Danfoss EKC 368 User guide

Data sheet

Electronic media temperature controller Type EKC 368

The EKC 368 controller and KVS electric suction modulating valve are used where there are high requirements to refrigeration of unpacked food products, e.g.:

• Delicatessen appliances

• Cold rooms for meat products

• Cold rooms for fruits and vegetables

• Containers

• Air conditioning plant

Features y The temperature is kept within an accuracy of

±0.5°C or better after a transient phenomenon.

y A transient phenomenon can be controlled

with the adaptive function so that temperature variations is kept on a minimum.

y Defrost sensor, so that the defrost time will be

as short as pos sible.

y PID regulation.

DKRCC.PS.RP0.B1.02 / 520H9697

Manual Electronic media temperature controller, type EKC 368

Introduction

Application

Controller and valve are used where there are high requirements to refrigeration of unpacked food products, e.g.:

y Delicatessen appliances

y Cold rooms for meat products

y Cold rooms for fruits and vegetables

y Containers

y Air conditioning plant

System

A KVS valve is used. The capacity determines the size of it. A solenoid valve is mounted in the liquid line which is to close when the controller stops refrigeration. Sensor S evaporator.

Advantages

y Wastage is reduced because the air humidity around the pro-

y The temperature is kept within an accuracy of ±0.5°C or better

y A transient phenomenon can be controlled with the adaptive

y Defrost sensor, so that the defrost time will be as short as

y PID regulation

must be placed in the cold air current after the

air

ducts is kept as high as possible

after a transient phenomenon

function so that temperature variations is kept on a minimum

possible

Functions

y Modulating temperature control

y Defrost function: electricity, hotgas or natural

y Alarm if the set alarm limits are exceeded

y Relay outputs for defrost function, solenoid valve, fan and

alarmgiver

y Input signal that can displace the temperature reference

Extra options

y PC operation

The controller can be provided with data communication, so that it may be hooked up with other products in the ADAP-KOOL® range of refrigeration controls. Operation, monitoring and data collection can then be performed from a PC - either in situ or at a service company.

LED's on front panel

KVS - signal

Refrigeration

Fan

Defrost

2 DKRCC.PS.RP0.B1.02 / 520H9697 © Danfoss A/S (DCS-IMCGPD/sw), 2015-02

Manual Electronic media temperature controller, type EKC 368

Function

Very accurate temperature control

With this system where controller and valve have been adapted for optimum use in the refrigerating plant, the refrigerated products may be stored with temperature uctuations of less than ±0.5°C.

High air humidity

As the evaporating temperature is constantly adapted to the refrigeration needs and will always be as high as possible with very small temperature uctuations, the relative air humidity in the room will be kept at a maximum. Drying-out of products will therefore be reduced to a minimum.

Temperature is quickly attained

With the built-in PID control and the possibility of choosing between three transient phenomena, the controller can be adapted to a kind of temperature performance that is optimum for this particular refrigerating plant.

y Fastest possible cooling

y Cooling with less underswing

y Cooling where underswing is unwanted

Valve

The valve is an evaporating pressure valve and is available in several capacity sizes. The valve is mounted on a step engine which receives impulses from the controller. The controller is adapted to this valve. There is therefore only very few settings for the valve.

In case of power failure that valve's opening degree will be maintained. If the application requires the valve open in this situation a battery can be connected to the controller.

Manual Electronic media temperature controller, type EKC 368

Data

Supply voltage

Power consumption

Input signal *) Ri = 100 KΩ

Sensor input 2 pcs. Pt1000 ohm

Relay output 3 pcs. SPST

Alarm relay 1 pcs. SPST

Step motor output Pulsating 100 mA

Data communication Possible to connect a data communication module

Ambient temperature

Enclosure IP 20

Weight 300 g

Mounting DIN rail

Display LED, 3-digits

Terminals max. 2.5 mm2 multicore

Approvals

If battery backup is used: Requirements to battery: 18 V DC min. 100 mAh

24 V AC +/-15% 50/60 Hz, 10 VA (the supply voltage is galvanically separated from the input and output signals)

Controller KVS-step motor

Voltage signal* 0 – 10 V or 2 – 10 V

Digital input from external contact function

Short-circuit (pulse signal) of 18 – 20 will start a defrost

During operation During transport

EU Low Voltage Directive and EMC demands re CE-marking complied with LVD-tested acc. to EN 60730-1 and EN 60730-2-9 EMC-tested acc. to EN50081-1 and EN 50082-2

5 VA

1.3 VA

AC-1: 4 A (ohmic) AC-15: 3 A (inductive)

-10 – 55°C

-40 – 70°C

Ordering

Typ e Function Code No.

