User manual

1592022700 User manual iCHILL 200CX Rel. 1.0 22/04/2009
Pg.54/114
dF22=0 Yes not possible (ACF1) not possible (ACF1)
dF22=1 Yes Yes Yes
dF22=2 not possible (ACF1) Yes not possible (ACF1)
ATTENTION:
The configuration error ACF1 is displayed if the parameter value of dF22 and dF23 is not permitted.
33.7 AUTOMATIC DEFROST PROCEDURE
Phase 1: when the unit is working in heat pump mode and at least one compressor is running, if the condensing-evaporating
temperature or pressure is lower than dF02 value the counting of the delay time dF09 (interval defrost of the same circuit) starts and the
defrost led is blinking.
Functioning of the time counter:
1. The dF09 counter is reloaded if the power supply fails, after a defrost cycle and after the unit changes from chiller to heat pump.
2. The dF09 counter is stopped if the last compressor turns off or if the pressure-temperature of the condensing-evaporating probe
becomes higher than dF02 parameter value.
3. The counter is decreased if the condensing or evaporating temperature-pressure probe value becomes lower than the dF02
parameter value.
Phase 2: this phase starts when the df09 time is elapsed
If one digital input si configured as “defrost end” of the circuit 1 or 2 and the contact is active, the unit waits until the contact is de-
activated.
Probe configured as combined defrost NTC of circuit 1 or 2:
if the condensing or evaporating probe value of the 1
st
circuit is lower than dF10 and lower than dF12 for the 2
nd
circuit the process step
on the 3
rd
phase, otherwise the unit waits until the probe values decrease under dF10 and dF12.
If any of the probe is not configured as combined defrost NTC, the process steps on the 3
rd
phase.
When the circuit condition are satisfied to execute the 3
rd
phase the display shows the dEF1 (circuit1) and dEF2 (circuit2 ) labels.
FASE 3: inversion valve management (parameter dF07=compressor deactivation time before the defrost)
dF07=0: the valve is activated without stopping any compressor and the defrost cycle is immediately activated. If the thermoregulation
or the dF14 parameter require more compressors, the dF16 (on compressor delay during defrost cycle) is loaded.
If df07 <> 0 the compressors and the steps are turned off (the compressor/s led is blinking, the defrost icon is on); the steps are
described below:
1. all compressors are switched off
2. after dF07/2 delay the valve is activated;
3. after dF07/2 delay the compressors are activated.
If the thermoregulation or the dF14 parameters require to turn ON more than one compressor for circuit, the delay on time between the
compressors depends on the parameter dF16.
If the partialization/s are configured always OFF during the defrost cycle, the compressor is always 100%.
• if dF14=1 (all the circuit n°1 resources are forced to ON): during the defrost cycle the compressors and steps of the circuit n°1 are
ON while, if dF14=0 , compressors and steps are thermoregulated.
• if dF15=1 (all the circuit n°2 resources are forced to ON): during the defrost cycle the compressors and steps of the circuit n°2 are
ON while, if dF15=0 , compressors and steps are thermoregulated.
4
th
PHASE: Fan management during defrost
Parameter involved: dF17 (condensing fan management)
 If dF17=0: the condensing fan are always off;
 If dF17=1: the condensing fans start if the condensing temperature-pressure value is higher than dF18, they will following the
normal chiller thermoregulation algorithm.
ATTENTION during the defrost cycle, both for chiller and the heat pump modes, the fan are controlled with the condensing probe even if
the evaporator probe is present and configured.
The 4
th
phase lasts at least for the dF04 time counting and can terminate for these conditions:
1. If dF01=1:
 The combined NTC probe value is higher than dF11 of the 1
st
circuit;
 The combined NTC probe value is higher than dF13 of the 2
nd
circuit;
 When the condensing-temperature probe/s is/are higher than dF03 parameter value.
2. If dF01=2: the dF05 counting, maximum defrost timeout, is expired, step on 5
th
PHASE;
3. If dF01=3, if the end defrost digital input is deactivated, step on 5
th
PHASE.
5
th
PHASE: Inversion valve management (par. dF08= compressor deactivation time after the defrost)
If dF08 = 0 the valve is turned without stopping the compressors, the defrost ends and all the regulation restarts, the defrost led in
heat pump is off).
If dF08 <> 0:
1. All the compressors and steps are turned off (the compressor leds are blinking and the defrost led is on)
2. after dF08 / 2 the inversion valve de-activated
3. After dF08 / 2 all the regulation restarts and the defrost led in heat pump is off).