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Emerson XW20K Installing And Operating Insructions

Download Installation reference manual of Emerson CX620 Temperature Controller for Free or View it Online on All-Guides.com. This version of Emerson CX620 Manual compatible with such list of devices, as: CX620, T620, T620T, V620, XW20K

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1592026000 XW20K GB R2.0 08.06.2011.doc XW60K 1/5

XW20K AND T620T - T620 – V620 – CX620

1 GENERAL WARNING ......................................................................................................... 1

2 GENERAL DESCRIPTION .................................................................................................. 1

3 CONTROLLING LOADS ...................................................................................................... 1

4 SPECIAL FUNCTIONS........................................................................................................ 1

5 KEYBOARDS...................................................................................................................... 1

6 AUTOMATIC KEYBOARD LOCK (ONLY FOR T620T) ......................................................... 2

7 CONTROLLER INTERFACE ............................................................................................... 2

8 PARAMETER LIST ............................................................................................................. 2

9 DIGITAL INPUT .................................................................................................................. 3

10 INSTALLATION AND MOUNTING ....................................................................................... 4

11 ELECTRICAL CONNECTIONS............................................................................................ 4

12 TTL/RS485 SERIAL LINE .................................................................................................... 4

13 HOW TO: USE OF THE PROGRAMMING “HOT KEY” ......................................................... 4

14 ALARM SIGNALS ............................................................................................................... 4

15 TECHNICAL DATA ............................................................................................................. 4

16 CONNECTIONS.................................................................................................................. 4

17 DEFAULT SETTING VALUES ............................................................................................. 5

1 GENERAL WARNING

1.1 PLEASE READ BEFORE USING THIS MANUAL

 This manual is part of the product and should be kept near the instrument for easy and quick

reference.

 The instrument shall not be used for purposes different from those described hereunder. It

cannot be used as a safety device.

 Check the application limits before proceeding.

1.2 SAFETY PRECAUTIONS

 Check the supply voltage is correct before connecting the instrument.

 Do not expose to water or moisture: use the controller only within the operating limits avoiding

sudden temperature changes with high atmospheric humidity to prevent formation of

condensation

 Warning: disconnect all electrical connections before any kind of maintenance.

 Fit the probe where it is not accessible by the End User. The instrument must not be opened.

 In case of failure or faulty operation send the instrument back to the distributor or to “Dixell S.r.l.”

(see address) with a detailed description of the fault.

 Consider the maximum current which can be applied to each relay (see Technical Data).

 Ensure that the wires for probes, loads and the power supply are separated and far enough from

each other, without crossing or intertwining.

 In case of applications in industrial environments, the use of mains filters (our mod. FT1) in

parallel with inductive loads could be useful.

2 GENERAL DESCRIPTION

Model XW20K is microprocessor based controller suitable for applications on normal or medium

temperature refrigerating units. It has to be connected by means of a two-wire cable ( 1mm) at a

distance of up to 30 meters to the keyboard T620T, T620, V620 or CX620.

It is provided with two relay outputs to control compressor and light. It is also provided with 3 NTC or

PTC probe inputs, one for temperature control, one to control the defrost end temperature of the

evaporator and the third to control condenser temperature or to display another temperature.

The HOT-KEY output allows to connect the unit, by means of the external module XJ485-CX, to a

network line ModBUS-RTU compatible such as a dIXEL monitoring units of X-WEB family. It allows

to program the controller by means the HOT-KEY programming keyboard.

The instrument is fully configurable through special parameters that can be easily programmed

through the keyboard.

3 CONTROLLING LOADS

3.1 THE COMPRESSOR

The regulation is performed according to the temperature measured by the thermostat probe with a

positive differential from the set point: if the temperature increases and reaches set point plus

differential the compressor is started and then turned off when the temperature reaches the set point

value again.

In case of fault in the thermostat probe the start and stop of the compressor are timed through

parameters Con and CoF.

The relay of the second compressor is activated in parallel with the relay of the first compressor, with a

possible delay set in the AC1 parameter. Both the compressors are switched off at the same time.

3.2 FAST FREEZING

When defrost is not in progress, it can be activated by holding the UP key pressed for about 3 sec.

The compressor operates to maintain the CCS set point for the time set through the CCt parameter.

The cycle can be terminated before the end of the set time using the same activation key UP for 3 sec.

3.3 DEFROST

Defrost is performed through a simple stop of the compressor. The parameters involved are: idF, to

control the interval between defrost cycles and MdF, which is the maximum defrost length. There are

also two defrost modes: timed or controlled by the evaporator’s probe (parameter dFP and P3P). At

the end of a defrost cycle a dripping time is started; its length is set in the FSt parameter. With FSt=0

the dripping time is disabled.

4 SPECIAL FUNCTIONS

By means of the parameter oA3, it’s possible to configure the functions of the light relay (22-23), as

described in the following paragraphs:

4.1 OA3 = LIG: LIGHT RELAY (FACTORY SETTING)

By setting oA3=Lig the relay will work as light relay, it is switched on and off by the light button on the

keyboard and is affected by status of the digital input when i1F=dor.

4.2 OA3 = CP2 SECOND COMPRESSOR MANAGEMENT

By setting oA3=CP2, the relay at terminals 22-23 will operate as “second compressor”. It will be

activated in parallel with the relay of the first compressor, with a possible delay set in the AC1

parameter (seconds). Both the compressors are switched off at the same time.

4.3 OA3 = ONF: ON –OFF RELAY

By setting oA3=onF, the relay will operate as “on-off” relay: it will be activated when the controller is

switched on and it will be switched off when the controller is in stand-by status.

4.4 OA3 = AUS: AUXILIARY RELAY

By setting oA3=AUS, the relay 22-23 will work as auxiliary thermostat (ex. anti condensing heater).

Parameters involved:

- ACH (cL, Ht): Kind of regulation for the auxiliary relay: Ht = heating / CL = cooling;

- SAA (-50÷150) Set point for auxiliary relay

- SHy (0÷25.5°C) Differential for auxiliary output.

With ACH = CL: aux relay cut in is SAA+SHy, cut out SAA.

With ACH = Ht: aux relay cut in is SAA-SHy, cut out SAA.

- ArP (nP, P1, P2, P3, P4) Probe for auxiliary relay

- Sdd (n, Y) Auxiliary output working during defrost

4.5 OA3 = ALR: ALARM RELAY

By setting oA3=ALr the relay will work as alarm relay, it is switched on when an alarm happens.

Parameters involved:

- tbA (n, y) Alarm relay silencing

- AoP (cL; oP) Alarm relay polarity

4.6 OA3 = DB: NEUTRAL ZONE

By setting oA3=db the controller will perform a

“neutral zone” regulation.

The heating element has to be connected to the

oA3 relay (22-23)

If the temperature increases and reaches set

point plus differential (HY) the compressor is

started and then turned off when the

temperature reaches the set point value again.

If the temperature decreases and reaches the

set point minus differential (HY) the oA3 output

(heater) is switched on and then turned OFF

when the temperature reaches again the set

point.

5 KEYBOARDS

T620T

T620

V620

CX620

To display and modify target set point; in programming mode it selects a parameter

or confirm an operation. By holding it pressed for 3 sec when max or min

temperature is displayed it will be erased.

To see the max stored temperature; in programming mode it browses the

parameter codes or increases the displayed value.

By holding it pressed for 3s the fast freezing cycle is started.

To see the min stored temperature; in programming mode it browses the parameter

codes or decreases the displayed value.