Professional Member*
I don't know why it stopped tripping on oil pressure but I am glad it did. Nothing changed that I can see so it remains a mystery. Indy what do you mean by I should have seen it after 10 mins of run time? All of the safeties (high pressure, low pressure, oil pressure and motor over load protector) are wired in series with the contactor coil.
Last edited by welling service; 11-30-2012 at 11:18 PM. Reason: add a word
Professional Member*
You should have seen the drop in net oil pressure, with in ten minutes.Originally Posted by welling service
I don't believe the oil press suddenly dropped as soon as you left.
If the compressor goes off on internal overload the oil fail will trip.
When the overload condition automaticcaly resets, the manual reset of the oil fail is needed.
Same for a brown out.
Professional Member*
I did see a drop in net oil pressure within 5 mins. from about 50 psi down to 15 psi. You might have something on the internal overload thing. Haven't thought of that but the comp. never runs hotter than normal. I should have checked amp draw but never saw any reason too.
Professional Member*
was the oil Gage fluttering?
if there is refrigerant boiling out of the oil, you would see lower and possibly flutter in net oil pressure.
Last edited by indy2000; 12-01-2012 at 05:00 PM. Reason: spelling
Professional Member
If the oil failure control is powered through a current sensing relay, it will not trip on an internal overload/brown out condition.
Professional Member*
No flutter in gage on oil pump port or CC pressure gage. No foaming in oil sight glass. Oil level remains fairly constant at 1/4 glass. Thanks for all of the suggestions. I still think it is a bearing problem. Two reasons I say this; 1. Oil pump pressure at comp start up=85 five mins or less into run=40 psi. Suction pressure=25psi and varies depending on how many LLSV's are calling. There are a total of 6 LLSV's on this system. 2. The sister comp which I just installed never drops in NPOP and they share a common hot gas and suction line. I replaced it because of bearing failure. The previous had jumps red the oil pressure controls. That was his way of solving problems. It just seems to me if there was an external reason for the comp. tripping on oil pressure it would be happening to both comp.
Professional Member*
sounds like an oil return return problem, seeing you have lost a compressor already.
you def want to get to the root problem, could be a piping issue.
Professional Member*
r&r'ing a 40hp semi on monday, apparently the 4th in 3 years.
Will be many hours of investigation before this one is left on its own, lack of lube.
good luck with yours.
Regular Guest
replace contactor! oil pressure is fine, one leg of contactor is bad, overload opens before the oil pressure switch, when you get there you manually reset oil, but the overload closed long time b4.
Regular Guest
i sort of have the same problem with my TRANE 6 cyl. model E (open type) overhauling it right now i noticed a scratch on the oil line going to the seal end bearing but did not notice any problem with the bearings...could anyone help me on what to do with the scratch or should i just ignore it..i maybe off the topic sorry i am new to the forums
Professional Member
what do you mean by a 'scratch' on the oil line...on the copper line?
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Professional Member*
What made the scratch? Is it deep enough to allow oil to escape? My copeland just quit tripping out on oil pressure and I don't know why. Once the weather cooled off a little it stopped tripping. I can't see any correlation between cooler weather and the problem with oil pressure. I never saw abnormal head pressure or suction pressure. It never ran hot so I can't see it going out on internal overload or high temp. The only abnormal thing I witnessed was a drop in actual oil pump pressure out put a few minutes after start up. Which leads me to suspect an internal oil leak.
Last edited by welling service; 12-20-2012 at 10:44 PM. Reason: correction
Regular Guest
yes sir that 1/4inch line that is coming from the oil pump it is not that deep though just need advice if i should go and weld it up thanks
Regular Guest
i think it was from a previous failure though it has a scratch on the oil line no evidence from the bearings that i took out and replace that i lacked lubrication,,it is not deep enough for the oil to escape as per my inspection i need your opinion can i use metal epoxy to patch it up or just simply leave it as it is thank you sir for the reply
Professional Member
Since you do not have a picture, it is difficult to say. I would lean toward replace versus epoxy repair. If the scratch looks old and you aren't having any issues then it might be best to leave it alone.
Regular Guest
yup from the looks of it.. it is old since there were no large chunks of parts that broke that might have scratched it. anyways thank you very much and will post here whatever happens
Regular Guest
well i started the compressor last night it went great i had 60psi back pressure an oil pressure of 140psi and a head of 250psi thanks for the advise my friends
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