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USER MANUAL – Release 1.2 of 01/01/2010
Page 129 of 191
Version: 02/03/2010
WORKING OF THE BOILER HEATERS DURING THE DEFROST CYCLE
The parameter Ar05 establishes working of the boiler heaters (anti-freeze)
during
the defrost cycle. If the
value is 0 during the defrost cycle the heaters are only activated by their temperature control. If the value is
1, the heaters are always on during the defrost cycle:
they switch on when the reversing valve converts working from heating to cooling and they switch off when
the dripping time has ended and the compressor re-starts.
WARNING
The heaters in boiler working mode are off:
with a flow switch alarm active
with 1 evaporator water pump configured with water pump circuit breaker alarm active
with 2 evaporator water pumps configured with water pump circuit breaker alarm active and neither of the
two water pumps are available
(in this case the boiler heaters are only activated by the anti-freeze set to protect the evaporator)
48. ANTI-FREEZE HEATERS WORKING FROM DIGITAL INPUT
The anti-freeze alarm and the circuit n° heaters relay output management takes place via the active digital
input configured as circuit n° anti-freeze alarm.
WARNING
It is not possible to command the circuit n° 1 heaters relay output with the digital input configured as circuit n°
2 anti-freeze alarm and vice versa.
It is however possible to command the relay outputs configures as heater relays if circuit n° 1/ 2 / 3 / 4 in
parallel via just one digital input configured as circuit n° anti-freeze alarm.
49. DEFROST FUNCTION
Defrost can only take place if the following necessary conditions are present at the same time:
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unit with heating
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dF01 is different to 0 = defrost enabled
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unit in heating working mode with at least on compressor running
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the evaporation/condensation probe must be defined (per circuit). If the evaporation probe/s is/are
defined in heating mode the start/end of the defrost cycle is managed on the basis of the configuration of
parameter
dF28
If even just one of the conditions is not satisfied, the defrost procedure will not take place.
FORCED DEFROST
The function is enabled if the parameter dF29 is different to zero. Allows to perform a forced defrost cycle if
the condensation or evaporation temperature/pressure remain below the dF30 set for time dF29. If during
the count of time dF29 the condensation or evaporation temperature/pressure rises above the dF30 set plus
the differential dF31, the time dF29 is reloaded.
THESE PHASES MUST BE CARRIED OUT IN SEQUENCE IN ORDER TO START AN AUTOMATIC
DEFROST CYCLE:
PHASE 1
: dF09 count DEFROST INTERVAL
This phase must always be performed (THERE MUST BE AT LEAST ONE COMPRESSOR RUNNING)
1.
The timer is reloaded at dF09
if there is a power cut or after having performed the defrost cycle or on
changing the working mode.
2.
The timer is interrupted
if the compressor switches off or if
the condensation or evaporation
temperature/pressure detected by the probe exceeds dF02.
3.
The timer decreases
if the temperature/pressure detected by the probe in dF28 is below the dF02 set
4. Pass to phase 2 when the timer resets.
PHASE 2
: check the cycle start conditions
1. If the defrost end external contact is active, wait for it to be deactivated
2. If the probe is configured as combined defrost NTC temperature
