1592015820 User manual IC260_261L_D DUO FW1.9 rel. 1.0
Pag. 82 of 149
When the condenser temperature/pressure or evaporating pressure falls below dF02 and at least one
compressor is ON, the delay between two defrost dF09 starts counting.
The display of the keyboard shows the symbol
blinkking.
dF09 counter is reloaded in case of
power down, after a defrost cycle, when the Ichill change the operation
mode (from heat pump to chiller) or when the Ichill is in STD-BY or remote OFF.
dF09 counter is stopped if the last compressor of the circuit is turned off or if the pressure-temperature of the
condensing-evaporating probe increase over dF02.
Phase 2
When dF09 counter is elapsed the defrost procedure starts.
If one digital input is configured as “end defrost” is active, the unit waits until the contact is de-activated.
If one probe is configured as combined defrost:
If the combined defrost probe of the 1
st
circuit is lower than dF10 and/or the combined defrost probe of
the circuit 2 is lower than dF12, the process proceeds to phase 3.
If the combined defrost probe of the 1
st
circuit is higher than dF10 and/or the combined defrost probe of
the circuit 2 is higher than dF12, the process doesn’t proceed to phase 3
Phase 3
If dF07=0 the reversiong valve is activated without stopping any conmpressor and the defrost cycle is
immediately activated.
If df07>0:
1. Compressors are turned off
2. After dF07 / 2 the reversing valve is activated;
3. After dF07 / 2 the compressor is activated; if dF14=1 and / or dF15=1 all the compressor are activated
(with a delay of dF16).
Phase 4
Defrost ON
Condenser fan management:
If dF17=0: condenser fan are always off;
If dF17=1: condenser fans start if the condensing temperature-pressure value is higher than dF18 and
the regulation is the standard chiller regulation.
ATTENTION
The condenser fan is controlled by the condensing probe even if the evaporator probe is present and
configured.
The phase 4 lasts at least dF04 time; phase 4 ends:
1. If dF01=1:
the combined probe is higher than dF11 of the 1
st
circuit;
the combined probe is higher than dF13 of the 2
nd
circuit;
when the condensing temperature/pressure is higher than dF03
2. If dF401=2: when dF05 counter is elapsed
3. If dF01=3: when the digital input configured as end defrost is deactivated
PHASE 5
If dF08 = 0 the reversing valve is switched without stopping the compressors and the defrost ends.
If dF08 > 0:
1. All the compressors are switched off
2. After dF08 / 2 reversing valve is de-activated
3. After dF08 / 2 the heat pump regulation can restart
40.2 Other Information About The Defrost
If the unit is configured with one condenser FA05=0, the defrost of the two circuits starts at the same time.
ATTENTION
Before starting the 3
rd
phase, the dF06 counting, time delay between two circuits defrost, must be expired.
If the defrost ends because of the dF05 counting (Maximum defrost time) and the dF02 configuration or with
the end defrost contact, the bottom display will show, alternated with the normal measurement value, the
label
b1dF
(circuit #1) or
b2dF
(circuit #2) labels to indicate the defrost end alarms.
