Dear Sean, Ranger,

This is a basic tandem compressor application. 2 compressors for each circuit. circuit is constructed from shell and tube evaporator, comressor(2 x scroll tandem) checkvalves on each compressor outlet(we checked the checkvalves nothing wrong on them, no restrictions) - condenser, liquid line valve-dryer -liquid line valve and electronical expansion vavlve. The subcooling is read on dryer inlet, the pressure is read for subcooling on dryer inlet. All instruments are calibrated(from testo). the anomaly is the pressure losses on the dryer and the condenser thats the thing i cannot understand the reason. We cannot increase the subcooling even charging extra refrigerant. We observe that the discharge pressure rises, subcooling does not improve even so.