compressor died! Why?

[bowhunter86]

So yesterday i ran a no cooling call. 5ton trane heat pump for a training room. Low pressures, 40deg superheat, no subcooling, flahsing sight glass, and going off on freeze stat. I charged the unit to 10deg superheat as specified by trane per the space and ambient conditions. Today no cooling. Go back out and compressor is dead. Pulling 91amps then tripping the internal. I weighed out the charge and i was dead nuts on the charge per the installers notes. I personally am ok with it but the account manager wants a detailed explanation as to why this compressor died. I dont beleive i did anything wrong but Im not perfect. Any one have an idea?

[bowhunter86]

Oops. This doesnt belong here.

[BaldLoonie]

OK, moved to tech to tech.

Anyway, I'd guess comp was damaged from running hot with the 40° superheat. Them running it low on charge probably did it in.

[bowhunter86]

Kinda what i thought. A system running that low on charge and then actually getting loaded up and doing work could cause a failure. You just sorta feel bad when stuff like that happens.

[Six]

You slugged the hell out of it when you recharged it....j/k.

Having to defend my service practices to an accouns manager would piss me off to no end. I once lost a compressor after a quarterly and got the 4rth degree from that companies facilities manager. He wanted to know why I didnt catch it.

I told him s**t happens.

Sometimes there is no rhyme or reason. You do your best and dont apologize

[dlove]

You slugged the hell out of it when you recharged it....j/k.

Having to defend my service practices to an accouns manager would piss me off to no end. I once lost a compressor after a quarterly and got the 4rth degree from that companies facilities manager. He wanted to know why I didnt catch it.

I told him s**t happens.

Sometimes there is no rhyme or reason. You do your best and dont apologize

True so true. I came up on a unit in real bad shape, no PM in years. cleaned it up, checked it out, left it running as designed. Dropped dead two days later..

don't give an 80 yr old man a 20 yr old tune up sometime they can't handle it

[dandyme]

just tell the jack@@@; you were not there when it took a dump

[jrgreene1968]

just tell the jack@@@; you were not there when it took a dump

this would be my reply

[VTP99]

[QUOTE=bowhunter86;13345131] I personally am ok with it but the account manager wants a detailed explanation as to why this compressor died.

If you change it out, throw it on his desk and tell him to tear it down for his answer.

[allan38]

Running a system low on refrigerant overheats and stresses the compressor. It''s a gamble, it could last for years, it sometimes fails quickly.

I can cut the compressor apart and do a detailed autopsy. It will cost you an additional $$$.

[HvAckid82]

can you reverse the roation and break it loose? Scroll compressor? Did you hit it with a hamer, you would be surprised that sometimes works. Hard start kit?

The account manager is just doing his job, hes not accussing you, is he? He has to give an answer to the customer

[2sac]

Depending on how long it was working improperly, it got used to that. Now all of a sudden it has to do work and it doesn't like doing work. How many times have we seen this with condenser motors? The day after you clean a plugged coil the motor takes a crap.

[monkeyspanners]

A guy i worked with was servicing a unit on a milk cooler, while pumping it down to change the drier the compressor died... Luckily the customer could see that it was just a coincidence.

Years later on another farm i replaced three small milk tanks with a 15,000L one, left a smaller tank running in the room next door, while i was back there the next day finishing off i heard the old compressor start to labour then a hum and silence! Not a day too soon!

I have offered to have compressors sent away for a failure report (compressor rebuilder here do them) but once the customer realised they would have to pay for this service they soon changed their mind. I expect though you would have to be careful or you could end up with a customer wanting you to provide a report for free proving you didn't kill it.

Everything that has been made will fail and turn back to dust in, its just a mater of time.

[bowhunter86]

Before i put power back to it after the internal closed i hit it with a hammer a few times. Once it came on there was no doubt she was shot. It sounded all broken apart inside. And no i dont think hes doubting me hes just looking for an explanation for the customer. But the way i see it thats his problem. He sits in the air conditioning all day and talks on the phone. I work in the heat all day and fix people like hims' air conditioning. I figure thats his job and it doesnt concern me.

[AcDOCnTRAINING]

So yesterday i ran a no cooling call. 5ton trane heat pump for a training room. Low pressures, 40deg superheat, no subcooling, flahsing sight glass, and going off on freeze stat. I charged the unit to 10deg superheat as specified by trane per the space and ambient conditions. Today no cooling. Go back out and compressor is dead. Pulling 91amps then tripping the internal. I weighed out the charge and i was dead nuts on the charge per the installers notes. I personally am ok with it but the account manager wants a detailed explanation as to why this compressor died. I dont beleive i did anything wrong but Im not perfect. Any one have an idea?

Number of things; (this has happend to me before)
Oil and refrigerant mix in the system, low refrigerant pressure = low oil pressure. The motor also ran without a load which causes it to overheat.
It could of had damaged windings by the time you got there. I always OHM windings and test caps when refrigerant loss happens to insure me that the motor is not failing, but to be honest there are no clear signs of a upcoming lock up

[hvac17011]

I will have to throw a hammer in my veto!!!!!!!!lol

[bowhunter86]

Well hvac17011. I dont think you should be hitting those digital scrolls with a hammer. Thats something us working men do to try and get a customer some ac. It never works but its worth a try. Just stick with your digi cools and fancy screw drivers. Im always here to do your repair work on a saturday if you need me!!!!!!!!!!!!!!!!! haha

[Six]

Well hvac17011. I dont think you should be hitting those digital scrolls with a hammer. Thats something us working men do to try and get a customer some ac. It never works but its worth a try. Just stick with your digi cools and fancy screw drivers. Im always here to do your repair work on a saturday if you need me!!!!!!!!!!!!!!!!! haha

We use to hit Dunham Bush Medium Screw Compressors with a 2 pound sledge hammer.

Oil float would stick.