wiring label.
If a locally-supplied thermostat and switch are
installed, connect the wiring according
Technical Catalog Ⅰ .
Fig. 6. Field Wiring Connection
Power Source
R
Unit Side
S T Mp
ELECTRICAL WIRING
5
3.3 Printed Circuit Board (PCB) Layout
3.3.1 PCB Drawing
The PCB in the Unit is operating with 3 types of DIP Switches. The location is as follows
3.3.2 Different Main Power Supply
When the main power supply is 380V (nominal voltage), be sure to change the wiring connected terminal from L to M as shown figure below
3.3.3 Setting of Dip Switch (DSW)
All DSW were set correctly at factory, do not change settings of DSW. Before setting DSW, firstly turn off
power source and set the position of the DSW. If the switches are set without turning off the power source,
the contents of to the setting are invalid. Mark of “ “ indicates the position of dip switch.
Mark Name of Parts Mark Name of Parts
CT1 Current Transformer for NO.1 Compressor DSW2 Dip Switch for Optional Function Setting (1)
CN6 Connector for Transformer Input DSW3 Dip Switch for Optional Function Setting (2)
CN7 Connector for Transformer Output L,M Terminal for Different Main Power Supply
DSW1 Dip Switch for Capacity Setting A,B,D,E,F Terminal for Room Thermostat
TSR MLN
17
FEDBA2 2119 2018
CT1
3213 41421 3 2IC1 / 7812
CN7
CN6
IC2 / 7805Flickers(Red Lamp)
0NDSW1
0N DIPDSW3 DSW2
DIP 0N DIP
Factory Setting Factory Setting 3
ON
1 2 3 4
ON
1 2
Dip Switch Setting
DSW2:Optional Function Settings (1)
Setting Position21 3
DSW1:Capacity Settings
Capacity 4HP
ON
Dip Switch Setting
10HP
DSW3:Optional Function Settings (2)
14 3 42 31 2 4
5HP
ON
6HP
ON
24321 1 43 321
9HP8HP
ON ON ON
4
ELECTRICAL WIRING
6
3.3.4 Alarm Detect Functions
If the system is operated under abnormal conditions. during the test running or in normal operate. the red
lamp of the PCB flickers. The states of red lamp flickers are Indicated in Following Table
State of Red Lamp Flickers
Description Check Item
Continue Light Normal —
Once Reverse or Single Phase of Main Power Source
1)Check the connection of main power supply. (Refer to 3.1 Main Power Wiring Procedures)
Twice Incorrect Wiring Connection of Room Thermostat
1)Check wiring and connections between unit and thermostat. (Refer to 3. 2 Control Wiring)
3 Times Trip Detected of Safety Device
1)Check the current for indoor fan motor.
2)Check the current for outdoor fan motor.
3)Check the pressure of discharge and suction line.(Refer to 10. Troubleshooting)
4)Check the internal thermostat of compressor.
4 Times Overcurrent of Compressor
1)Check the current for compressor motor.
2)Check the pressure of discharge and suction line.(Refer to 10. Troubleshooting)
3)Check the resistance of current transformer by tester.(Refer to Wiring nameplate)
5 Times Detect of Power Off 1)Check the main power supply.
6 Times Wrong Detect of CPU 1)The CPU of PCB self-checking.
(No need to check the item of unit)
7 Times No Capacity Setting of Unit 1)Check the setting of DSW1 switch.
(Refer to 3.3.3 Setting of Dip Switch)
Notes:
1) The Red Lamp Flickers cycle will continue showing at intervals of 3 seconds until the Indication problem be solved.
2) If unit still under abnormal conditions, please contact your distributor.
FAN SPEED ADJUSTMENT
7
4. FAN SPEED ADJUSTMENT RUA-4AT3S and RUA-5AT3S
Directly driven fan–The unit is equipped with a
directly driven fan motor. The fan speed can be
varied through wiring change of fan motor.
(refer to Table 1 and Fig. 7)
RUA-6AT3S, RUA-8AT3S, RUA-9AT3S and
RUA-10AT3S
Belt driven fan–The unit is equipped with an
adjustable motor pulley. The fan speed can be
varied through a given range by adjustment of
the pulley. Table 2. Shows the setting speed and
the variable speed range. To change the speed,
adjust the motor pulley as follows (refer to Fig. 8).
