Danfoss AK-CC 210 User guide

User Guide
Controller for temperature control
AK-CC 210
ADAP-KOOL® Refrigeration control systems
Contents
Introduction ....................................................................................................... 2
Operation ............................................................................................................ 3
Applications ....................................................................................................... 6
Survey of functions .......................................................................................... 8

Introduction

Application
• With many predefined applications one unit will offer you many options. Flexibility has been planned both for new installations and for service in the refrigeration trade
Principle
The controller contains a temperature control where the signal can be received from one or two temperature sensors. The thermostat sensors are either placed in the cold air flow after the evaporator, in the warm air flow just before the evaporator, or both. A setting will determine how great an influence the two signals are to have on the control. A measurement of the defrost temperature can be obtained directly through the use of an S5 sensor or indirectly through the use of the S4 measurement. Four relays will cut the required functions in and out – the application determines which. The options are the following:
• Refrigeration (compressor or relay)
• Fan
• Defrost
• Rail heat
• Alarm
• Light
• Fans for hotgas defrost
• Refrigeration 2 (compressor 2 or relay 2)
Operation .......................................................................................................... 18
Menu survey .....................................................................................................20
Ordering ............................................................................................................22
Connections ..................................................................................................... 23
Data ..................................................................................................................... 24
The different applications are described on page 6.
Advantages
• Many applications in the same unit
• The controller has integrated refrigeration-technical functions, so that it can replace a whole collection of thermostats and timers
• Buttons and seal imbedded in the front
• Can control two compressors
• Easy to remount data communication
• Quick setup
• Two temperature references
• Digital inputs for various functions
• Clock function with super cap backup
• HACCP (Hazard Analysis and Critical Control Points)
- Temperature monitoring and registration of period with too high temperature (see also page 19)
- Factory calibration that will guarantee a better measuring accuracy than stated in the standard EN ISO 23953-2 without subsequent calibration (Pt 1000 ohm sensor)
2 User Guide RS8EP602 © Danfoss 2018-11 AK-CC 210

