Trane RTAD Compressor ceased

[wakefield]

Hi I am new to the site,

We have a TRANE RTAD 165 unit, recently came out of warrenty, then the troubles started, new temp sensors on circuit 1, this stopped the lp cutots and superheat problems we were having running fine now. not so with circut 2. We encountered the same problems with circut 2. temp probes ordered, system pump down was attempted, lp switch fault encounted, system was then pumped down, lp switch ordered, circuit left in pumped down state. while waiting on parts , circut two tried to run, tripping the breakers on over current fault, compressor windings and contactors checked, tested ok, dignostics deemed to be a locked rotor, oil sample to be taken, what was found, no oil in the system, no leaking oil found from system. the real question I have is where would, could have the oil gone in the system to cause the locked rotor situation....

[nike123]

No oil in system, that is very odd!
Do you mean low oil level?
How did you checked that?

[centrecipew]

Hi, You say the compressor ran in a pump down state- did it run into a vacuum?
It is not advisable to run these compressors below 10psi.
If so this could lead to a mechanical failiure.
Also, where did you try to drain oil from?.
At a stopped position the only reliable drain point is at the bottom of the oil separator.
Typically -the fuses should be removed from the circuit and the circuit locked out to prevent accidental start up.
In one instance the compressor was deliberately started reverse direction to try to free the rotors.It worked!! However this will never be endorsed by the manufacturer and could also lead to winding failiure and the additional complications of a burnout cleanup. So proceed with extreme caution. At the very least ,prime the oil circuit prior to start up. ALSO the applied voltage mustbe only for a split second. Good luck.

[wakefield]

No oil in system, that is very odd!
Do you mean low oil level?
How did you checked that?

Hi, Samples were attempted to be taken, we could not get any oil from the bottom of the seperator, nor the oil return line, some how 11 L of oil has disappared, we now believe a faulty oil seperator or a crack in the PHE may be responsable

[El Padre]

Is the chiller oversized, continuos operation of it at part load may have resulted in most of the oil charge ending up in the evaporator.

Cheers

[wakefield]

Is the chiller oversized, continuos operation of it at part load may have resulted in most of the oil charge ending up in the evaporator.

Cheers

Hi, thanks for the answer..

We have had the chiller unit in for two seasons, unit set up for alternitive starts, normal load on chiller is about 66% per circuit. loads are reasonably normal. but how long at a guess would it take to take the oil charge through to the evaporator.

[goshen]

did u find a leak?11 liters is a lot of oil !!
did u check the evaporator?
that is where the oil migrates to sometimes

[wakefield]

Thank you to all who posted, next we are going to finish reclaiming the refrigerant, vac out and fill with dry nitrous to pressure test overnight for leaks, then investigate the evaporator etc..

[serviceman]

verifies the distance sensors longer than if you are very inside marked mistakenly saturated evaporator temperature

[Dacky]

Hi,

One brief question, maybe you could help. I have a company that sells Goodway cleaning equipments, and to one of new customers, the service engineer quit, and the manager doesn't know the I.D. of the heat exchangers tubes in an RTAD 145, to order brushes. By any chance, don't you know?

Thank you.