1.Loosen the two bolts on the adjusting bracket for the fan belt tension and loosen the belt by
pushing the motor upward.
2.Loosen the setscrew in the movable pulley flange.
3.Turn the movable pulley flange toward the fixed flange to increase the speed, and turn it away from the fixed flange to decrease the speed. Each turn of the movable flange will increase or decrease the fan speed by 45 rpm.
4.Tighten the setscrew in the movable pulley, which is positioned over the flat surfaces of the fixed pulley.
5.Adjust the belt tension (approximately 20 mm deflection with one finger) by pushing the motor downward and tightening the bolts on the adjusting bracket.
X: Regulation Space of Motor Pulley PD: Pitch Diameter of Motor Pulley (mm)
Factory Set point
x 0 1 2 3 4 5 6 7 Model
PD 112 109 106 103 99 96 93 90 x RPM PD
RPM /
Turn
RUA-6AT3S RPM 1,030 1,010 980 950 910 880 860 830 5 880 96 45
RUA-8AT3S RPM 1,120 1,090 1,060 1,025 995 960 930 900 7 900 90 45
RUA-9AT3S RPM 1,120 1,090 1,060 1,025 995 960 930 900 5.6 950 95 45
RUA-10AT3S RPM 1,120 1,090 1,060 1,025 995 960 930 900 4.1 990 99 45
RPM: Fan Speed (RPM)
PD: Pitch Diameter of Motor Pulley (mm)
RPM/Turn: Fan Speed Change per One Turn of Movable Motor Pulley Flange (RPM/Turn)
Table 2. Fan Speed Adjustment
Fig. 8. Adjustable Motor Pulley Fig. 7. Wiring for changeable of Fan Speed
Table 1. Fan Speed Adjustment
REMOVING SHIPPING WASHERS
8
5. REMOVING SHIPPING WASHERS
RUA-4AT3S, RUA-5AT3S and RUA-6AT3S-The compressors are mounted on rubber isolators, and are
held rigid during shipment by two sets of shipping washers (refer to Fig. 9-1). Before compressor starting,
remove the yellow-painted shipping washers, the compressor should float freely on the rubber isolators.
Fig. 9-1. For Models RUA-4AT3S, RUA-5AT3S and RUA-6AT3S
RUA-8AT3S , RUA-9AT3S and RUA-10AT3S-The compressors are mounted on rubber isolators, there are
not shipping washers (refer to Fig. 9-2).
Fig. 9-2. For Models RUA-8AT3S, RUA-9AT3S and RUA-10AT3S
Nut
(Yellow Painted)
Shipping Washer Stud Bolt
Compressor Frame
Rubber Isolator 1
Base
Rubber Isolator 2
Base
Rubber Isolator 1
Compressor Frame
Rubber Isolator 2
Stud Bolt
Nut
Washer
TEST RUNNING
9
6. TEST RUNNING 6.1 Final Installation Check
Inspect the installation work according to all documents and drawings. Table 3. Shows the minimum check points.
Table 3. Installation Check List
6.2 Preparation
Tools and Instruments - High and Low
Pressure Compound Gauge(s), An Electric
Tester, General Tools.
Preparation - Confirm that the system switch on
the room thermostat is at the OFF position.
Pressure Gauges - Equip high and low pressure
compound gauges according to Fig. 12.
Thermostat - Set the thermostat at a lower
temperature than the room temperature.
6.3 Test Running
Test running should be performed as follows,
when the unit is wired according to the HITACHI
standard wiring label.
1.Set the operation switch to the FAN position
and the system switch to the ON position, and
the evaporator fan will start immediately.
Check the rotation direction, fan speed and air
flow quantity through the evaporator.
2.Set the operation switch to the COOL position,
and the compressor and condenser fans will start
3 minutes after this operation (refer to Fig. 10).
3.After system operation has become stabilized,
check the suction and discharge pressures on the
compound gauges. Normal operating pressures
are shown in Fig. 11.
4.Check the operating voltage, phase balance and
operating current.
