Optyma Plus
TM
User
Guide RS8GD602 © Danfoss 2015-10
7
Compressor
Compressor control
The start/stop of the controller can be defined in several ways.
Internal only: Here, only the internal main switch in r12 is used.
External: Here, input DI1 is used as a thermostat switch. With this setting, input DI2
can be defined as an 'external safety' mechanism that can stop the compressor.
Running times
To prevent irregular operation, values can be set for the time the compressor is to run
once it has been started. And for how long it at least has to be stopped.
Min. ON-time (in seconds)
c01
Min. On time
Min. OFF-time (in seconds)
c02
Min. Off time
Minimum time between cut-in of relay
(in minutes)
c07
Restart time
Pump down Limit
Pressure value at which the compressor stops
c33
PumpDownLim
Compressor min. speed
Here the minimum allowable speed for the compressor is set.
c46
CmpMinSpeed
Compressor start speed
The compressor will not start before the required speed can be achieved
c47
CmpStrSpeed
Compressor max. speed
Upper limit for compressor speed
c48
CmpMaxSpeed
Compressor max. speed during night operation
Upper limit for compressor speed during night operation. During night operation, the
c48 value is reduced to the percentage value set here
c69
CmpMax % Ngt
Definition of compressor control
0: No external switch for start/stop
1: Input DI1 used to start and stop the compressor
2: The compressor will be speed-controlled with a 0-10 V signal on AO2
c71
Comp mode
Delay time for high discharge gas temperature
(in minutes)
When sensor Td records a temperature higher than the limit value entered in r84, the
timer will start. When the delay time expires, the compressor will be stopped if the
temperature is still too high. An alarm will also be issued.
c72
Disch. Del
Max. pressure (Max. condensing pressure)
The maximum permitted condensing pressure is set here. If the pressure increases,
the compressor will be stopped.
c73
PcMax
Difference for max. pressure (Condensing pressure)
Difference for re-start of compressor if it is cut out due to PcMax.
(All timers must expire before re-start is permitted)
c74
Pc Diff
Minimum suction pressure
Enter the lowest permitted suction pressure here. The compressor is stopped if the
pressure drops below the minimum value.
c75
PsLP
Suction pressure difference
Difference for re-start of compressor if it is cut out due to PsLP.
(All timers must expire before re-start is permitted)
c76
PsDiff
Amplification factor Kp for compressor regulation
If the Kp value is lowered, the regulation will be slower
c82
Cmp Kp
Integration time Tn for compressor regulation
If the Tn value is increased, regulation will run more smoothly
c83
Comp Tn sec
Liquid Injection Offset
The liquid injection relay is activated when the temperature is over “r84” minus “c88”
(but only if the compressor is running).
c88
LI Offset
Liquid Injection hysterese
The liquid injection relay is then deactivated when the temperature has dropped to
“r84” minus “c88” minus “c89”.
c89
LI Hyst
Compressor stop delay after Liquid injection
Compressor ON-time after relay "Aux relay" is went OFF
c90
LI Delay
Desired compressor speed in connection with pressure transmitter faults.
Speed during emergency operation.
c93
CmpEmrgSpeed
Min On time during Low Ambient Temperature and Low Pressure
c94
c94 LpMinOnTime
Measured Tc for which the Comp min speed is raised to StartSpeed
c95
c95 TcSpeedLim
The LED on the controller’s front will show whether refrigeration is in progress.
Fan
Fan control
Amplification factor Kp
If the KP value is lowered, the fan speed will change.
n04
Kp factor
