The ALCO Controls EC3-75x

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EC3-75x Series

Condenser Controller

Technical Data

EC37_35043_EN_R06.doc 1 / 8 30.05.2007

The ALCO Controls EC3-75x Series are electronic controllersfor air cooled condensers, typically used in supermarketrefrigeration applications. The control can take place in 6 steps,one of them with continous control output. Each step canactivate one single speed fan or a group of single speed fans.The control target is to maintain the condensing pressure at adefined value by varying the available fan capacity. Foroptimising energy efficiency of the total system, thiscondensing pressure can also be defined as a floatingminimum value. Other features include alarm management andheat recovery control.

The major advantage of the controllers is the built-in networkinterface, which is available in two options: Echelon LONnetwork or TCP/IP Ethernet. The TCP/IP version is ratherused in smaller applications where interaction of variouscontrollers with each others is not required. The LON-basedcontrollers provide full networking capabilities. This includesinteraction with other system components, such as compressorracks or monitoring systems, and integration into higher levelsystems, e.g. building management systems.

The EC3-75x Series is part of ALCOs complete solution forelectronic supermarket controllers which comprise racks, coldroom, display case controllers and remote monitoring systems.A full overview of the complete system offering is given in theElectronics System Overview Data Sheet.

Features EC3-75x Series controller

Condensing pressure control in up to 6 steps plus onecontinous speed control

Dead band, P/PI, base load control option

1 analog output signal for speed control Fan rotation rotation and run-time balancing

Setpoint shift and floating condensing pressure function

Heat recovery control

Maintenance and alarm management

Fast recovery from high and low condensing pressures

Sensor failure handling

Separate serial safety loop for each step

Input for common high pressure alarm

Configuration data stored in non-volatile memory

Aluminium enclosure for DIN-rail mounting

Electrical connection via plug-in type screw terminals

Supports two network interfaces:

Echelon LON-protocol for full network capabilities(FTT10) or TCP/IP Ethernet webserver function

Operation and commissioning via local or remote PC

Approval

EC3-75x Condenser Controllerwith ECD-000 Display Unit

Features ECD Display unit Connection via RJ45 Western digital plug, no further power

cables required

Easy mounting in panels with 71 x 29 mm cut-out

IP65 if mounted in front panel

Indicator LEDs for compressor and alarm status

Typical ordering package

Condenser controller EC3-75x

Terminal kit EC3-750

Display ECD-000

Display connector cable ECC-Nxx

Transformer ECT-623

Sensors for Temperature ECN-xxx

Selection

TCP/IP Ethernet LON, FTT10

Description Type Order No. Type Order No.

Condenser Controller for up to 6 stages, one with continous control

output 010V, heat recovery control

EC3-752 807 592 EC3-751 807 591


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Introduction

In air cooled condensers, fans are arranged to provide therequired cooling capacity. Typically, these condensers are usedin combination with compressor racks in supermarketrefrigeration applications. In such systems, the primary task of acondenser controller is the control of air flow in such a way thatthe condensing pressure is maintained at a defined level, wherethis defined level depends on overall system design. Inrefrigeration systems using electronic expansion valves to feedthe evaporator, it is desirable to define the target condensingpressure as a floating value, as low as ambient air temperatureallows, in order to optimise the refrigeration system for energyefficiency. Without electronic expansion valves, the condensingpressure must be kept at a minimum value, determined by thecapabilities of thermo expansion valves. In systems using heatrecovery, the condensing pressure must be kept artificially high.

Condenser capacity may be varied simply by cycling fans or byvarying fan speed through a TRIAC or by using an inverter.Besides of this main function of maintaining a condensingpressure level, condenser controllers accomplish othermanagement tasks which are related to system reliability,maintenance and system operating costs. Especially theselatter aspects can only be achieved efficiently by providing fullnetworking capabilities. The EC3-75x Series of condensercontrollers provides all these functions.

ApplicationsEC3-75x Series controllers are designed to control up to 6stages on a single control circuit of which the first stage may bespeed controlled by using the integrated 010V output signal.