5.Check to ensure that the thermostat functions
properly.
6.Check to ensure that the control and protective
devices function properly (refer to Table 4).
INSTALLATION WORK CHECK LIST
1.Is the unit solidly mounted and leveled?
2.Is the installation location adequate?
Space for Condenser Air Flow
Space for Maintenance Work
Noise and Vibration
Sunshine and Rainfall
Appearance
3.Is the ducting work adequate?
Filter Soundproofing
Size and Length Insulation
4.Are the condensate drain lines properly arranged?
Trap Drain Ditch
5.Is the electrical wiring system adequate?
Wire Size Tightened Connections
Switch Size Operation Control Devices
Fuse Size Safety Devices
Voltage Hz
TEST RUNNING
10
6.4 Test Running Record
Compile test running records according to Table 3. Utilize these records for periodic operation checks, as well as for troubleshooting.
Operational Sequence Chart �: ON �: OFF
*Main Power Switch OFF ON
FAN AUTO ON AUTO
COOL OFF ON
Operation
Equipments *Room Thermostat
TH ─ ─ ─ � � � �
Indoor Fan Motor MIF � � � � � � �
Outdoor Fan Motor MOF � � � � � � � Electric
Components Compressor MC � � � � � � �
Safety Devices Close Close Close Close Close Close Open
Fig. 10. Standard Operation Sequence
NOTES: 1. *: Field Supplied.
After 3 min.
TEST RUNNING
11
Fig. 11-1. Nominal Operation Pressures
for RUA-4AT3S
Fig. 11-3. Nominal Operation Pressures
for RUA-6AT3S
Fig. 11-2. Nominal Operation Pressures
for RUA-5AT3S
Fig. 11-4. Nominal Operation Pressures
for RUA-8AT3S
TEST RUNNING
12
Fig. 11-5. Nominal Operation Pressures for RUA-9T3S
Fig. 11-6. Nominal Operation Pressures for RUA-10AT3S
TEST RUNNING
13
6.5 Safety and Control Device Setting
Table 4. Safety and Control Device Setting
Models RUA-4AT3S RUA-5AT3S RUA-6AT3S RUA-8AT3S RUA-9AT3S RUA-10AT3S
For Compressor 400DH 500DH 600DH 750EL 900EL 1000EL
High Pressure Switch Automatic Reset, Non-Adjustable
Cut-Out
Cut-In
kg/cm2G
kPa
kg/cm2G
kPa
30.0
2,940
24.0
2,350
30.0
2,940
24.0
2,350
30.0
2,940
24.0
2,350
30.0
2,940
24.0
2,350
30.0
2940
24.0
2350
30.0
2,940
24.0
2,350
Overcurrent Transformer Automatic Reset, Non-Adjustable
Cut-Out
A 13.2 16.8 19.8 24.2 28.5 31.5
For Compressor Motor
Automatic Reset, Non-Adjustable
Internal Thermostat
Cut-Out
Cut-In
°C
°C
135
113
135
113
135
113
135
113
135
113
135
113
CCP Timer for Compressor Non-Adjustable
(Building on PCB)
min. 3 3 3 3 3 3
Manual Reset, Adjustable For Evaporator Fan Motor
Overcurrent Relay
A 3.3 4.4 2.1 2.1 3.6 3.6
Automatic Reset, Non-Adjustable Internal Thermostat
Cut-Out
Cut-In
°C
°C
130
100
130
100
—
—
—
—
—
—
—
—
Automatic Reset, Non-Adjustable
For Condenser Fan Motor
Internal Thermostat
Cut-Out
Cut-In
°C
°C
160
130
160
130
160
130
160
130
160
130
160
130
For Control Circuit Fuse
Capacity
A
2.5
2.5
2.5
2.5
2.5
2.5
MAINTENANCE
14
7. MAINTENANCE The unit should be periodically inspected
according to the same items as those described in
the paragraph entitled "Test Running". In order to
ensure dependable operation and long life, the
following additional items should be given
particular attention.
Components
Compressor - No maintenance work is required
for hermetic compressors, if the cycle remains
sealed.
Air-Cooled Condenser - Inspect the condenser
and remove any accumulated dirt from the coil at
regular intervals. Other obstacles such as growing
grass and pieces of paper, which might restrict air
flow, should also be removed.
