AKC 25H1
Function description
RC.1J.Z4.02
©
Danfoss
09/1999
13
Monitoring of minimum suction pressure
The function immediately cuts out all compressor steps if the suction pressure becomes lower
than the permitted value. The cut out limit can be defined in the range between -100 and
+30
°
C.
The suction pressure is measured with the pressure transmitter on the PO input.
Cut outs activate:
- the alarm function and
- the function “AKC ON” is interrupted.
The alarm ceases when the following conditions are complied with:
- the pressure (temperature) is above the cut out limit
- the delay time has ecpired (see later)
Renewed cut in of compressor steps is allowed when the following conditions are complied
with:
- the alarm has stopped (the time delay has expired)
- the time delay prior to renewed cutin has expired
Safety functions
Limits with 1.Priority
P0 Min
°
C ___
Time delay
There is a common time delay period for the three earlier mentioned functions: Monitoring of
max. discharge temperature, max. discharge pressure, and min. suction pressure.
After a cut out, regulation cannot commence again until the time delay has expired.
The time delay starts when the temperature has again dropped to 10 K and 3 K, respectively,
below the limit value. Or when the pressure has risen above the P0min value.
The time delay can be defined in the range between 0 and 30 minutes.
Safety functions
Limits with 1.Priority
Restart m ___
Monitoring of suction gas superheat
The function monitors the superheat and gives an alarm, if the superheat becomes higher or
lower than the defined values.
Superheat is measured with the pressure transmitter on the PO input and the temperature
sensor on the Ss input.
Maximum superheat
The alarm limit can be defined in the range between 20 and +80 K.
Minimum superheat
The alarm limit can be defined in the range between 0 and +20 K.
Time delay
The alarm will not be sounded until the time delay has expired. The time delay can be defined
in the range between 0 and 60 minutes.
Safety functions
Limits with 1.Priority
SH Max K ___
SH Min K ___
SH Delay m ___
