Carel µC2SE

41
ENGLISH
µC
2
SE - +030220426 - rel. 2.0 - 03.08.2009
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 fl ow 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
compressor 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
temperature 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.
- Start defrost with 2 circuits
d15: This parameter is used to select whether to defrost the two circuits together or separately.
d15 = 0 (default): the two circuits start defrosting independently (each according to their own
temperature or pressure probe reading), only if H2=1;
d15 = 1: the two circuits start defrosting when both have reached the start defrost conditions;
d15 = 2: the two circuits start defrosting when at least one of the two has reached the defrost conditions.
d14= 0 d14= 1 d14= 2
d15= 0 OK OK OK
d15= 1 OK OK OK
d15= 2 Not possible OK Not possible
Tab 5.b
- Forced ventilation time at end defrost
d16: If the parameter F13 = 2, as soon as the end defrost temperature or pressure is reached, the fans are
activated at maximum speed for the set time, before the change in operating mode.
Only at the end of this time will the cycle switch back to heat pump mode, with the normal management
of the fans.
- Defrost with compressors OFF (Fan Defrost)
d17: This function allows the outside temperature to be exploited, when suffi cient, to defrost the
condenser (outdoor evaporator).
In these conditions, the unit, rather than reverse the cycle, simply turns OFF the compressors and
activates the fans at maximum speed.
The start and end defrost conditions remain unchanged, as does the use of any auxiliary heaters.
The parameter has the following settings: d17=0: function disabled, d17>0: function enabled with relative
set point (which represents the minimum defrost temperature set by the manufacturer). Above the set
point, the unit performs the Fan Defrost.