Electrical Equipment - Always pay careful
attention to working voltage, amperage and phase
balance. Check for faulty contact caused by
loosened terminal connections, oxidized contacts,
foreign matter and others.
Control and Protective Devices - Do not readjust
the setting in the field unless the setting is
maintained at a point other than the point listed in
Table 4.
Field-Supplied Filter - Inspect for accumulated
dirt on the filter. Exchange or clean the filter if
required. The inspection interval may be
determined by the operating conditions for each
installation site.
Condensate Drain Pan and Drain Line – Inspect
and/or clean the condensate drain line at least
twice a year.
Evaporator Fan - Check for a loosened fan belt
and abnormal sounds.
Lubrication
Compressor - The compressors are charged at
the factory with the correct oil listed in "Component
Detailed Data" in Technical Catalog Ⅰ and the
compressor nameplate. It is not necessary to add
oil, if the cycle remains sealed.
Fan Motors and Bearings - All fan motors and
the evaporator fan shaft bearings are
pre-lubricated. Lubrication is not required.
Refrigerant Cycle Strainer - Check for clogging after the time when
the cycle is opened.
Refrigerant Re-Charge - When the cycle requires
re-charging due to leakage or replacement of parts,
follow the procedures given below for two cases
(refer to Fig.12).
1.Connect a vacuum pump and a low-pressure
compound gauge to the high-pressure check
joint at the compressor discharge side, and
completely evacuate the cycle.
2.Connect a charging cylinder to the check joint
illustrated in the figure, and charge refrigerant in
the cycle by weighing the charging cylinder.
Proper refrigerant charge is specified on the unit
nameplate or given in the figure.
When Slight Leakage from the cycle Occurs –
Evacuation might not be required.
1.Connect a high-pressure compound gauge to
the high-pressure check joint.
2.Connect a charging cylinder and a low-pressure
compound gauge to the check joint illustrated in
the figure.
3.Operate the unit.
4.Slowly charge refrigerant vapor into the cycle,
until the pressure reach the points illustrated in
Fig. 12.
MAINTENANCE
15
Fig. 12. Refrigerant Re-Charge
Compressor Removal
When removing the compressor -
1.Shut OFF the power supply to the unit.
2.Remove all wiring connections and piping connections to the compressor.
3.Remove the bolts fastened on the compressor frame.
4.Upward lift and pull out the compressor.
8. WINTER SHUTDOWN Winter shutdown
When shutting down the unit for winter, clean the
inside and the outside of the cabinet and dry the
unit, especially the drain pan and the drain lines.
This unit shall be preferably covered during
shutdown, in order to protect it from dust and
environmental conditions.
Spring Start-Up
After any extended shutdown period, prepare the
unit for operation as follows.
1.Thoroughly inspect and clean the unit.
2.Clean or replace the air filters.
3.Clean the condensate drain lines.
4.Remove any accumulated dirt from the
condenser and the evaporator coil.
5.Check the fan balance and attempt to operate
the fan.
6.Check the fan belt tension.
7.Tighten all wiring connections and access
panels.
9. REPLACEMENT OF PARTS Ordering from the HITACHI Parts List should
perform replacement of parts. The Form A
HITACHI Recommended Spare Parts List is
advisable. When replacement of parts becomes
necessary, prepare the parts shown in the Form
A Parts List.
Do not charge OXYGEN,
ACETYLENE or other flammable and
poisonous gases into the refrigeration
cycle when performing a leakage test
or an airtight test. These types of
gases are extremely dangerous,
because explosion can occur. It is
recommended that compressed air,
nitrogen or refrigerant be charged
for these types of tests.
▲▲▲▲DANGER !!!!
Turn OFF all the switches before
servicing.
▲▲▲▲DANGER !!!!
