Dunham Bush Chiller Alarm

[Regulator]

This is a question for any body that can help clear my confusion on a Low Oil Pressure Diff. Alarm on a Dunham Bush Chiller, Mod # IPCX 350-HFALXNP-Q.

The alarm setpoint is 25 psig. It shuts down the Chiller and after the chiller is reset, the Diff. oil pressure starts about 42 then drops as the compressor loads up. Once it gets up to about 95% loaded it has dropped back to about 26-27 psi, then eventually after a couple hours drops below the 25 psi Low Differntial setpoint and shuts down in alarm.

I would understand if it was a high Diff. that it might be the filter. But I can't even find a high Differential setpoint on the chiller screens. Is the low diff. alarm concerning the filter? does it mean that maybe the filter is open, damaged?

I am the Operator at this time on this equipment and any advice would be appreciated. Also material on the chiller is hard to come by aparently, any advice on that would be appreciated also. Thanks...