EKC 368 Evaporating pressure controller 084B7079

EKA 172 Realtime clock 084B7069

EKA 174 Data communication module (accessories),

(RS 485 module) with galvanic separation

AKA 211 Filter : 4 x 10 mH 084B2238

Temperature sensor Pt1000 ohm: Kindly refer to catalogue RK0YG... Valves: Kindly refer to catalogue RK0YG...

084B7124

Connections

Necessary connections

Terminals: 25 – 26 Supply voltage 24 V AC 18 – 19 Pt1000 sensor at evaporator outlet 21 – 24 Supply to step motor 1 – 2 Switch function for start/stop of regulation. If a switch is

not connected, terminals 1 and 2 must be short circuited

5 – 6 Battery (the voltage will open the KVS valve if the

controller loses its supply voltage)

Application dependent connections

Terminal: 12 – 13 Alarm relay There is connection between 12 and 13 in alarm situations and when the controller is dead 8 – 9 Relay switch for start/stop of defrost 8 – 10 Relay switch for start/stop of fan 8 – 11 Relay switch for start/stop of cooling 16 – 17 Voltage signal from other regulation (Ext.Ref.) If the voltage signal is received from a PLC or the like, a data communication module, if any, must be with galvanic separation. 18-20 Pt1000 sensor for defrost function. Short-circuit of the terminals for two seconds (pulse signal) will start a defrost 3-4 Data communication Mount only, if a data communication module has been mounted It is important that the installation of the data communi cation cable be done correctly. Cf. separate literature No. RC8AC...

Data communication

21 22 23 24

white black green red

L > 5 m, see page 12

4 DKRCC.PS.RP0.B1.02 / 520H9697 © Danfoss A/S (DCS-IMCGPD/sw), 2015-02

Manual Electronic media temperature controller, type EKC 368

Survey of functions

Function Parameters Parameter by operation via data communication

Normal display

Normally the temperature value is shown from room temperature Sair.

The temperature at the defrost sensor can be displayed by giving the lower button a brief push (1s).

Reference Reference

Regulation is based on the set value provided that there is no external contribution (o10).

(Push both buttons simultaneously to set the setpoint).

Temperature unit

Here you select whether the controller is to indicate the temperature values in °C or in °F.

If indication in °F is selected, other temperature settings will also change over to Fahrenheit, either as absolute values or as delta values.

External contribution to the reference

This setting determines how large a contribution is to be added to the set reference when the input signal is max. (10 V ).

Correction of signal from Sair

(Compensation possibility through long sensor cable).

Correction of signal from Sdef

(Compensation possibility through long sensor cable).

Start/stop of refrigeration

With this setting refrigeration can be started and stopped. Start/stop of refrigeration can also be accomplished with the external switch function. See also appendix 1.

Alarm

The controller can give alarm in dierent situations. When there is an alarm all the light-emitting diodes (LED) will ash on the controller front panel, and the alarm relay will cut in.

Alarm for upper deviation

The alarm for too high Sair temperature is set here. The value is set in Kelvin.

The alarm becomes active when the Sair temperature exceeds the actual reference plus A01. (The actual reference (SP + r06) can be seen in u02).

Alarm for lower deviation

The alarm for too low Sair temperature is set here. The value is set in Kelvin.

The alarm becomes active when the Sair temperature drops below the actual reference minus A02.

Alarm delay

If one of the two limit values is exceeded, a timer function will commence. The alarm will not become active until the set time delay has been passed. The time delay is set in minutes.

Battery alarm

Here it is dened whether the controller has to monitor the voltage from the battery backup. If there is low voltage or none at all an alarm will be given.

