OROAB 5-210 R407C on Liebert Remote Condenser.

[gwoner]

OAT 8*. head pressure control making a loud vibrating noise. Is this a sign of internal damage to the valve or diaphram or is it common at this low of ambients

[trippintl0]

I have no experience with that particular valve, but two of my supervisors have told me of instances where a ridiculously loud noise was found to be coming from a headmaster.

[2sac]

I would say yes. Have seen it once on a Hoshizaki IM. Replaced valve, noise is gone.

[indy2000]

i've heard noise come from them on start up or pump down, what is the discharge and liquid pressures at?

[gwoner]

Just shut down ckt 1, to dang cold out with windchill at -17* f. Will return at end of week to investigate. Customer happy and occupants in office below condenser happy with noise gone .