Hyrovane 25 (3 phase prob)

[Bigvtwin996]

ok have a 3 phase Hydrovane 25 sitting on top of a tank.....
Dol start with std style pressure switch...
really nice and quite if all I need to do is some bead blasting....

All was great till we had a cold snap a week or two ago.....
Fires up... got up to pressure cut out..... pressure dropped and didn't cut back in...
off on off on.... nothing

left for 1-2 hours push the green start button away we go.... but stops at 70psi
1 -2 hours push the green button away we go ... stops... nothing....

Well today (much warmer in the uint)
push the button -----> 150psi cuts
drops... does noit cut back in...

Suggestions on a postcard or post on here if it may help anyone else...
(my thoughts are the pressure switch has gone wonky just after a second opinion before I chage my xmas present list or i could waste my time and strip one from the boom bang a bang piston compressor)

 

[carbon]

I’ve seen a pressure switch fail in the last week on customers compressor it started but wouldn’t switch off correctly. When it did switch off it wouldn’t restart even when the receiver was empty. I took the cover off the switch and found a spring had broken.

 

[knighty]

yep, sounds like the pressure switch.... try knocking it when the compressor should be on/off and isnt.... see if it starts/stops like it should :-)

 

[JimmyS]

Sounds like pressure switch. We used to stick a screwdriver under the bellows if not cutting in, staying clear of the electrics, to start motor to see if pressure switch was playing up. otherwise check voltage over contacts with a meter?

 

[Brad93]

They can seize if not enough oil in them

 

[Bigvtwin996]

had a look at the switch innards... don't see anything uusual... could be sticking..
checked oil....
over xmas will scavange the pressure switch of the other compressor and planned an oil change any way....