EVCO c-pro nano CHIL - Manual (Page 116)

C-PRO NANO CHIL AND C-PRO MICRO CHIL – APPLICATION MANUAL
Pag. 116
6.12 Defrosting Management
This procedure is only activated in winter operating mode (heat pump), and when at least one
compressor is switched ON. Defrosting is performed by intervening on the refrigerating-circuit
inverter valve.
If evaporation pressure/temperature remains (even if not continuously), for a time interval equal to
the value of parameter Defrosting enable delay Pd03, below the threshold of the Defrosting start set
point Pd01 and at least one compressor is in operation, the inverter valve is commutated and the
defrosting cycle is started. During this phase, compressors are forced to maximum power, and the
low-pressure alarm is bypassed.
Defrosting is interrupted for one of the following causes:
- When pressure reaches the End of defrosting set point Pd02;
- When the Defrosting duration max. time Pd05 has elapsed;
- When machine or circuit alarms have been triggered;
- When the unit has been switched OFF.
At the end of the defrosting cycle, the unit remains stationary for the whole duration of Dripping
time Pd06.
In order to avoid the immediate start of a defrosting cycle after all compressors have been stopped,
a Minimum circuit restart delay Pd07 is used, which guarantees at least a period of heat-pump
operation, before entering the defrosting cycle.
Note: In the case of twin-circuit units, defrosting cannot be simultaneous; thus, if one circuit is
defrosting, the other circuit cannot start a defrosting cycle until the defrosting circuit has completely
finished its cycle.
Pressure
Pd02
Pd01
Pd03
Pd04
Inverter valve
Pd06
Defrost Dripp.