AK-CC 550
Manual RS8EN502 © Danfoss 02-2010
15
Survey of functions
Function
Para-
meter
Parameter by operation via data
communication
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.
Display air (u56)
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 "u91 Cutout temp".
Cutout °C
Differential
When the temperature is higher than the ref the set differential, the com
-
pressor relay will be cut in. It will cut out again when the temperature comes down to
the set reference.
r01
Differential
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 may be
lowered.
r02
Max cutout °C
To avoid a too low setting of the setpoint, the min. allowable reference value may be
increased.
r03
Min cutout °C
Correction of the display’s temperature
If the temperature at the products and the temperature received by the controller are
not identical, an offset adjustment of the display temperature can be carried out.
r04
Disp. Adj. K
Temperature unit
Set here if the controller is to show temperature values in °C or in °F.
r05
Temp. unit
°C=0. / °F=1
(Only °C on AKM, whatever the set
-
ting)
Correction of signal from S4
Compensation possibility due to long sensor cable
r09
Adjust S4
Correction of signal from S3
Compensation possibility due to long sensor cable
r10
Adjust S3
Start / stop of refrigeration
With this setting refrigeration can be started, stopped or a manual override of the
outputs can be allowed. (For manual control the value is set at -1. Then the AKV outlet
and the relay outlets can be force-controlled by the respective reading parameters
(u23, u58, etc.). Here the read value can be overwritten.)
Start / stop of refrigeration can also be accomplished with the external switch func
-
tion connected to a DI input.
Stopped refrigeration will give a ”Standby alarm”.
r12
Main Switch
1: Start
0: Stop
-1: Manual control of outputs allowed
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 ac
-
cumulation.)
r13
Night offset
Thermostat function
Here it is defined how the thermostat is to operate. Either as an ordinary ON/OFF ther
-
mostat or as a modulating thermostat.
1: ON/OFF thermostat
2: Modulating
When operation is ”modulating” the AKV valve will limit the flow of refrigerant so that
the temperature variation will be less than for the ON/OFF thermostat.
The differential (r01) must not be set lower than 2K for "modulating".
In a decentralised plant you must select the ON/OFF thermostat setting.
r14
Therm. mode
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.
r15
Ther. S4 %
Melt function
Only for control of refrigeration (-5 to +10°C). The function ensures that the evapora
-
tor will not be blocked by frost. Here you set how often the function is to stop the
refrigeration and hence transform the frost to water (or ice if there is too much frost).
r16
MeltInterval
Melt period
Here you set how long an on-going melt function is to last.
r17
Melt period
Ref.
Dif.
