Adding oil to trane compressor help

[dan_4818]

Hey guys

I've been working on a 600kw portable trane chiller. Just want some advice on how to top up the oil in one of the compressors. The Fridgy before me put in 12litres of oil then proceeded to add gas into it. Now the compressor won't start as its got a low oil level fault. Now I still need to add around 35kgs of refrigerant but I can't get te compressor to start cause of this oil fault. What's the best way to add oil without evacuating the refrigerant out of compressor. It was a port near the oil filter for filling

Cheers daniel

[FreezerGeezer]

What chiller is it?
Do you have an oil pump?
Why do you need to run the compressor to add refrigerant to the chiller? Or is it that you are concerned that it won't run after you've added the other 35Kg?

[dan_4818]

Don't have the model number on me. No oil pump. Just a gauge line and a container of oil to draw from. I can't get anymore added into the liquid line and don't want to flood te compressor and wreck the valves

[mikeref]

With 12 litres already added, sounds to me you don't want more oil. What does the oil glass show?
Could be a buggered oil separator or the oil pressure switch/ transducer if cactus.
Townsville eh? Which company are you with? Did a couple of years there.

[dan_4818]

I'm with c&m solutions. Only a new company. My back ground is all install. Done bugger all breakdown so trying to teach myself basically. It's a two compressor system. System 1 has had 16l of oil added but for some reason the other Fridgy only added 12 litres to system 2. I'm thinking about heating up the sump to try get the oil pressure up so the unit will start then I can just chuck some in through the gauge line

What's the best way to charge it. There's a port on liquid line but I can't get any more added as its a higher pressure then the bottle. Not sure if I can vapour charge into the auction line at the compressor

[mikeref]

Ah, Daniel. To be honest, working on a 600 kW chiller is really something that you don't want to be over confident with. I'm guessing you are on call tonight and the pressure is on you...however....you are going to need some on site help.
There is no charging of oil via the liquid line port, only done on the low pressure side of the system.
Call your supervisor and have an experienced breakdown mechanic to help you out. The company you work for should understand when asking for help. That is WAY BETTER than working alone on this problem and wasting the customers time with bugger-all result. (Telling you how it is cause i've been in your situation )

[FreezerGeezer]

Agreed. You need more knowledge & more tools - specifically, an oil pump.
Get onto one of your senior tech's or supervisor & get their assistance - they may grumble, but they'd rather that, than the LARGE cost of repairing that chiller if you accidentally break it.

[dan_4818]

I wasnt talking about charging oil through liquid line. I was talking about charging more refrigerant through liquid line. There's a port for charging oil on the low side either side of the oil filter and that's where I'll be charging it. There's no oil pump available so I guess I'll just be bridging the low cut out control to get the compressor running

[FreezerGeezer]

Sorry, you've lost me here.
Is it a recip, screw or scroll compressor?
Are you planning on pulling a vacuum with the compressor in order to draw the oil in? As far as I can remember, only centrifugal Tranes will be at less than atmospheric on the suction side in normal operation.
I do recall that scrolls are not to be run in a vacuum for any reason. And I think the same applies to screws.

[dan_4818]

It's a heli rotor compressor. I checked oil level in the oil separator and according to the manual I found on the net the oil level is about right. In going to leave the sump heaters on and hopefully that will add some heat to it and get the pressure up so it will start so I can pump more gas in. It's going in at the moment but very slowly. And I have 30kgs to go. It will get there.

And for clarification. I was going to shut off suction and discharge valves. Recover refrigerant. Then use a vac pump to put compressor in vacuum and draw oil in that way. But looks like its got plenty of oil just needs pressure to be up

[Tesla]

Hi dan it could just be short of gas and the oil could be logged in the evap. You should check oil levels after adding gas and running at full load for about 4 hours as there may be too much oil.

[dan_4818]

ok. More info on the chiller. Its a RTAA-217 Chiller. 10 condenser fans, 2 compressors on two circuits.

Done some more work on it today. Got the refrigerant all added. Left the sump heaters on all day and fired her up. Ran for about a minute then shut down. Low oil flow fault again. Done some research and found out this is quite a common fault. Went through some checks. Oil filters are brand new, oil pressure is good (checked against other working compressor), has a new differential switch (this isnt tripping), oil level is good, getting good pressure passed the solenoid valve in the oil return. And thats where i have stopped. I have to go out of town working for the next couple of weeks so someone else will be looking at it. From what i have researched it could be anything from a faulty oil temp sensor, fans not running correctly, dirty coil and right up to a sticky valve causing the compressor to start loaded.

Unfortunately i ran out of time on it, i would of liked to of found the problem myself but oh well. Apparently 4 fridgys have looked at it and i am the closes to have gotten it running. First one to get compressor circuit b up and running. It has been out of service for 380 days lol. So i dont feel too bad.

Cheers for your help

[sondasons]

Hi Dan 48-18
Let's change suction sensor gas (SEN0951)

[serviceman]

You'll have the complete model of the machine?

[ALFONSOTHAWE]

How long does it run to trip on oil control? RTAA does not have oil sensor. Are your connection to oil differential switch capillary tails or 1/4" if the later leave it if the first replace with the later. Must be R22 chiller with CHHB? compressor. Something to do with foaming in oil system if oil filter is new and oil switch is new. Observe you condenser pressure.

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