Carel uC2SE, User Manual

Page: 54 / 76

54
r01 r01 + r29
on
off
r01 r01 + r02
on
off
r03 - r04 r03
on
off
r03 - r30 r03
on
off
1 2
3
5 5
5 5
4
r32-r33
hoot keep hoot start
r32
ON
OFF
1
2
ENGLISH
μC 2 SE - +030220426 - rel. 2.1 - 09.06.2010
- Cooling set point in dehumidifi cation
r26:
Alternative set point to r01 when the dehumidifi cation function is active, as sent to the
μC2SE by the terminal.
The diff erential remains the same as for chiller mode (r02).
- Buff er tank suppression (low load)
r27:
The low load condition is determined when only one compressor is started and then is
stopped after operating for less than the time set for parameter r28.
The settings are:
r27=0: the function is disabled;
r27=1: enabled only in chiller mode;
r27=2: enabled only in heat pump mode;
r27=3: enabled in chiller and heat pump modes.
- Minimum compressor on time to determine low load condition
r28:
This parameter represents the minimum compressor on time below which the low load
condition is determined. Whenever the compressor stops, the controller analyses the load status.
If already in low load condition, the time considered by the controller for the analysis becomes
“r28 x r29: r02” in chiller mode, or “r28 x r30 : r04” in heat pump mode.
This parameter also has the meaning of damper travel time when freecooling/heating is enabled.
When the sum of the opening times reaches 2*damper travel time, the damper is no longer
moved. The sum is reset when the damper is closing. Operation is the same in closing.
- Diff erential during the low load condition in chiller mode
r29:
This parameter represents the new diff erential considered by the controller in chiller mode
during the low load condition.
Specifi cally, r02 is replaced by r29.
This also has the meaning of freecooling diff erential.
- Diff erential during the low load condition in heat pump mode
r30:
This parameter represents the new diff erential considered by the controller in heat pump
mode during the low load condition.
Specifi cally, r04 is replaced by r30.
This also has the meaning of freeheating diff erential.
Fig. 5.b.m
Fig. 5.b.n
Key:
1. chiller;
2. chiller in low load;
3. heat
pump;
4. heat pump in low load;
5. temperature.
- Heating compensation constant (mode Heat pump)
r31:
Sets the coeffi cient that controls the heating compensation algorithm. In heating mode,
if r31 is positive, the set point decreases as the outside temperature decreases (measured by
the outside probe); if, on the other hand, r31 is negative, the set point increases as the outside
temperature decreases. This maximum deviation of the set point from the set value is equal to
parameter r18. See, for example, parameter r17.
- Set point B2 in hot start
r32:
The fan, after reaching the hot start set point, cannot be stopped if at least one compressor is
on or the electric heaters are operating.
- Hot start diff erential
r33:
Hot start diff erential
Key:
1. outlet fan;
2. probe B2.
Fig. 5.b.o
Hot keep/hot start example