Capillary Tube
Unit Piping
Check Joint for Low Pressure Cylinder
Field Piping
Charging
Evaporator
Check Joint for
High Pressure
Low
Vacuum Pump
High
Pressure Gauge
Compressor
Condenser Strainer
Refrigerant R-22(kg)
Model Operating Charge
RUA-4AT3S 2.2
RUA-5AT3S 2.6
RUA-6AT3S 3.5
RUA-8AT3S 4.2
RUA-9AT3S 4.7
RUA-10AT3S 4.8
MAINTENANCE
16
Table 5. Test Running and Maintenance Record
MODEL: RUA- MFG. NO. COMPRESSOR MFG. NO.:
CUSTOMER'S NAME AND ADDRESS: DATE:
1. Is the rotation direction of the evaporator fan correct?
2. Is the rotation direction of the condenser fan correct?
3. Are there any abnormal sounds?
4. Has the unit been operated at least twenty (20) minutes?
5. Check Room Temperatures:
Inlet: DB ℃,WB ℃
Outlet: DB ℃,WB ℃
6. Check ambient Temperatures:
Inlet: DB ℃,WB ℃
Outlet: DB ℃,WB ℃
7. Check suction line Temperature and superheat:
Suction line Temperature: ℃,
Superheat: ℃,
8. Check Pressures:
Discharge Pressure: kg/cm2G
Suction Pressure : kg/cm2G
9. Check Voltage:
Rated Voltage: V
Operation Voltage:R-S V,S-T V,T-R V
Starting Voltage: V,
Phase Imbalance: 1 – V/Vm =
10. Check Compressor input and running current:
Input: kW
Running Current: A
11. Do the control devices function properly?
12. Do the protective devices function correctly?
13. Is the refrigerant charge adequate?
14. Are the drain lines draining freely?
15. Are the air filters clean?
16. Are the evaporator coil and condenser tubes clean?
17. Are all cabinet panels fixed?
18. Are all cabinet panels free from rattling?
19. Has the unit been checked for refrigerant leakage ?
TROUBLESHOOTING
17
10.TROUBLESHOOTING Troubleshooting Charts
The following charts show efficient checking procedures for trouble.
Fault Check Cause No Brackets Remedy
No Cooling
---------------------------------- Obtain the Correct Voltage
---------------------------------- Repair the Power Line
---------------------------------- Repair or Replace the
Components
---------------------------------- Tighten the Connections
---------------------------------- Obtain the Correct Voltage
---------------------------------- Check the Power Supply
to the Motor
Repair When Required
---------------------------------- Replace the Bearing
---------------------------------- Adjust Belt Tension
---------------------------------- Check Fan Speed and the
Ducting System
---------------------------------- Replace the Contactor
---------------------------------- Repair the Contacts
---------------------------------- Repair or Replace the Switch
---------------------------------- Obtain Correct Voltage
---------------------------------- Check the Power Supply
to the Motor
Repair When Required
---------------------------------- Repair or Replace if Required
---------------------------------- Replace the Contactor
---------------------------------- Repair the Contacts
---------------------------------- Replace the Compressor
---------------------------------- Correct the Wiring
No Voltage or Low Voltage
Single-Phase
Shorted Components
Loose Connections
High Voltage or Low Voltage
Single-Phase or Phase Imbalance
Faulty Fan Bearing
Excessive Fan Belt Tension
Excessive Fan Load
Burned Coil
Faulty Contact
Defective Operation Switch
High Voltage or Low Voltage
Single-Phase or Phase Imbalance
Burned Coil
Faulty Contact
Other Faulty Electrical Components
Open Compressor Windings
Incorrect Wiring
Faulty Unit Power Supply
Blown Fuses for Operation
Circuit
Tripped Overcurrent Relay
for Evaporator Fan
Tripped
Evaporator Fan
Motor Contactor
Faulty
Internal Thermostat
for Condenser Fan
Compressor
Contactor
Evaporator
Fan Motor
Stopped
Operating
Condenser
Fan Motor
Stopped
Operating
No Cooling (Compressor Does Not Start)
Faulty
TROUBLESHOOTING
18
Insufficient Cooling
----------------------------See ”High Discharge Pressure” or
”Low Suction Pressure”
----------------------------Repair the Clogging and
Replace the Switch if Required
----------------------------Repair or Replace if required
----------------------------Obtain Correct Voltage
----------------------------Check the Power Line to the
Compressor: Repair when Required
