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USER MANUAL – Release 1.2 of 01/01/2010
Page 119 of 191
Version: 02/03/2010
0= remains at automatic reset even if the number of interventions/hour are reached
1=enables manual reset on reaching the number of interventions/hour
45. CIRCUITS UNLOADING
It manages the forced partialisation of the cooling circuits when the unit is working in critical working
conditions. This function manages the partialisation due to overloads of cooling and heating units with a
maximum of 4 cooling circuits, in a way to guarantee a continuity of service even in the most heavy duty
conditions.
The unloading can be activated on all circuits due to high/low water pressure or individually on the circuit of
interest for high condensation pressure/temperature, for evaporation low pressure.
FUNCTION ACTIVATED IN COOLING MODE
Compressor unloading is managed by means of the analogue input configured as circuit n° 1 condensation
probe or circuit n° 2 condensation probe (according to the value set in Par
CF07=0
temperature
1
= control in
pressure mode).
With the working state selected by compressors ON request, if the condensation pressure/temperature is the
same as or exceeds the CO44 set in cooling, the circuit unloading function is activated to which the
transducer/NTC belong. Only the steps selected with par. CO49 remain inserted (with function inserted on
the lower display the
b1Cu or b2Cu
label flashes alternately to the variable measured).
FUNCTION DEACTIVATED IN COOLING MODE
If the condensation pressure or temperature drops below the CO44 – the CO45 diff. set in cooling mode, the
function is disabled.
When the condensation pressure/temperature drops below the CO44 set in cooling mode, the time set in
Par. CO48 is counted. When this has expired, the function is disabled even if the pressure/temperature has
not dropped (set – diff cooling).
FUNCTION ACTIVATED IN HEATING MODE
Compressor unloading is managed by the analogue input configured as circuit n° 1 evaporation probe or
circuit n° 2 evaporation probe.
With the working state selected by compressors ON request, if the condensation/evaporation pressure is the
same as or lower than the CO46 set, the circuit unloading function is activated to which the transducer/NTC
belong. Only the steps selected with par. CO49 remain inserted (with function inserted on the lower display
the
b1Cu or b2Cu
label flashes alternately to the variable measured).
WARNING:
if the temperature/pressure stays the same or less than the activation set, the function is ALWAYS inserted
If compressors are used with partialisation steps, in the case of working in unloading mode, to prevent
swings inside the circuit, once a step is inserted (partialisation valve in ON) this step remains activated for a
minimum time set in the Par. CO50, even if the unloading condition returns and 100% working is requested.
If the Par. CO50 is set at 0; the function is disabled and if the unloading condition returns and 100% working
is requested, the partialisation is deactivated immediately.
FUNCTION DEACTIVATED IN HEATING MODE
If the evaporation pressure rises above the CO46 + the CO47 differential set, the function is disabled.
When the condensation/evaporation pressure rises above the CO46 set, the time set in Par. CO48 is
counted. When this has expired, the function is disabled even if the pressure/temperature has not risen
above (set – diff heating).
45.1 UNLOADING FROM CONDENSATION HIGH TEMPERATURE PROBE
The high temperature unloading function is active in cooling and heating units.
The function is managed by means of the analogue input configured as circuit condensation high
temperature NTC probe
FUNCTION ACTIVATED:
If the temperature measured by the condensation probe is equal to or exceeds the set for a time that can be
set, the unloading function of the circuit to which the probe belongs is activated. The power available is
managed via the parameter chosen of the steps to be inserted into the circuit.
FUNCTION DEACTIVATED:
