Oil pressures

[N.Lewis]

Hi guys, Have a system tripping out on low oil pressure.
But when unit running,oil temp is 40.2degC
And oil pressure is betwen 4.5 & 5.5bar.
Thinking i could have a dodgy sensor???

[Gary]

Something else to look for:

Some systems are wired such that the oil pressure switch can be energized when the compressor trips on internal overload. Then the overload resets itself, but the oil pressure switch does not.

This can make you think it is an oil problem when in fact it is a compressor overload problem (low voltage, undersized wiring, burnt contacts, loose connections, etc...).

Check the voltage at the compressor with the compressor running.

[taz24]

Hi guys, Have a system tripping out on low oil pressure.
But when unit running,oil temp is 40.2degC
And oil pressure is betwen 4.5 & 5.5bar.
Thinking i could have a dodgy sensor???

Hi

You say 4 to 5b oil pressure. Is that oil differential pressure?

If you have 5 b then pump seems ok but you say sensor! What type of oil switch is it because some
measure the difference in pressure and some use sensors. If it is electronic then yes the sensor or the switch could be faulty.

We need more informations.

taz.

[PaulZ]

Another thing you may want to check is that the oil failure switch is last in the safety control circuit. If the LP cutout is after the OFS every time the compressor shuts down on LP it will trip the OFS. Paul

[N.Lewis]

Hi guy's, as always thanks for all prompt replies and helpfull information, sorry it's taken so long to reply.
To keep you posted, have replaced the oil pressure switch and sensor, unit is now running-cutting in and out.
Again thanks to everyone.
Nick.