With data communication the importance of the individual alarms can be deﬁned. Setting is carried out in the “Alarm destinations” menu. See also page 14.

r05

r06 ExtRefOﬀset

r09 Adjust SAir

r11 Adjust SDef

r12 Main switch

A01 Upper oﬀset

A02 Lower oﬀset

A03 TempAlrmDel

A34 Batt. alarm

u01 Air temp

u09 Sdef temp

- Temp Setpoint

Temp unit °C = 0, °F = 1 (In AKM only bar is displayed, whatever the setting)

Manual Electronic media temperature controller, type EKC 368

Survey of functions

Function Parameters Parameter by operation via data communication

Defrost A defrost can be dened in three ways:

- via the data communication from a defrost table

- via short-circuiting of the Sdef sensor (pulse signal of 2 sec. duration)

- mounting of real time clock module Defrost is stopped when the temperature at the defrost sensor reaches the set value or when the set time expires. Temperature alarms are not active during defrost.

Defrost method

Here you have to set whether defrost is to be carried out with electricity or hotgas. During defrost the defrost relay will be operated and the cold relay cut out. If ELECTRICITY is used, the valve will be open during defrost. When GAS is used, the valve will be closed during defrost.

Defrost stop temperature

The temperature value is set. If a defrost sensor has not been mounted, defrost will be stopped on the basis of time. See later.

Max. defrost duration

If you have chosen to stop defrost based on temperature, this setting will constitute a safety period where defrost will be stopped, if it has not occurred based on temperature. If you have not mounted a defrost sensor, this setting will be the defrost time.

Drip-o time

Here you set the time that is to elapse from the end of a defrost and until refrigeration is to be resumed. (The time when water is dripping o the evaporator).

Delayed fan start after defrost

Here you set the time to elapse from refrigeration may be started after a defrost and until the fan may be started again. (The time where the water is “bound” to the evaporator).

Fan start temperature

The fan may also be started a little earlier than mentioned under “Delayed fan start after defrost” if the defrost sensor registers a permissible value. Here you can set the value for when the fan may start.

Fan cut in during defrost

Here you set whether the fan is to operate during defrost.

Delayed temperature alarm after defrost

During and immediately after a defrost the temperature is “too high”. The “high temperature alarm” can be suppressed right after a defrost. Here you must set for how long the alarm is to be suppressed. The time counts from the start of refrigeration.

If you wish to start an extra defrost, push the lower button for seven seconds. If you keep it depressed for seven seconds when a defrost is going on, the defrost will be stopped. The drip-o time and the fan delay will be completed.

If you wish to see the temperature at the defrost sensor, push the lower button briey (1s).

d01

d02 Def. Stop Temp

d04 Max Def.time

d06 DripOﬀtime

d07 FanStartDel

d08 FanStartTemp

d09 FanDuringDef

d11 Pulldown del

Defrost mode oﬀ = 0 El = 1 Gas = 2

Def. start Here you can start a manual defrost

u09 Sdef temperature

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Manual Electronic media temperature controller, type EKC 368

Survey of functions

Function Parameters Parameter by operation via data communication

Control parameters Actuator type

Here you dene the actuator mounted in the system: 1: KVS 15 - 22 2: KVS 38 - 35 3: KVS 42 - 54 4: User-dened (engine data can be changed via the AKM programme Danfoss only) Change of setting only when r12 = o.

P: Amplication factor Kp

If the Kp value is reduced the regulation becomes slower.

I: Integration time Tn

IThe I-setting can be cancelled by setting the value to max. (600s). If it is set to 600s, parameter n07 must be set to “0”. (If the Tn value is increased the regulation becomes slower).

D: Dierentiation time Td

The D-setting can be cancelled by setting the value to min. (0).

Transient phenomenon

If the refrigeration requires a very fast transient phenomenon or must not have an underswing or temperature shift, this function can be used. 0: Fastest possible cooling 1: Cooling with less underswing 2: Cooling where underswing is unwanted

Start-up after hotgas defrost

The KVS valve must be open before the solenoid valve for refrigeration may be opened. Here you set how much time the valve needs for opening. The period of time starts when the drip-o time has ended.

Miscellaneous Input signal

If you wish to connect a signal that is to displace the controller’s control reference, the signal must be dened in this menu. 0: No signal 1: 0 - 10 V 2: 2 - 10 V (0 or 2 V will not give a displacement. 10 V will displace the reference by the value set in menu r06).

Frequency

Set the net frequency.

Address

If the controller is built into a network with data communication, it must have an address, and the master gateway of the data communication must then know this address. These settings can only be made when a data communication module has been mounted in the controller and the installation of the data communication cable has been completed. This installation is mentioned in a separate document “RC.8A.C”.

The address is set between 1 and 60. o03 The address is sent to the gateway when the menu is set in pos.

ON (The setting will automatically change back to O after a few seconds).

n03 Valve type

n04 Kp factor

n05

n06 Td sec.

n07 Ctrl. mode

n08 Open time

o10 AI type

o12

o04

Tn sec.

50/60 Hz (50 = 0, 60 = 1)

Following installation of a data communication module, the controller can be operated on a par with the other controllers in ADAP-KOOL® refrigeration controls

Manual Electronic media temperature controller, type EKC 368

Survey of functions

Function Parameters Parameter by operation via data communication

Service

A number of controller values can be printed for use in a service situation.

Read the temperature at the Sair sensor

(calibrated value).

Read the control reference

(Set reference + any contribution from external signal).

Read value of external voltage signal u07 AI Volt Read temperature at the Sdef sensor

(calibrated value).

Read status of input DI

(start/stop input).

Read the duration of the ongoing defrost

or the duration of the last completed defrost.

Read opening degree of the valve in % u23 KVS OD %

Operating status

The controller goes through some regulating situations where it is just waiting for the next point of the regulation. To make these “why is nothing happening” situations visible, you can see an operating status on the display. Push briey (1s) the upper button. If there is a status code, it will be shown on the display. (Status codes have lower priority than alarm codes. In other words, you cannot see a status code, if there is an active alarm). The individual status codes have the following meanings:

S4: Defrost sequence. The evaporator drips o and waits for the time to run out.

S10: Refrigeration stopped by the internal or external start/ stop. 10 S12: Refrigeration stopped due to low Sair. 12 S13: Defrost sequence. The KVQ valve is closing. 13 S14: Defrost sequence. Defrost in progress. 14 S15: Defrost sequence. The fan waits for the time to run out. 15

u01 Air temp.

u02 Air ref.

u09 Sdef temp

u10 DI status

u11 Defrost time

Alarm relay

-- Cooling rel.

-- Fan relay

-- Def. relay

Read status of alarm relay ON is operating status with alarm

Read status of relay for solenoid valve

Read status of relay for fan

Read status of relay for defrost

Ctrl state (0 = regulation)

8 DKRCC.PS.RP0.B1.02 / 520H9697 © Danfoss A/S (DCS-IMCGPD/sw), 2015-02

Manual Electronic media temperature controller, type EKC 368

Operation Menu survey

Display

The values will be shown with three digits, and with a setting you can determine whether the temperature are to be shown in °C or in °F.

Light-emitting diodes (LED) on front panel

There are LED’s on the front panel which will light up when the belonging relay is activated. The three lowermost LED’s will ash, if there is an error in the regulation. In this situation you can upload the error code on the display and cancel the alarm by giving the uppermost button a brief push.

The controller can give the following messages

E6 Change battery in timer. Set the timer

Error message

E7 Cut-out Sair

E8 Short circuited Sair

E12 Analog input signal is outside the range

A2 Low-temperature alarm

Alarm message

A43 Check supply voltage for the step engine

A44 Battery alarm (no voltage or too low voltage)

Errors in the controller

High-temperature alarm

The buttons

When you want to change a setting, the two buttons will give you a higher or lower value depending on the button you are pushing. But before you change the value, you must have access to the menu. You obtain this by pushing the upper button for a couple of seconds - you will then enter the column with parameter codes. Find the parameter code you want to change and push the two buttons simultaneously. When you have changed the value, save the new value by once more pushing the two buttons simultaneously.

Gives access to the menu (or cutout an alarm)

Gives access to changes

Saves a change

Examples of operations

Set reference temperature

1. Push the two buttons simultaneously

2. Push one of the buttons and select the new value

3. Push both buttons again to conclude the setting

Set one of the other menus

1. Push the upper button until a parameter is shown

2. Push one of the buttons and nd the parameter you want to change

3. Push both buttons simultaneously until the parameter value is shown

4. Push one of the buttons and select the new value

5. Push both buttons again to conclude the setting

SW =1.6x

180 min

min

199 min

min

Fac.

setting

Function Param. Min. Max.

