Carel µC2SE User Manual page 47

- Capacity-control logic
H12: Specifi es the logic for the activation of the capacity-control steps for the compressors and the 4-way
reversing valve.
H12 = 0: 4-way reversing valve and capacity-control normally energised
H12 = 1: 4-way reversing valve and capacity-control normally de-energised. Default value.
H12 = 2: 4-way reversing valve normally de-energised and capacity-control normally energised
H12 = 3: 4-way reversing valve normally energised and capacity-control normally de-energised.
Note: in the event of capacity-control, the rotation between compressor and corresponding valve is disabled.
FIFO or time logic can be used between the 2 circuits to optimise the starts or the operating hours of the
2 compressors (1 per circuit).
- Enable pump down
H13: This function allows the unit to be stopped while avoiding the possible formation of liquid refrigerant
inside the evaporator.
When the only active compressor is called to stop, the expansion valve is closed so as to depressurise the
circuit.
Valid only when the driver is installed, as the driver pressure probe is used.
- Minimum pumpdown pressure
H14: Limit pressure below which the compressor is deactivated.
- Maximum pumpdown time
H15: Maximum time after which the compressor is deactivated.
- SmartSET "CAREL patent" (cannot be used on air/air units)
H16: Activate smartSET, this function optimises the operation of the unit by calculating the effi ciency of
the heat exchangers.
In smartSET mode, the following values are saved:
• Only when R06= 0 or 4;
• DTE: difference between evaporator inlet temperature (B1) and outlet temperature (B2/B5), calculated
at full load (all compressors on) when reaching the user set point. Saved to memory on the E2P;
• DTC 1: difference between outside exchanger temperature (B3) and outside temperature (B4,....) (this
implies the confi guration of a dedicated probe, optional setting). It is calculated whenever condenser fan
1 runs at maximum speed for 30s, irrespective of the status of the compressors;
• DTC 2: (calculated only when there are 2 condensers) difference between outside exchanger temperature
(B7) and outside temperature (B4,....) (this implies the confi guration of a dedicated probe, optional
setting). It is calculated whenever condenser fan 2 runs at maximum speed for 30s irrespective of the
status of the compressors.
With proportional inlet control, the dynamic set point (STD) and the corresponding proportional band are
adapted according to the DTE.
With outlet control and dynamic logic, that is, dead zone and activation/deactivation times, the dead zone
has a dynamic value.
In this case too, control will be optimised according to the actual DTE measured.
- Minimum DTE value allowed
H17: Even if there is not danger involved, beyond the limit a warning is sent ("dEL") to check the water
fl ow-rate, which is perhaps too high, or low condenser effi ciency.
- Maximum DTE value allowed
H18: Maximum value allowed for DTE, above the limit the evaporator risks freezing, the anomalous
behaviour is signalled by "dEH".
- Maximum DTC value allowed
H19: Maximum value allowed for DTC, above this value the condenser may be dirty (chiller) or dirty/frozen
(heat pump).
µC 2 SE - +030220426 - rel. 2.0 - 03.08.2009 47