CVHE-032F with erratic oil

[boat racer]

Sometimes it starts and runs fine, with steady 20~25 net oil pressure and other times it looses pressure when the compressor starts and locks out ... other times the oil pressure gage flutters so wildly you can hardly see it for the first half hour or so ... building up from 15 to 20

Is the oil pressure regulator the likely culprit?

I don't know much about centrifugals, nor the history of this particular machine, its a new account to us ... Monday at 3:45pm was the first time I looked at it, but in general it appears to have been well maintained. The oil filter was changed last July.

I wanted to change the filter first, but ... for some reason there has been a run on FLR00928's in this area and there are none to be had at present.

Is anyone else having trouble finding a filter?

And if someone could point me to a service manual for these things it would be helpful ... we are probably going to be taking on a few more locations with them. I've never had to do anything significant on them and our other top guy hasn't worked on them in about 25 years ... probably about when this baby was new

[r404a]

boat

does the oil reg have a 4 bolt pattern? Is this chiller grey or beige? is the regulator the type that has two pipes leaving the tank and flared into a valve body that has a brass dome? Run that filter part number by trane parts and ask them to look for any notes regarding an alternate if yu have the physical space to do so. had an issue with the manufacture shorting trane on oil filters lately.
would try filter first, like you are thinking, but you may indeed have a regulator cutting up. the second type I mentioned is a good culprit for this issue. one another thing you could check is if your vent valve is working. put a gauge on the oil sump, watch the pressure in the sump at start up, which will probably be more positive than evap pressure, about a minute later, vent valve should open and pressure in sump should (drop lower) approaching evap pressure. ideally it should be lower, but not likely on an old one like that. good luck


r404a

[jcater8127]

I heard that the factory laid off alot of employees which put them behind with production. Having problems getting any oil filters for Trane. Hope the lit. helps.

[boat racer]

Thanks for the quick feedback. We already asked about alternates for the filter, they were out of every possible alternate. Sounds like someone at Trane really screwed up.

Here's a picture of what I'm looking at

[r404a]

they should have an alternate for that filter. those regulators had dome leakeage issues i believe.

r404a

[boat racer]

The first places we tried were out of the filter and the alternates. Found the filter and cleaned the eductor ... and switched the tower back to auto. Someone had it on hand & high speed. On the warm days the head pressure was normal, but on the cooler days it was low 'cause the tower water was only 70° duh.

Now I'm having trouble with the bypass valve hanging up ... sometimes. The valve itself has threaded fittings but the other piping is brazed. Seems stupid to have to recover the charge to replace that valve. It would have been better if it had at least one flange I could unbolt so I could spin the other side and not have to braze anything.

Its got me thinking of using some kind of stopper and brazing in a flange fitting. I might try just replacing the guts of the valve unless I see actual wear on the housing.

[pete_d]

FLR1592 can replace FLR928. It is longer but same diameter and thread.

[r404a]

boat

good truble shooting. looks like you have standard flares, not inverted. how about pressurizing to 0, pull and cap with flare plugs and put a new reg in. have been burnt before trying to get one apart to rebuild and it leaked to hell when it was tightened up.


my 2 cents

r404a

[boat racer]

No trouble with the regulator, the problem is with the valve that closes off the oil sump vent to the compressor for 90 seconds on start up.

I think I have a pic I'll post later.

[boat racer]

Its the guy with the arrows pointing at him

[Healey Nut]

There is a kit available to fix that style of regulator .
Im curious about the oil sump vent line solenoid valve is it normally open or closed . That valve doesnt look like the OEM Trane valve which is a normally open valve and should be 1"1/8 line size its a special valve OEM to Trane and has to be installed correctly flow arrow pointing to the suction elbow or you will have oil loss issues .

[boat racer]

It is normally open; energized to close ... I believe it is 1 1/8". The cast arrow on the valve does point to the suction elbow. The piping doesn't look OEM either ... there are sweat couplings on both sides of it and the piping is not very straight or neat.

I checked the action of the timer and the solenoid, they are consistently good, but the action of the valve is not.

[jayguy]

It is normally open; energized to close ... I believe it is 1 1/8". The cast arrow on the valve does point to the suction elbow. The piping doesn't look OEM either ... there are sweat couplings on both sides of it and the piping is not very straight or neat.

I checked the action of the timer and the solenoid, they are consistently good, but the action of the valve is not.

you need the solenoid from trane...hate to say it...but got to say it.

most 'large diameter' solenoid valves need 2 psid (pounds per square inch DROP) to open and stay open (sometimes more). you would not get that in normal situations on this chiller. this would explain your 'erratic operation'.

[boat racer]

I was wondering about that ... aren't almost all solenoids pilot operated ... and in this application pilot operated would not work.

The paint and dirt shows that this machine has been this way for some time ... it at least used to work with this valve.


I'm still dreading replacing it.

[boat racer]

Here's a pic of the crap I cleaned out of the eductor

[Doesn'tPhaseMe]

you need the solenoid from trane...hate to say it...but got to say it.

most 'large diameter' solenoid valves need 2 psid (pounds per square inch DROP) to open and stay open (sometimes more). you would not get that in normal situations on this chiller. this would explain your 'erratic operation'.

Yep, you need the OEM valve and that ain't it. It has something to do with the internal porting and the pilot valve, but I forget what exactly is special about it. This will effect the proper venting of the sump and it's pressure. This could cause erratic operation and also prevent proper oil return to the sump.

Throw a guage on the oil sump and watch the pressure. I found them running slightly higher than the evap press by a few inches hg. If you sump press is erratic so will be your oil press and thats pointing to that solenoid. If sump press is steady and oil press erratic then I would look at the regulator.

[boat racer]

I already decided that the valve had to be a problem ... even when it is energized the pipe gets hot the whole length from the sump to the compressor. My oil pressure is now steady ... if it gets past the first 20 or 30 seconds and the unit actually runs.

Something I did not test last week ... the time delay does not drop out ... it keeps the valve energized all the time ... doesn't matter where the time is set, its just a relay, not a time delay relay. I guess it still could be a problem with the regulator, but these other things are definitely bad and need to be fixed.

So, my goal for tomorrow is to replace the valve and time delay relay.

With the tower on auto and the eductor cleaned up, my oil returned to the sump. Its at the top of the top sight glass, so when I have time, I'll take some back out.

I really appreciate the help I have gotten on this unit.

[M100 Tech]

It was not us, it was our supplier! I will only use a Filter 1592 by the way!

[acjourneyman]

You are going to pull the gas to change the valve right, may as well rebuild the oil pressure reg while the gas is out also, and change the oil.