Carel uC2SE, User Manual

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μC 2 SE - +030220426 - rel. 2.1 - 09.06.2010
- Antifreeze/low room temperature (air/air) alarm diff erential
A02:
This represents the diff erential for the activation of the antifreeze alarm (low room
temperature in air/air units); the alarm condition cannot be reset until the temperature exceeds
the set point + diff erential (A01+A02 or A14+A02).
- Antifreeze alarm bypass time low room temperature from unit start in heating mode
A03:
This represents the delay in the activation of the antifreeze alarm when starting the system.
In the case of air/air units, this parameter represents the delay time for the low room temperature
(return-intake air) signal, only in heating mode. This means that the room being heated is too cold
(threshold set by the user).
- Antifreeze heater/auxiliary heater set point in cooling
A04:
Determines the threshold below which the antifreeze heater is switched on. In the air/air
units (H01=0, 1) this parameter represents the temperature value below which the auxiliary heater
is activated. This temperature is compensated according to the following equation:
Set_heaters (cooling)= A04+(Compensated set point – Set point set)
In the air/air heat pumps (H01=1) the auxiliary heaters are not used in cooling mode.
N.B. The antifreeze set points are not compensated.
- Antifreeze heater/auxiliary heater diff erential
A05:
Diff erential for the activation and deactivation of the antifreeze heaters (auxiliary heaters in
air/air units).
Operating diagram of the antifreeze alarm and the antifreeze heaters for air/water and water/
water chillers and heat pumps.
Key:
1. antifreeze alarm diff eren. (A2)
2. antifreeze heater diff eren (A5)
3. heaters
4. antifreeze
alarm
5. antifreeze heater set point (A4)
6. antifreeze alarm set point (A1)
- Auxiliary heater probe in heating
A06:
This determines which probe is used for control the auxiliary heater. The meaning of the
parameter is the following:
A06 = 0 => Control probe see Table 5.a.a
A06 = 1 => Antifreeze probe see Table 5.a.a
If H1=1 the heaters are disabled in cooling mode. See Functions of the probes.
Not valid if A10= 2
- Antifreeze alarm set point limit
A07:
Establishes the minimum limit for setting the antifreeze alarm set point (A01).
- Antifreeze heater in defrost/auxiliary heater in heating set point
A08:
Represents the threshold below which the auxiliary heater is ON in defrost and in heating
mode.
The set point in heating is compensated according to the following equation:
Set_heaters (heating) = A08+(Compensated set point – Set point set)
The antifreeze set point is not compensated.
In the heat pumps (H01=1-3-6), during heating mode, it represents the set point for the auxiliary
heater; during the defrost cycle, it represents the set point for the activation of the antifreeze
heaters. In the air/air units (H01=0) it only represents the set point for the heating heaters.
In heat pump mode (H1=5-10) this represents the set point for the antifreeze heater and the
antifreeze probe becomes B3/B7
- Antifreeze heater/auxiliary heater diff erential in heating
A09:
Represents the diff erential for the activation/deactivation of the antifreeze heater in defrost/
auxiliary heater in heating. The diff erential is the same for both heaters.
- Automatic start for antifreeze
A10:
This parameter is valid when the unit is in standby.
The operating mode switchover delay times are ignored.
A10=0: function not enabled
A10=1: Auxiliary heater and pump are ON at the same time, based to the respective set: points,
A04 or A08, according to the settings of the antifreeze or auxiliary heaters; the exception is when
H01=1 in cooling, in which case not even the pump will be activated. Each circuit, in the case of
two evaporators, will be controlled based on its own probe (B2, B6).
A10=2: pump and auxiliary heater ON independently based on the respective set point, A04 or
A08. If the temperature falls below the antifreeze alarm set point A01, the unit is started in heating
mode, controlling the steps (compressors) based on the set point A01 and diff erential A02, in
proportional mode. Each circuit, when there are 2 evaporators, will be controlled using its own
probe (B2, B6). A10=2: pump and support heaters activated together, based on the set point A04.
If there is an alarm in both circuits, control will be performed on the based on the lower of the
two. This mode ends automatically when the antifreeze set point A01 + the diff erential A02 is
reached (returning to the previous mode); in any case, the function can be terminated manually
by modifying the parameters or disconnecting the power supply to the device.
CAREL NTC probe (mode H1= 2, 3, 4, 5 and 6)
Fig. 5.a.b