----------------------------See ”High Discharge Pressure” and
”High Suction Pressure”
----------------------------Tighten the Connections
----------------------------See ”High Suction Pressure”
----------------------------See ”High Discharge Pressure” or
”Low Suction Pressure”
High Discharge Pressure
-----------------------------Clean the Condenser
-----------------------------Check the Voltage and Obtain Correct Voltage
-----------------------------Repair or Replace the Motor
-----------------------------Secure Space for the Required Air Flow
-----------------------------Charge the Correct Refrigerant Quantity
-----------------------------Purge the Gas
-----------------------------Remove the Restriction
-----------------------------See ”High Suction Pressure”
Low Discharge Pressure
-----------------------------Add Refrigerant
-----------------------------See ”Unit Working Range”
Operating High Discharge Pressure or
Low Suction Pressure
Clogged Capillary of Pressure Switch High or Low
Pressure Switch
Tripped Overcurrent Relay
for Compressor
Compressor Cycling
Insufficient Cooling
High Discharge Pressure and
High Suction Pressure
Loose Connections
High Suction Pressure
High Discharge Pressure or
Low Suction Pressure
Tripped
High Voltage or Low Voltage
Single Phase or Phase Imbalance
Cycling ON
Faulty Switch
Condenser
Air Flow
High Discharge Pressure
Restricted
Clogged Condenser Coil
Low Fan Speed
Faulty Fan Motor
Circulating Air Flow
Overcharged Refrigerant
Non-Condensable Gas
Restricted Liquid Line
High Suction Pressure
Condenser Air
Inlet Temperature
High
Condenser
Air Flow
Low Discharge Pressure
Low Refrigerant Charge
Low Ambient Temperature
TROUBLESHOOTING
19
High Suction Pressure
-----------------------------Reduce the Fresh Air Intake
-----------------------------Reinforce the Duct Insulation
-----------------------------Replace or Repair the Compressor
-----------------------------Charge Correct Refrigerant Quantity
-----------------------------See ”High Discharge Pressure”
Low Suction Pressure
-----------------------------Clean the Air Filter
-----------------------------Adjust the Belt Tension
-----------------------------Remove the Restriction
-----------------------------Adjust the Fan Speed
-----------------------------Repair or Replace the Motor
-----------------------------Remove Obstacles to Air Circulation
-----------------------------Repair or Replace if Required
-----------------------------Remove the Restriction
-----------------------------Add Refrigerant
-----------------------------See ”Low Discharge Pressure”
Noisy Operation
----------Remove the Bolt(s)
----------Charge the Correct Refrigerant Quantity
----------See ”Low Suction Pressure”
----------Replace or Repair the Compressor
----------Fix the Runner or Casing Properly
----------Replace the Bearing
----------Adjust Fan Belt Tension
----------Clean the Strainer
----------Add Refrigerant
----------Tighten All Fixed Screws
----------See the Installation Guide
----------Clean the Flexible Ducts
Evaporator Air
Inlet Temperature
High Suction Pressure
High Excessive Fresh Air Intake
Insufficient Duct Insulation
Defective Compressor Valve
Overcharged Refrigerant
High Discharge Pressure
Evaporator
Air Flow
Low Suction Pressure
Restricted
Clogged Air Filter
Slipping Fan Belt
Restricted Duct
Low Fan Speed
Faulty Fan Motor
Short Cycling
Faulty Thermostat
Restricted Liquid Line and Suction Line
Low Refrigerant Charge
Evaporator Air
Inlet Temperature
Low
Low Discharge Pressure
Noisy Compressor
Noisy Operation
Low Suction Pressure
Worn Compressor Parts
Knocking Runner
Worn Bearing
Loose Fan Belt
Partially Clogged
Refrigerant Short Charge
Loose Fixed Screw
Weak Foundation Installation
Liquid Line Whistling
Inadequate Duct Work
Evaporator Fan
Unremoved Shipping Bolt(s)
Overcharged Refrigerant
Shipping Bolt(s) Noisy
Strainer
Liquid Refrigerant
Backing up
Noisy
Specifications in this catalog are subject to change without notice, in order that HITACHI may bring the latest innovations to our customers.
Catalog No. TU-TCⅡ-11 Printed in Taiwan