Carel µC2 User Manual

37
E N G L I S H
µC
2
- +030220731 - rel. 1.2 - 26.10.2007
- Minimum defrost duration
d06: Represents the minimum duration of the defrost cycle (the defrost continues even if the value read
by the condenser probe exceeds the end temperature/pressure). If set to 0, the minimum defrost time
function is disabled.
d06=0: control disabled.
- Maximum defrost duration
d07: If timed defrost is set (d02=0), this establishes the duration of the cycle.
If, on the other hand, the defrost ends at a set temperature/pressure, it represents the maximum duration
(being in this case a safety feature, an alarm is signalled, “dF1” or “dF2”).
- Delay between two defrost requests in the same circuit
d08: Represents the minimum delay between two successive defrost cycles.
- Defrost delay between the 2 circuits
d09: Represents the minimum delay between the defrost cycles on the 2 circuits.
- Defrost management from external contact
d10: This enables or disables defrost control from an external contact.
This function is typically used to end the defrost based on a signal from a thermostat/pressure switch
connected to the corresponding digital input. In this case, the defrost times are ignored.
d10 = 0: function disabled.
Note: for the other settings, the start and end defrost are enabled for temperature and pressure values
between the Defrost start and end set points
d10= 1: start defrost from external contact enabled therefore:
if the contact of the input is open, the start of the defrost is enabled;
if the contact of the input closed, the defrost follows the normal procedure.
d10= 2: end defrost from external contact enabled therefore:
if the contact of the input is open, the end of the defrost is enabled;
if the contact of the input is closed, the defrost follows the normal procedure.
d10= 3: start and end defrost from external contact enabled therefore:
if the contact of the input is open, the end/start of the defrost is enabled;
if the contact of the input is closed, the defrost follows the normal procedure.
- Antifreeze/auxiliary heaters in defrost
d11: This parameter determines whether, during the defrost cycle, the antifreeze/auxiliary heaters should
be activated to limit the flow of cold water/air into the room.
d11 = 0: antifreeze/auxiliary heater not activated in defrost;
d11 = 1: antifreeze/auxiliary heater activated in defrost.
- Waiting time before defrost/delay in switching from heating to cooling
d12: As soon as the defrost condition arises, but before the actual cycle starts, the unit stops the compres-
sor for the time d12 (selectable from 0 to 3 minutes). When the compressor stops, the four-way valve
is switched (reversing of the cycle), after a time equal to d12/2; this waiting time allows the pressure to
balance before starting the defrost cycle. In this procedure the compressor protection times are ignored,
and consequently the compressor is stopped, and subsequently restarted, immediately.
If d12=0, the compressor is not stopped and the reversing valve is switched immediately.
- Waiting time after defrost/delay in switching from cooling to heating
d13: At the end of the defrost cycle, the unit stops the compressor for a time d13 (selectable from 0 to
3 minutes). When the compressor stops, the four-way valves is switched (reversing of the cycle), after a
time equal to d13/2; this waiting time allows the pressure to balance and the outdoor coil to drip. In this
procedure the compressor protection times are ignored, and consequently the compressor is stopped,
and subsequently restarted, immediately.
If d13=0, the compressor is not stopped and the reversing valve is switched immediately.
- End defrost with two gas circuits/1 fan circuit
d14: This parameter is used to select, in units with two refrigerant circuits and one fan circuit, the end
defrost mode.
d14 = 0 (default): the two circuits end the defrost independently (each according to their own temperatu-
re or pressure probe reading), only if H2= 1;
d14 = 1: when both the circuits have reached the defrost condition;
d14 = 2: when one of the two circuits has reached the end defrost condition.
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Carel µC2 Specifications

General

Brand	Carel
Model	µC2
Category	Controller
Language	English