Normal display Shows the temperature at the room sensor - °C Give the lower button a brief push to see

the temperature at the defrost sensor Reference Set the required room temperature - -70°C 160°C 10 Temperature unit r05 °C °F °C External contribution to the reference r06 -50 K 50 K 0 Correction of the signal from Sair r09 -10.0 K 10.0 K 0 Correction of the signal from Sdef r11 -10.0 K 10.0 K 0 Start/stop of refrigeration r12 OFF On On Alarm Upper deviation (above the temperature

setting) Lower deviation (below the temperature

setting)

Alarm’s time delay A03 0

Monitoring of battery A34 Oﬀ On Oﬀ Defrost Defrost method (ELECTRICITY/GAS) d01 Oﬀ GAS Oﬀ Defrost stop temperature d02 0 25°C 6

Max. defrost duration d04 0

Drip-o time d06 0

Delay for fan start or defrost d07 0

Fan start temperature d08 -15°C 0°C -5 Fan cut in during defrost (yes/no) d09 no yes no

Delay for temperature alarm after defrost d11 0

Regulating parameters Actuator type: 1 = KVS15-22, 2 = KVS28-35,

3 = KVS42-54 4 = User dened via AKM / For Danfoss only Setting of menu only when r12 = o.

P: Amplication factor Kp n04 1 50 4 I: Integration time Tn (600 = o ) n05 60 s 600 s 120 D: Dierentiation time Td (0 = o ) n06 0 s 60 s 0 Transient phenomenon

0: Fast cooling 1: Cooling with less underswing 2: Cooling where underswing is unwanted

Start-up time after hotgas defrost n08 0 min

Miscellaneous Controller’s address o03*) 1 60 0 ON/OFF switch (service-pin message) o04*) - - Oﬀ Dene input signal of analog input

0: no signal 1: 0 – 10 V 2: 2 – 10 V

Set supply voltage frequency o12 50 Hz 60 Hz 50 Service Read temperature at the Sair sensor u01 °C Read regulation reference u02 °C Read value of external voltage signal u07 V Read temperature at the Sdef sensor u09 °C Read status of input DI u10 on/oﬀ Read duration of defrost u11 m Opening degree of the valve u23 %

*) This setting will only be possible if a data communication module has been installed in the controller.

- °C

A01 0 50 K 5

A02 0 50 K 5

n03 1 4 1

n07 0 2 1

o10 0 2 0

Manual Electronic media temperature controller, type EKC 368

Start of controller Fine adjustments

When the electric wires have been connected to the controller, the following points have to be attended to before the regulation starts:

1. Switch o the external ON/OFF switch that starts and stops the regulation

2. Follow the menu survey on page 8, and set the various parameters to the required values

3. Switch on the external ON/OFF switch, and regulation will start

4. If the system has been tted with a thermostatic expansion valve, it must be set to minimum stable superheating

5. Follow the actual room temperature on the display. (Use a data collection system, if you like, so that you can follow the temperature performance)

If the temperature uctuates

When the refrigerating system has been made to work steadily, the controller’s factory-set control parameters should in most cases provide a stable and relatively fast regulating system. If the system on the other hand oscillates, you must register the periods of oscillation and compare them with the set integration time Tn, and then make a couple of adjustments in the indicated parameters.

If the time of oscillation is longer than the integration time: (Tp > Tn , (Tn is, say, 4 minutes))

1. Increase Tn to 1.2 times T

2. Wait until the system is in balance again

3. If there is still oscillation, reduce Kp by, say, 20%

4. Wait until the system is in balance

5. If it continues to oscillate, repeat 3 and 4

When the system has been operating for a while, it may be required for some systems to optimise some of the adjustments. Below we have a look at settings having an inuence on the speed and accuracy of the regulation.

Method for xing Kp, Tn and T

Described below is a method (Ziegler-Nichols) for xing Kp, Tn and Td.