Operation

Sensors
Up to two thermostat sensors can be connected to the controller. The relevant application determines how.
A sensor in the air before the evaporator: This connection is primarily used when control is based on area.
A sensor in the air after the evaporator: This connection is primarily used when refrigeration is controlled and there is a risk of a too low temperature near the products.
A sensor before and after the evaporator: This connection offers you the possibility of adapting the thermostat, the alarm thermostat and the display to the relevant application. The signal to the thermostat, the alarm thermostat and the display is set as a weighted value between the two temperatures, and 50% will for example give the same value from both sensors. The signal to the thermostat, the alarm thermostat and the display can be set independently of one another.
Defrost sensor The best signal concerning the evaporator’s temperature is obtained from a defrost sensor mounted directly on the evaporator. Here the signal may be used by the defrost function, so that the shortest and most energy-saving defrost can take place.
If a defrost sensor is not required, defrost can be stopped based on time, or S4 can be selected.
Control of two compressors
This control is used for controlling two compressors of the same size. The principle for control is that one of the compressors connects at ½ the differential of the thermostat, and the other at the full differential. When the thermostat cuts in the compressor with the fewest operating hours is started. The other compressor will only start after a set time delay, so that the load will be divided between them. The time delay has a higher priority than the temperature. When the air temperature has dropped by half the differential the one compressor will stop, the other will continue working and not stop until the required temperature is achieved. The compressors used must be of a type that is capable of starting up against a high pressure.
Change of temperature reference
In an impulse appliance, for example, used for various product groups. Here the temperature reference is changed easily with a contact signal on a digital input. The signal raises the normal thermostat value by a predefined amount. At the same time the alarm limits with the same value are displaced accordingly.
AK-CC 210 User Guide RS8EP602 © Danfoss 2018-11 3
Digital inputs
There are two digital inputs both of which can be used for the following functions:
- Case cleaning
- Door contact function with alarm
- Starting a defrost
- Coordinated defrost
- Change-over between two temperature reference
- Retransmission of a contact’s position via data communication
Case cleaning function
This function makes it easy to steer the refrigeration appliance through a cleaning phase. Via three pushes on a switch you change from one phase to the next phase. The first push stops the refrigeration – the fans keep working ”Later”: The next push stops the fans ”Still later”: The next push restarts refrigeration The different situations can be followed on the display.
On the network a cleaning alarm is transmitted to the system unit. This alarm can be ”logged” so that proof of the sequence of events is provided.
- + + °C
1 ÷ + Fan
2 ÷ ÷ Off
3 + + °C
Door contact function
In cold rooms and frost rooms the door switch can switch the light on and off, start and stop the refrigeration and give alarm if the door has remained open for too long.
Defrost
Depending on the application you may choose between the fol­lowing defrost methods: Natural: Here the fans are kept operating during the defrost Electric: The heating element is activated Brine: The valve is kept open so that the brine can flow through the evaporator Hotgas: Here the solenoid valves are controlled so that the hotgas can flow through the evaporator
Start of defrost
A defrost can be started in different ways Interval: Defrost is started at fixed time intervals, say, every eighth hour Refrigeration time: Defrost is started at fixed refrigeration time inter- vals, in other words, a low need for refrigeration will ”postpone” the coming defrost Schedule: Here defrost can be started at fixed times of the day and night. However, max. 6 times Contact: Defrost is started with a contact signal on a digital input Network: The signal for defrost is received from a system unit via the data communication S5 temp In 1:1 systems the efficiency of the evaporator can
be followed. Icing-up will start a defrost.
Manual: An extra defrost can be activated from the control-
ler’s lower-most button. (Though not for
application 4).
Hot gas application
All the mentioned methods can be used at random – if just one them is activated a defrost will be started.
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Coordinated defrost
There are two ways in which coordinated defrost can be arranged. Either with wire connections between the controllers or via data communication
Wire connections
One of the controllers is defined to be the controlling unit and a battery module may be fitted in it so that the clock is ensured backup. When a defrost is started all the other controllers will follow suit and likewise start a defrost. After the defrost the indi­vidual controllers will move into waiting position. When all are in waiting position there will be a change-over to refrigeration. (If just one in the group demands defrost, the others will follow suit).
Defrost via data communication
All controllers are fitted with a data communication module, and via the override function from a gateway the defrost can be coordinated.
Defrost on demand
1 Based on refrigeration time
When the aggregate refrigeration time has passed a fixed time, a defrost will be started.
Max. 15
2 Based on temperature
The controller will constantly follow the temperature at S5. Between two defrosts the S5 temperature will become lower the more the evaporator ices up (the compressor operates for a longer time and pulls the S5 temperature further down). When the temperature passes a set allowed variation the defrost will be started. This function can only work in 1:1 systems
Extra module
• The controller can afterwards be fitted with an insertion module if the application requires it. The controller has been prepared with plug, so the module simply has to be pushed in
- Battery module
The module guarantees voltage to the controller if the supply voltage should drop out for more than four hours. The clock function can thus be protected during a power failure.
- Data communication
If you require operation from a PC, a data communication mod­ule has to be placed in the controller.
• External display
If it is necessary to indicate the temperature on the front of re­frigeration appliance, a display type EKA 163A can be mounted. The extra display will show the same information as the control­ler's display, but does not incorporate buttons for operation. If operation from the external display is needed a display type EKA 164A must be mounted.
AK-CC 210 User Guide RS8EP602 © Danfoss 2018-11 5

