Danfoss AK-PC 781A User Manual page 118

Extra refrigeration capacity ("extra compressor")
This function improves the system's refrigeration capacity by
increasing the pressure in the gas cooler. The function will start
when the compressor capacity has been at 100% for 5 minutes.
The cooling performance increases to Q0+dh0.
The function also increases the load on the compressor motor as
pressure increases. Power consumption increases to Qm+dQm.
Increasing pressure reference with heat recovery
The function will increase the gas pressure reference to the Pgc HR
Min. value when it receives a signal.
The function is activated by signal from the heat recovery
Increasing pressure reference with heat recovery, variable
reference
The function will increase the gas pressure reference to the value
where it receives a signal.
The function is activated by a signal from the heat recovery.
• From ON at 0%: Here the reference is changed to "Pgc HR Min."
• To ON at 100%: Here the reference will increase further using the
setting "Pgc HR offset".
• Between 0 and 100% the reference is variable.
118 Capacity controller RS8HE202 © Danfoss 2017-07
Start-up at a very low temperature
It will be necessary to route the gas outside of the gas cooler if the
gas temperature is too low.
Temperature limits are set under the function "Bypass low limit".
When the function is active, the gas temperature is measured by
the Shp sensor. When the sensor records a value that is 5K higher
than the set value, it will switch back again so that the gas is
routed through the gas cooler. The switch will only take place after
the pre-set delay time "Bypass permitted after" has passed.
Warning
Remember that the controller controls the gas pressure. If the
regulation is stopped by the internal or external main switch, this
control will stop as well.
Risk of loss of charge.
If the compressors are stopped via the function "External com-
pressor stop", control of the gas pressure will continue.
AK-PC 781A