1. The system is made to regulate the temperature at the required reference with a typical load. It is important that the valve regulates, and that it is not fully open The controller is set, so that it will regulate as a P-controller. (Td is set to 0, Tn in pos. OFF (600), and Q-Ctrl.mode (n07) is set at 0) The stability of the system is examined by stopping the system for, say, one minute (using the start/stop setting or the switch). Now check how the building-up of the temperature proceeds. If the building-up peters out, raise Kp a little and repeat the start/stop operation. Continue with this until you obtain a building-up which does not peter out

2. Kp is in this case the critical amplication (K

pcritical

) and the building-up time for the continued oscillation is the critical building-up time (T

critical

)

3. Based on these values, the regulating parameters can now be calculated and subsequently set:

y If PID regulation is required:

Kp < 0,6x K Tn > 0,5x T Td < 0,12x T

pcritical

critical

y If PI regulation is required:

Kp < 0,45x K Tn > 0,85x T

pcritical

critical

6. Reset value for “Q-Ctrl.mode” (n07)

If the time of oscillation is shorter than the integration time: (Tp < Tn , (Tn is, say, 4 minutes))

1. Reduce Kp by, say, 20% of the scale reading

2. Wait until the system is in balance

3. If it continues to oscillate, repeat 1 and 2

Manual Electronic media temperature controller, type EKC 368

Data communication

This page contains a description of a few of the possibilities you will have when the controller is provided with data communication.

Each controller is provided with a plug-in module.

The controllers are then connected to a two-core cable.

Up to 60 controllers may be connected to one cable.

This cable is also connected to a gateway type AKA 243.

This gateway will now control the communication to and from the controllers.

It will collect temperature values and it will receive alarms. When there is an alarm the alarm relay will be activated for two minutes.

If you want to know more about operation of controllers via PC, you may order additional literature.

The gateway can now be connected to a modem.

When an alarm occurs from one of the controllers, the gateway will, via the modem, make a phone call to the service company.

At the service company a modem, gateway and PC with system software type AKM have been installed.

All the controllers’ functions can now be operated from the various menu displays.

The programme will for example upload all the collected temperature values once a day.

Example of menu display

y Measurements are shown at

one side and settings at the other

y You will also be able to see

the parameter names of the functions on page 4 – 7

y With a simple change-over

the values can also be shown in a trend diagram

y If you wish to check earlier

temperature measurements, you can see them in the log collection

Alarms

If the controller is extended with data communication, it will be possible to dene the importance of the transmitted alarms. The importance is dened with the setting: 1, 2, 3 or 0. When the alarm then arises at some time, it will result in one of the following activities:

1 = Alarm

The alarm message is sent o with alarm status 1. This means that the gateway that is the master in the system will have its alarm relay output activated for two minutes. Later, when the alarm ceases, the alarm text will be retransmitted, but now with status value 0.

2 = Message

The alarm text is transmitted with status value 2. Later, when the “message” lapses, the alarm text is retransmitted, but now with status value 0.

3 = Alarm

As “1”, but the master gateway’s relay output is not activated.

0 = Suppressed information

The alarm text is stopped at the controller. It is transmitted nowhere.

Manual Electronic media temperature controller, type EKC 368

Trouble shooting

In addition to the error messages transmitted by the controller, the table below may help identifying errors and defects.

Symptom Defect Conrmation of defect

Evaporator blocked with ice. Defrost function in order

Evaporator blocked with ice. Defrost function not in order

Defrost period too long

Appendix 1

Interaction between internal and external start/stop functions and active functions.

Internal Start/stop O O On On External Start/stop O On O On Refrigeration O On Fan relay O On Expansion valve relay O On Defrost relay On/o On/o Temperature monitoring No Ye s Sensor monitoring Yes Yes

If a start/stop function is put in pos. OFF during a defrost, the defrost will be carried out as planned

Defrost set incorrectly, or placing of Sdef is not correct

Defrost sensor Sdef cut out Check sensor

Defrost sensor Sdef is short-circuited

Heating element is not cut in

Defrost set incorrectly Check setting of the stop temperature Defrost continues beyond the set stop

temperature

Check setting / check sensor location

Check if the function that starts defrost is stuck

Check the heating element and the defrost relay

Check location of Sdef

KVS connection

If the distance between EKC 368 and the KVS valve exceeds 5 m a lter must be mounted to obtain the correct valve function.

L < 5 m

5 m < L < 50 m

Danfoss EKC 368 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual