CVHF910 losing oil

[djones]

Just rebuilt a CVHF910 Trane and the sump keeps running out of oil. Went over clearances recorded several times and all are ok?? AT 83% here are the specs. Chill water was 42.3 & 51, cond. water was 81 & 87, Cond. ref. temp was 88 and cond. pres. was 1.2, Ev. ref. temp was 40.5 & Ev. ref. pres. was -8.5, oil diff. pres was 19.8 and oil temp. was 132.8, also ev. approach was 1.8 Any ideas??

[Nuclrchiller]

How certain are you that the internal oil line, that is in the discharge volute, is properly reinstalled? Does the chiller have the older style oil sump, with a vent line? If so, have you verified the normally open solenoid valve on it is operating properly?

[djones]

Yes sir, i checked the oil line. And it is the old style sump with the vent line. I checked it for proper operation and it is ok also.

[Nuclrchiller]

On the vent line solenoid, did you check both electrical and mechanical operation? I have seen that valve operate electrically correct - that is, the coil energized and the sound of the valve stroking, but the valve not actually opening due to debris blocking an internal passage. Oil loss to the point of shutdown occurred in about 30 minutes of startup.

[triggerhappy]

What is the pressure in the oil sump.
You can take the reading at the oil drain valve.

[Nuclrchiller]

What is the pressure in the oil sump.
You can take the reading at the oil drain valve.

True. But this chiller should have a UCP2, or later, panel on it. The oil sump pressure transducer will let you read that pressure at the control panel. If you have doubts about the reliability of it, Trigger's suggestion is a good way to verify it. You can also verify accuracy of the pressure transducers by comparing the readings of all of them while the chiller is off. They should all read the same then.

[triggerhappy]

Need to know the sump pres. in relation to the evap. pres. however you arrive at it.

If you use a gauge you will rule out conversion and transducer problems.

You would have to have quite an internal problem to be loosing alot of oil.

As for the sleeve brg. supply line that is soldered in if it leaks it is still contained by the seals.

If you have a vent line and solenoid you should see the oil hold up in the ball brg. cap and they go down when the solenoid opens.

You should be able to see the oil flows in the sight glasses.

Of course you could alway use the old method and measure the oil flows like we used to when we rebuild double enders and sidewinders. Early CVHE rebuild manuals call for this to be done.

[djones]

OK. Must be the vent line not opening up because i have -8 ev. pres. and only -3.5 sump pres. And i did only check electrical operation of solenoid. Will have to pressurize and take valve apart i guess. Also, thats right on the time. Only runs about 30 minutes until shutdown.

[djones]

EV. pres. was -8 and sump pres. was-3.8 Checked vent valve electrical but have not took valve apart yet.

[Nuclrchiller]

Taking all the removable parts out of the existing valve and replacing them with parts from a new valve would allow you to make repair with chiller heated to 0 psig, if your customer needs quick repair, and he's ok with that. It's what we did.

[djones]

My posts have not been showing up for some reason. Anyway, ev. pres. was -8 and sump pres. was -3.8 Checked vent valve electric but have not took valve apary yet.

[djones]

Thank you, im gonna heat it up in the morning and try repairing valve before going any farther. Will post update if it works.

[Nuclrchiller]

Good luck. Sounds like you're on top of it.

[Healey Nut]

Is the vent line solenoid valve the Trane OEM valve and which way does the flow arrow point on it .. To the suction cover or to the oil sump ??

[RichardL]

Wow.....30 minutes and you lose the entire oil charge. You posted that the compressor was just rebuilt. On that I must ask if the bearing cap and gasket was replaced behind the Ball bearings. Thats the one with the six long threaded studs that go the the rear bearing web. The clearance on that bearing cap to the rotor shaft is extremely close and is often overlooked.
I did a CVHE1250 and screwed up not replacing it. Strangely it also took 25-30 min to dump all 7 gallons...

[djones]

Arrow points to suction cover and it is oem. Also, i only replaced the gasket. May have been a mistake. It wont lose all 7 gls. in 30 minutes but you can clearly see oil level dropping pretty fast, so i just shut down. But, in the return line sight glass for the thrust bearings you can see a good return to the sump.

[djones]

Update: Problem solved. It was the vent line valve not working. Sounded good but nothing going on inside. Pressurized machine and replaced valve and its running great. Thanks for the tip nuclrchiller

[Nuclrchiller]

Update: Problem solved. It was the vent line valve not working. Sounded good but nothing going on inside. Pressurized machine and replaced valve and its running great. Thanks for the tip nuclrchiller

You're welcome, glad it helped.

[milkyway]

nice