EVCO EPU2LXP1CH Installer manual - Manual (Page 68)

EVCO S.p.A. c-pro 3 micro CHIL | Application manual ver. 1.0 | Codice 144CP3CHE104
page 68 of 120
8.11 Circulating Source Pump Management
On WATER-TO-WATER machines, 1 or 2 source water-circulating pumps can be controlled, which are defined by the parameter PG10.
The Pump operation PP21 parameter defines how the pump will operate.
Regulations, status, flow meter controls and safeties for these devices are the same as of the circulating pumps describedabove.
8.12 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 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.
II
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.