Hi Guys/Girls,

Is there anybody out there able to give some advice on a Star pack, circ 1990. The pack consists of 2 off Howden WRV 163 compressors and drive motors, economised and thermosyphon oil cooling. Each compressor runs fine on its own but as the lag machine comes in it fails on high discharge pressure. The system is LPR and NH3 is the refrigerant.We thought it might be oil logging and/or a stuck NRV in the discharge but these have been checked and all is fine. We have also checked the oil injection solenoid valves, again all is Ok. Any ideas??
Any advice would be appreciated

Frosty