High Pressure Unloading - Lennox CLIMATIC 50 User Manual

HIGH PRESSURE UNLOADING

Function
Reduce the capacity of a refrigeration circuit before the HP cut out is reached
Description
High Pressure Unloading consists in reducing the variable capacity on a screw compressor, or to stop one
compressor on units fitted with tandems or trios.
Activation of High Pressure Unloading
If High Pressure is over 26.5 bars (Ecologic, MCC with scroll compressors) or 23.5 bars (other units) and
carries on increasing as all the fans are running full speed, one compressor is stopped, or one stage of
capacity reduction is activated on the affected circuit.
High Pressure Unloading is controlled as an additional virtual ventilation stage while the HP is over the
threshold. See explanation in the fan control section.
CLIMATIC 50 user manual – Chillers ranges CL50-CHILLERS/IOM/1105-E
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