Sullair C25SB

[Winchester]

This is a booster compressor that runs at 12" and the problems is that on start up it fails on low oil pressure. It does biuld oil pressure. What I have noticed is that the oil and discharge pressures equalize to suction pressure went it's off so when it starts it times out on low oil pressure. I have changed oil pump check and oil injection to male and female rotor. Any insight would be greatly appreciated. Thanks

[Sullair Refrig]

When idle it is not abnormal for the complete package to be at suction pressure.
My first question is the oil strainer clean that supplies the oil pump? It is probably a 1-1/2" Y strainer unless it has the optional dual basket style. Your oil level should be in the middle of the top sight glass, you should have 3, at the bottom of the oil separator.
You can contact me at dan@midstatesrefrig.com

[RANGER1]

If the package is in a vacuum on start up it may be difficult difficult for pump to prime properly , maybe this is the case ?
On some sullairs the pump stops once timed out to give chance for pressure differential to take over oil feed .
Oil pump pre filter as suggested and main oil filter could be checked as well .
Is oil seperator oil heater working when compressor idle ?

[nh3wizard]

We had a similar problem with our Sullair and it was the strainer, it was clogged. Once we cleaned it it ran fine.