chiller problems

[iceman6869]

this is a on going problem sense it was new.
It is a advantage chiller M# C-30APTSB , it has a copeland 30 ton 6 cylinder r-22 compressor M#6RP2-350-tsk-800. 460/3 phaze
It keeps taking out the compressors. its seen 9 compressors sense 1989 , every thing from valves to shorted windings. this will be the 3rd compressor that i will be installing , first one had bad valves. looked like it had been liquid slugged . so i installed a suction line accumlator & new compressor, filter dryers, charged system with liquid on the outlet side of the chiller barrel. did not here on noise from the copmpressor at all. checked super heat 14*F , checker unloader ok , checked all the saftys oil, low pressure, high pressure & so on. I'm thinken dam I'm good :D.
two months later it go,s out again pie in the face :mad:. but this time its shorted winding L3. I'm thinking brownout nope phaze protection on it i call the local wholesale house where i got the compressor tell them whats going on. they call me back & thought paper trail that this chiller has gone thought to many compressors no warranty? i tell them about valves on the first one & windings on this one, 2 different problems right wrong don't matter 2 strikes your out:eek:! 5700.00 down the crapper.
funny thing is the unit right next to it is its sister unit . only one number off on the S# from other chiller still has the same compressor it came with, besides the normal pressure control replacement , motors....... its a twin even down to the duct work & mod motors. cant figure it out, need help before i go postal !!!!!!!!!!!
p.s thinking on putting in a two 15 ton twin scroll compressor system. i know what your thinking junk the peace of _ _ _ _. but they wont do that, i tried

[nike123]

How about to try to install some data logging devices for voltage and amperage directly to compressor terminals!
I hawed few times similar situation and when owner upgraded power supply compressors stopped failing.

[Tesla]

Hi Iceman
With this sort of problem the use of data loggers are very helpfull. It sounds like mechanical strain/electrical strain. I would log the superheat, current, voltage, and H2o return temp of both circuits. Is there a pump out cycle on startup? And is there any differance in control of both circuits. The loggers should be left on for one year for quality data and confirmation once the fault is diagnosed and rectified.

[jason09]

an oil analysis would nt go astray.....just be safe.

[old gas bottle]

for a start if its that bad i would agree with the customer that in light of its history that no warrenty can be given on work carried out,take the burden of yourself and put it on them,eventuly they will go for a new one or pass the job onto some other poor unexpecting engineer.:rolleyes:

[powell]

iceman,

I think you have a serious flooding/slugging problem during the run cycle. Busted valves are obvious and a shorted motor can also be the result of a flooding condition. One important rule to remember is that a mechanical problems can cause an electrical failure.

A common example is during floodback the crankcase fills with liquid refrigerant which is heavier than oil. The oil pump pickup tube picks up a oil/liquid refrigerant mixture. As this mixture is pumped through the crankshaft it lubricates somewhat but eventually boils off. The last bearing, which supports the rotor, wears out. The rotor then drops and drags on the stator............shorted windings.

The 6RP2 is a refrigerant cooled compressor and hard to slug during the run cycle.........but not impossible.

I would start with a hard look at the TEV and other controls.

Also, adding a suction accumulator is good but, sometimes it's just a bandaid which cannot cure the problem.

Good luck

[Gary]

Also check the running voltage on all three legs. It is not unusual for a malfunctioning compressor to burn the contacts in the starter, providing low voltage to one or more of the windings. Burnt contacts can take out the replacement compressor.

And make sure the crankcase heater is working, too. You could be having migration problems.

[GreenFly]

a good data logger is called a Clima checker. You get a din rail mount or a service version.

[chilled kiwi]

Check the oil return system as well, for either excess or starvation of oil.
A suction drier is also needed to clean up any acids or waxes in the system.
What is the load range. If the load can drop off the TX valves may have troble maintaining superheat.