Applications

Here is a survey of the controller’s field of application.
A setting will define the relay outputs so that the controller’s interface will be targeted to the chosen application.
On page 20 you can see the relevant settings for the respective wiring diagrams.
S3 and S4 are temperature sensors. The application will deter­mine whether either one or the other or both sensors are to be used. S3 is placed in the air flow before the evaporator. S4 after the evaporator. A percentage setting will determine according to what the control is to be based. S5 is a defrost sensor and is placed on the evaporator. DI1 and DI2 are contact functions that can be used for one of the following functions: door function, alarm function, defrost start, external main switch, night operation, change of thermostat ref­erence, appliance cleaning, forced refrigeration or coordinated defrost. See the functions in settings o02 and o37.
Refrigeration control with one compressor
The functions are adapted to small refrigeration systems which either may be refrigeration appliances or cold rooms. The three relays can control the refrigeration, the defrost and the fans, and the fourth relay can be used for either alarm function, light control or rail heat control
• The alarm function can be linked up with a contact function from a door switch. If the door remains open longer than al­lowed there will be an alarm.
• The light control can also be linked up with a contact function from a door switch. An open door will switch on the light and it will remain lit for two minutes after the door has been closed again.
• The rail heat function can be used in refrigeration or freezing appliances or on the door’s heating element for frost rooms.
The fans can be stopped during defrost and they may also follow a door switch’s open/close situation.
There are several other functions for the alarm function as well as the light control, rail heat control and fans. Please refer to the respective settings.
1
2
Danfoss
84B2428.12
Danfoss
84B2429.13
Hot gas defrost
This type of connection can be used on systems with hotgas defrost, but only in small systems in, say, supermarkets – the functional content has not been adapted to systems with large charges. Relay 1’s change-over function can be used by the bypass valve and/or the hotgas valve. Relay 2 is used for refrigeration.
3
4
Danfoss
84B2430.13
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Refrigeration control with two compressors
This group of applications can be used if the controller is to cut two compressors in and out. The functions can be compared with wiring diagrams 1 to 3, but instead of controlling fans the relay is here used for compressor
2.
The two compressors must be of the same size. When the controller demands refrigeration it will first cut in the compres­sor with the shortest operating time. After the time delay the second compressor will be cut in.
When the temperature has dropped to ”the middle of the dif­ferential”, the compressor with the longest operation time will be cut out. If the running compressor does not manage to reduce the tem­perature to the cutout point, the other compressor will be cut in again. This happens when the temperature reaches the top part of the differential. If the temperature is instead ”stuck” in the dif­ferential for two hours, there will be a change-over between the two compressors so that the operating time can be equalised. The two compressors must be of a type that can start up against a high pressure.
The compressors’s settings for ”Min On time” and ”Min Off time” will always have top priority during normal regulation. But if one of the override functions is activated, the ”Min On time” will be disregarded.
5
6
7
If the controller is to cut 2 compressor and 1 fan in and out, relay 4 must cut the fan in and out. This function is activated in application 10.
Simple refrigeration with defrost
This application can be used where there is only regulation of refrigeration and defrost.
Heating function
This application is the same as under 1, but a heating function has been added which protects the unit against too low tem­perature. The defrost function’s heating element is here used for heating.
10
8
9
This application is used where the temperature can go below the set cutout temperature for the refrigeration. To ensure that the temperature will not become too low the heating element is activated x degrees below the reference value. The S3 sensor must be mounted. It supplies the signal when there is heating.
AK-CC 210 User Guide RS8EP602 © Danfoss 2018-11 7

Survey of functions

Function Para-
meter
Normal display
Normally the temperature value from one of the two thermostat sensors S3 or S4 or a mixture of the two measurements is displayed. In o17 the ratio is determined.
Thermostat Thermostat control Set point
Regulation is based on the set value plus a displacement, if applicable. The value is set via a push on the centre button. The set value can be locked or limited to a range with the settings in r02 and r 03. The reference at any time can be seen in ”u28 Temp. ref”
Differential
When the temperature is higher than the reference + the set differential, the com­pressor relay will be cut in. It will cut out again when the temperature comes down to the set reference.
Ref. Dif.
Setpoint limitation
The controller’s setting range for the setpoint may be narrowed down, so that much too high or much too low values are not set accidentally - with resulting damages.
To avoid a too high setting of the setpoint, the max. allowable reference value must be lowered.
To avoid a too low setting of the setpoint, the min. allowable reference value must be increased.
Correction of the display’s temperature showing
If the temperature at the products and the temperature received by the controller are not identical, an offset adjustment of the shown display temperature can be carried out.
Temperature unit
Set here if the controller is to show temperature values in °C or in °F.
Correction of signal from S4
Compensation possibility through long sensor cable
Correction of signal from S3
Compensation possibility through long sensor cable
Start / stop of refrigeration
With this setting refrigeration can be started, stopped or a manual override of the outputs can be allowed. Start / stop of refrigeration can also be accomplished with the external switch func­tion connected to a DI input. Stopped refrigeration will give a ”Standby alarm”.
Night setback value
The thermostat’s reference will be the setpoint plus this value when the controller changes over to night operation. (Select a negative value if there is to be cold ac­cumulation.)
Selection of thermostat sensor
Here you define the sensor the thermostat is to use for its control function. S3, S4, or a combination of them. With the setting 0%, only S3 is used (Sin). With 100%, only S4. (For application 9 an S3 sensor must be used)
Heating function
The function uses the defrost function’s heating element for raising the temperature. The function enters into force a number of degrees (r36) below the actual reference and cuts out again with a differential of 2 degrees. Regulation is carried out with 100% signal from the S3 sensor. The fans will be operating when there is heating. The fans and the heating function will stop if door function has been selected and the door is opened. Where this function is used an external safety cutout should also be installed, so that superheating of the heating element cannot take place. Remember to set D01 to electrical defrosting.
Parameter by operation via data communication
Display air (u56)
Cutout °C
r01 Differential
r02 Max cutout °C
r03 Min cutout °C
r04 Disp. Adj. K
r05 Temp. unit
°C=0. / °F=1 (Only °C on AKM, whatever the set­ting)
r09 Adjust S4
r10 Adjust S3
r12 Main Switch
1: Start 0: Stop
-1: Manual control of outputs allowed
r13 Night offset
r15 Ther. S4 %
r36 HeatStartRel
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