Inputs1 = Ambient temperature2 = Humidity Sensor3 = Condensing pressure4 = Serial alarm inputs for up to 6 fans5 = High pressure alarm6 = Heat recovery demandOutputs

7 = For up to 6 stages, from which 1 can be speed controlled8 = Speed controlled fan (see 7)9= Heat recovery solenoid

The main control parameter is provided by a condensingpressure sensor which is wired directly to the controller. ALCO

PT4 pressure transmitters should be used for optimalperformance.

Control functions

The EC3-75x Series provides two basic fan control algorithms:dead bandand P/PIcontrol.Dead band control adds/removes fan capacity if thecondensing pressure is outside the defined dead band.

excess dead band demand

+-

setpoint Condensing Pressure

P/PI control distributes fan capacity evenly over theproportional band. Fan capacity is added/removed dependingon the deviation from the setpoint inside the proportional band.An optional integral portion may be specified for even moreaccurate control of the condensing pressure.

P1

0%

100%

P0 Condensing Pressure

A fan speed controller (e.g. the FSP series from ALCOControls) can be used in combination with dead band or P/PIcontrol. For this purpose, the software assigns the first fan ofthe board to a 010V output. Inverter control can reducevariations in condensing pressure and normally results in asmoother transition between capacity steps.

The configurable FIFO (First In First Out) logic manages fansin such a way that runtimes of all fans are balanced. Invertercontrolled fans and base load fans are, of course, excludedfrom this procedure.

Other control features include delay times for adding/ removingcapacity and minimum/maximum running times.

Target of the control process is the condensing pressure. Theactual condensing pressure is measured by means of apressure sensor. This is then compared with the condensingsetpoint. Setpoint options include temperature compensationby an external ambient sensor. Depending on ambienttemperature, the condensing pressure setpoint may be loweredin a controlled way resulting in a reduction of energyconsumption of the overall system. A fast recovery procedurecan be used to immediately switch off all fans when thecondensing pressure falls below a defined limit. Similarly anemergency routine can be activated automatically if thecondensing pressure exceeds a definable limit.

Heat recoveryEC3-75x Series condenser controllers support refrigerationsystems using heat recovery. For this purpose a secondsetpoint is provided which can be used to raise the targetcondensing pressure to the level needed for heat recoveryoperation. In order to switch over to heat recovery mode adigital input contact heat recovery demand is provided. Thesignal to request heat recovery operation is normally providedby an external thermostat. When received, the secondarysetpoint and a digital output relay are activated. This outputrelay is called heat recovery solenoid and can be used tocontrol a three-way-valve in order to switch the refrigerant sideof the condenser over to heat recovery operation.

Alarm/maintenance functionsEC3 provides several levels of alarm management. Limitviolation alarms are associated with the condensing pressuresetpoint. Maintenance alarms are based on fan runtimes.


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When a defined runtime is exceeded the maintenance alarm istriggered.

Serial alarms are based on Ditigal Input Contacts which areassociated with a certain fan. The serial alarm loop includes

control and monitoring components, such as motor overloadprotection devices, which are associated with a particular fan.This way a failure of a particular fan can be tracked and systemcontrol can continue by using the other fans which are not inalarm state.

AGeneral hp alarm input is provided for the connection of ahigh pressure switch. Triggering a general hp will cause the fanto be switched off immediately.

Alarm management includes the issuing of an alarm messagethrough the network and the display of an alarm code on theECD-000 display, if present. The priorities and subsequentactions can be defined for each alarm individually on the AMSMonitoring Server or for TCP/IP on the Webserver homepage.

Other maintenance features include manual operation, offsetcalibration for sensors and the possibility to exclude certaindevices from the control procedure.

Operation and Commissioning

Operating and commissioning of an EC3 controller may beperformed by using one of the following options:

- locally via the ECD Display with or without a remote control

- locally via standard PC connected to the EC3-xx2 withTCP/IP interface or

via AMS Monitoring Server / spezialized PC connected tothe EC3-xx1 with LON interface

- remotely by computer via public network (e.g. Internet) orVPN

For initial commissioning of a new installation the secondoptions are the most appropriate. Commissioning is done viadedicated menus, which make commissioning an EC3 a plug-and-play type of job and appears intuitive to anyone who isfamiliar with Microsoft Windows based programs.

Optional ECD Display Unit

The ECD may be attached to the EC3 Series Controller toprovide a local display of system parameters. Indicator LEDsshow the status of compressor, fan and alarm. A blinkingdisplay indicates that the EC3 Controller is in alarm.

WebServer function of the EC3-752 with TCP/IP Ethernetnetworking capabilities

Though the actual status of the controllers can be viewed on theoptional ECD Display Unit, it is much more convenient to do theviewing on a PC. All relevant parameters and modes are visibleon a single WebPage simultaneously. For even more detailsand for setup and maintenance a click on one of the screen tabscalls up a WebPage dedicated to specific task. All of this can bedone with a standard WebBrowser like the Internet Explorer,the Mozilla Firefox or others. The picture on page 4 shows thehomepage of an EC3-752 with the Monitoring WebPage of thecontroller.

Echelon LON Networking Capabilities of the EC3-751

The remote access, viewing and monitoring features of theLON version EC3 Series Controllers match and exceed thecapabilities of their TCP/IP counterparts. Though remote accessrequires the use of the Alco Controls AMS Monitoring Server or

special third party LON compliant hardware and software,many more additional functions and features are available.

The EC3-xx1 Controllers are equipped with LON-FTT10 (freetopology) transceiver types. This offers the installer greatest

flexibility in the way the controllers are connected to the LON

network in addition to offering higher communicationtransmission rates and reliability.

When connected to the LON network, the individual EC3Series controllers may be bound together through peer-to-peercommunication to form self-contained control loops forapplications such as synchronised defrosting.

Retrieval and download of setups and data is very comfortableand easily achievable in LON systems.

Refer to the "Alco Networking Application" sheets for furtherdetails.

Where to apply TCP/IP Ethernet vs. LON Controllers

In general TCP/IP Ethernet controllers are more applicable for

smaller refrigeration systems with only a few pieces ofrefrigeration equipment. No special hardware or specialsoftware is needed and whoever can set up a small PC networkhas all the necessary know-how to set up and operate EC2 andEC3 TCP/IP Ethernet controllers.

In larger installations LON has its merits. Network wiring iseasier and less costly. Peer-to-peer communication is anotherbenefit of LON and data retrieval and storage are very easilyachievable. These advantages come at a price however: amonitoring and server device like the Alco Controls AMS isneeded along with some special know-how in LONtechnology. The associated cost therefore makes LONtechnology primarily applicable in large refrigeration plants withmany pieces of refrigeration equipment like Supermarkets or

large cold storage facilities.


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Example WebPage for TCP/IP versionsFollowing picture shows the homepage monitoring screen of anEC3-752, with the ambient humidity and temperature on the left,condensing pressure readout and setpoint together with the

equivalent temperature on the right. In the field below are allcondenser controller status messages in normal font, all activemessages are printed bold in blue colour.

The lower right side shows the active stages and the opening ofthe analogue output.

A graph with the condensing pressure changes of a 10 Min.time interval can be displayed in the monitor screen.

A logfile can be stored on the PC. The file format of the datalogis text with semicolon (;) separated fields.

All screens which allow to change controller parameters arepassword protected.

While the 2 digit controller display indicates alarms assymbols which toogle between specified display, the alarmmonitoring screen shows all alarms in text form. The screenshows all possible alarm messages, while an active alarm ishighlighted with bold characters and in red colour.

Refer to the "TCP/IP-Controller-Readme" file for further details.

.


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Accessories

Description Type Order No. Description Type Order No.

Display

for front door mounting

ECD-000 807 640 Terminal kit (screw type)

Connector cable EC3 - ECD

RJ45-RJ45 1.0m

3.0m

5.0m

ECC-N10

ECC-N30

ECC-N50

807 860

807 861

807 862

for EC3-75x K03-750 807 654

Pressure transmitter PT4for pressure sensing

-0.8 7 bar, 4 20 mA PT4-07S 802 320

NTC sensor ECN singleinsulated

for ambient temperaturesensing 5050 C

0 18 bar, 4 20 mA PT4-18S 802 322 10 k at 25C, 1.5m ECN-S15 804 304

0 30 bar 4 20 mA

0 50 bar 4 20 mA

PT4-30S

PT4-50S

802 324

802 32610 k at 25C, 3.0m

10 k at 25C, 6.0m

ECN-S30

ECN-S60

804 305

804 284

Cable Assembly -50 +80C

Length 1,5m

Length 3,0m

Length 6,0m

PT4-L15

PT4-L30

PT4-L60

804 593

804 594

804 595

NTC sensor ECN singleinsulated

for discharge temperaturesensing 50 150C

1 M at 25C, 6.0m ECN-H60 804 359

TransformerDIN rail mounting, Class II,230V AC / 24V, 50VA

ECT-623 804 421


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Technical data

Controller EC3-75x Display ECD-000

Power supply 24VAC 10%; 50/60 Hz; Class II Power supply via ECC-Nxx from EC3 controller

Power consumption 20VA max. Display Numeric segmental display,LED red, 2 digits, numeric value,device status and alarm indication

LEDs 1 x Unit indicator bar / C1 x Alarm LED

TerminalsDigital I/OsAnalog I/O

Removable screw terminalswire size 0.5 2.5mm2

wire size 0.14 1.5mm2

Operating keys 4 operating keysProgramming, Select,Service/Up, Down

Communication TCP/IP Ethernet or LON FTT10 Connecting lead 1.5m / 3.0m / 5.0m (ECC-Nxx)

Temperaturestorageoperating

-20 +65C0 +60C

Temperaturestorageoperating

-20 +65C0 +60C

Humidity 0 80% r.h. non condensing Humidity 0 80% r.h. non condensing

Protection class IP20 Protection class IP 65 (front protection with gasket)Weight ~ 810 g Weight ~ 52gMounting DIN-rail mount Mounting Panel mount (71x29mm cut out)

Input and output configuration

Description I/O Specification EC3-75x

Pressure sensor input 24V DC, 4 20 mA 1

Fan output relais

Inductive (AC15) 250V / 2A

6

Heat recovery solenoid Heating (AC1) 250V / 8A 1

Spare output relay

Fan variable output signalCan be used in combination with the first output relayonly

0 10 V 1

Serial alarm inputs for fans Digital input contacts, 24 V AC/DC or 230 V AC,two input voltage ratings provided

6

Alarm input for hp switchHeat recovery demand input

Digital input contacts, 24 V AC/DC or 230 V AC,two input voltage ratings provided

11

External ambient temperature 10 k @ 25 C, -50 50 C 1


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Physical dimensions, drawings

EC3-75x Series controller housing

ECD-000 Display

ECT-623 Transformer

7562

50 62 71

82


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ALCO CONTROLS is not to be held responsible for erroneous literatureregarding capacities, dimensions, applications, etc. stated herein.Products, specifications and data in this literature are subject to change

without notice. The information given herein is based on technical dataand tests which ALCO CONTROLS believes to be reliable and whichare in compliance with technical knowledge of today. It is intended only

for use by persons having the appropriate technical knowledge andskills, at their own discretion and risk. Since conditions of use areoutside of ALCO'S control we can not assume any liability for resultsobtained or damages occurred due to improper application.

This document replaces all earlier versions.

Emerson Electric GmbH & Co. OHG

ALCO CONTROLS

Heerstrae 111

D-71332 Waiblingen

Germany

Phone ...49-(0)7151-509-0

Fax ...49-(0)7151-509-200

www.eCopeland.com/alcoliterature.cfm

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France, Greece, Maghreb

Deutschland, sterreich, Schweiz

Italia

Middle East & Africa

Poland

Russia & Cis

Espaa & Portugal

Sweden & Norway

UK & Ireland

Phone.:

+31 (0)773 240 234

+32 (0)87 305 565

+32 (0)87 305 061

+33 (0)478 668 570

+49 (0)6109 6059 0

+39 02 961 78 1

+97 148 832 828

+48 (0)22 458 9205

+7 495 981 9811

+34 93 4 123 752

+32 (0)87 305 565

+44 (0)1 635 876 161

Fax:

+31 (0)773 240 235

+49 24 08 929 568

+32 (0)87 305 506

+33 (0)478 668 571

+49 (0)6109 6059 40

+39 02 961 78 888

+97 148 832 848

+48 (0)22 458 9255

+7 495 981 9816

+34 93 4 124 215

+49 24 08 929 568

+44 (0)1 635 877 111

The ALCO Controls EC3-75x

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