User manual

1592022700 User manual iCHILL 200CX Rel. 1.0 22/04/2009
It is possible to have the pump down procedure also without pressostat or pressure trasducers ; in this case, by configuring CO52 and
CO53, the compressor is switched off after CO52 time starting from pump down valve activation and switched on after CO53 time
starting from pump down valve deactivation.
CO 52
Maximum time for the activation of the pump-down during the switching off
CO52 = 0 Not enabled
0 250 Sec
CO 53
Maximum time for the activation of the pump-down during the switching on
CO53 = 0 Not enabled
0 250 Sec
24 UNLOADING
24.1 HIGH TEMPERATURE OF THE EVAPORATOR WATER INLET
The function is always enabled in chiller mode if there are at least 2 steps of capacity (circuit 1 with two compressor or 1 compressor
with partialization per circuit).
It is used to run the unit with high temperature of the evaporator water inlet (such as during the hot summer) to avoid a possible high
pressure alarm event.
The function si managed through an analogue input configured as NTC evaporator water inlet and, when active, reduces the number of
steps according to the value of the CO46 parameter.
24.2 UNLOADING DESCRIPTION
UNLOADING ACTIVATION
The function is active in chiller mode, when the evaporator water inlet is equal or bigger than the CO34 setpoint for the CO36 time.
When the unloading is active the display shows the AEUn blinking message alternated with the selected display measurement; the unit
will start with the loads selected with the CO46 parameter.
UNLOAD DEACTIVATION
If the temperature decreases under the value determined by (CO34-CO35) parameter, the unloading is disengaged and all the
compressors are available for the thermoregulation.
24.3 UNLOADING INFORMATION
If the evaporator inlet temperature is lower than CO34 but higher than CO34-CO35, to avoid a prolonged working time in unloading
status, a timer is activated to disable the unloading function.
This time starts when the evaporator inlet temperature is lower than CO34 and, when elapsed, the unloading function is disabled.
24.4 UNLOADING WITH PRESSURE / CONDENSING TEMPERATURE OR EVAPORATING
PRESSURE CONTROL
The function is always enabled for both chiller and heat pump mode in order to reduce the load and helps the unit to start: in chiller for
high temperature of the external air (to avoid high pressure alarms), in heat pump for low temperature of external air (to avoid the low
pressure alarms).
The compressor unloading in chiller mode is managed by the analogue input configured as condenser probe circuit 1 or 2 and
determined by CF07 (0=temperature, 1 = pressure).
The compressor unloading in heat pump mode is managed by the analogue input configured as evaporator probe circuit 1 or 2.
If the application has only one condendenser, to guarantee the right operation of the unloading is necessary to configure both
condenser probes/trasducers, one for each circuit.
24.5 REGULATION IN CHILLER MODE
ACTIVATION IN CHILLER MODE
When the condenser pressure/temperature is equal or bigger than CO41 setpoint the unloading process is engaged. The bottom display
shows, alternated with the measurement, the b1Cu or b2Cu labels (depending of the circuit involved). When the function is active, the
number of working compressors/step is determined by the CO46 parameter.
DE-ACTIVATION in CHILLER MODE
If the temperature decreases under the value determined by CO41-CO42 (setpoint – differential), the unloading is disengaged, the
compressors are all available for the thermoregulation.
OTHER INFORMATION ABOUT THE UNLOADING IN CHILLER
If the condenser pressure/temperature is higher than CO41 but lower than CO41-CO42, to avoid a prolonged working time in unloading
status, a timer is activated to disable the unloading function.
This time starts when the evaporator inlet temperature is higher than CO41 and, when elapsed, the unloading function is disabled.