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Originally Posted by ECtofix

Just info.

Had a True T23F tripping a breaker. Isolated down to the condenser. Ohmed comp windings as good. No issues there. Megger tests to compressor case was good too.

With condenser practically in my lap, using an extension cord and an in-line GFCI as aux power source, I'd plug in condenser. The compressor would do an abbreviated startup kick along with the sound of something from the compressor's vicinity akin to the nearly imperceptible noise of dropping a tennis ball on carpet from say...a foot high.

I ordered and replaced the start components. SAME RESULT!

Retested compressor. Same readings. Compressor WASN'T testing as shorted.

Disconnected compressor terminals. Applied power. Carefully touched line input to C terminal. Tennisball noise and GFCI tripped.

Now I have no faith in my megger.

If you do not have a hermetic annalyser, get one, if it will not start with a "annie" then no matter what the noise, its toast.

Also, they allow you to bump the compressor backwards, I still replace it if it starts after this, but it will get them out of trouble on evenings, weekends or while the correct compressor is ordered.

Jim

Originally Posted by tipsrfine

I'm starting to think something is going on here that the op has mis-stated, mis-wired, or overlooked. The only way I'm seeing this make sense is that the "common" he mentions is actually hot AND the compressor is shorted to ground.

3. Took that disconnected wire that goes to C terminal and touched it to compressor's intended terminal. What does this even mean?

Yeah, I'm with you on this. I've been biting my tongue, waiting for someone smarter than me to help sort it out.

Originally Posted by VTP99

Hot common to ground short. Is my guess.
His post # 8 3&4

I'm starting to think something is going on here that the op has mis-stated, mis-wired, or overlooked. The only way I'm seeing this make sense is that the "common" he mentions is actually hot AND the compressor is shorted to ground.

3. Took that disconnected wire that goes to C terminal and touched it to compressor's intended terminal. What does this even mean?

Hot common to ground short. Is my guess.
His post # 8 3&4

Originally Posted by tipsrfine

I guess I'm missing something here, but I've read through the thread & can't find it. How does it figure that a compressor is bad when it is a 115 v & only touching the common wire to the common terminal on the compressor trips the breaker WITHOUT any wires going to the run & start terminals on the compressor? Pardon the brain fart if this is what is happening to me.

Good question....my original thought was that the compressor is locked up. Second would be grounded winding . Either way the compressor is down. I personally have never have a locked up compressor last for more than 3 months after bumping.

Originally Posted by ECtofix

I've always heard the hum of a locked compressor, then the click of the overload doing it's job in those situations.
In this case, during my testing, RUN and START terminals are NOT connected. Merely having COMMON connected trips the breaker.


I'm with you 100% and appreciate the feedback and reinforcement. Had it not been for the maker of this unit I brought up (True Manufacturing) doing a roving training seminar, your point would've been new to me. ANY info you offer is appreciated.
Speaking of TRUE, they are adamant about checking for and suspecting line drop. What leaves the service panel at 120v can easily translate to only 100v applied under load after delivery through hundreds of feet of inadequate building wiring. Dollar General stores are the worst.
Regarding extension cords, I'll give a restaurant manager MORE than he/she wants to hear if I find an extension cord feeding their equipment. I usually get their attention explaining in $$$$s to replace what was once a perfectly good compressor destroyed with an extension cord.

I guess I'm missing something here, but I've read through the thread & can't find it. How does it figure that a compressor is bad when it is a 115 v & only touching the common wire to the common terminal on the compressor trips the breaker WITHOUT any wires going to the run & start terminals on the compressor? Pardon the brain fart if this is what is happening to me.

Originally Posted by Airmechanical

it does sound like a locked rotor which will cause overamping and tripped breakers

your megohmeter to the compressor case is an invalid test unless you removed a spot of paint off of the compressor

testing tools are only as good as the people using them

learn the difference between an electrically bad compressor, and a mechanically bad compressor



.

He has stated he will not attempt to bump it. Nothing more to do but change it.

*

it does sound like a locked rotor which will cause overamping and tripped breakers

your megohmeter to the compressor case is an invalid test unless you removed a spot of paint off of the compressor

testing tools are only as good as the people using them

learn the difference between an electrically bad compressor, and a mechanically bad compressor



.

Sounds like you have done evrything you could to figure this dilemma out. The conlclusion is that the compressor is tripping...why? who knows at this point .change it out. I would be almost tempted to cut it open and take a look if I had the time and it was not warrantied.

Originally Posted by VTP99

EC,
Are you saying it starts then trips or trips instantly ? A locked rotor will trip the breaker this you know. I will try that trick but the opportunity is at hand for you now.

I've always heard the hum of a locked compressor, then the click of the overload doing it's job in those situations.
In this case, during my testing, RUN and START terminals are NOT connected. Merely having COMMON connected trips the breaker.

Originally Posted by skpkey9

ECtofix The extension cord thing was just an example to get you to understand why it could void a warranty thats all I was saying with that. its perfectly fine to do what you did everyone does it, but do you see where im coming from...

I'm with you 100% and appreciate the feedback and reinforcement. Had it not been for the maker of this unit I brought up (True Manufacturing) doing a roving training seminar, your point would've been new to me. ANY info you offer is appreciated.
Speaking of TRUE, they are adamant about checking for and suspecting line drop. What leaves the service panel at 120v can easily translate to only 100v applied under load after delivery through hundreds of feet of inadequate building wiring. Dollar General stores are the worst.
Regarding extension cords, I'll give a restaurant manager MORE than he/she wants to hear if I find an extension cord feeding their equipment. I usually get their attention explaining in $$$$s to replace what was once a perfectly good compressor destroyed with an extension cord.

Heh Heh

Originally Posted by skpkey9

ECtofix The extension cord thing was just an example to get you to understand why it could void a warranty thats all I was saying with that. its perfectly fine to do what you did everyone does it, but do you see where im coming from...

Skpkey,
This is a good point. Lets hope some owners are listening with open ears. How many times have we seen 100 foot extension cords used to bridge a two foot gap between the equipment cord and the outlet ?

ECtofix The extension cord thing was just an example to get you to understand why it could void a warranty thats all I was saying with that. its perfectly fine to do what you did everyone does it, but do you see where im coming from...

EC,
Are you saying it starts then trips or trips instantly ? A locked rotor will trip the breaker this you know. I will try that trick but the opportunity is at hand for you now.

Originally Posted by skpkey9

ECtofix : well its kind of like this...
say you have a customer that you just changed a compressor on their system and you found out the reason was that they used an extension cord ( undersized wire ) and loss of compressor was do to voltage drop... now you explained tp them why they could not use an extension cord...couple of days pass and they call back saying unit isn't cooling, you arrive to find the same extension cord hooked up and they want it changed under warranty.... same with manufactures they say dedicated circuit with no GFI....and I have been asked before.

Man, if I'm looking for any possible solutions to a problem, this is the right place. That's why I come here.

HOWEVER, it was MY extension cord. I was merely circumventing the inaccessibility the condenser's dedicated outlet built into the freezer. I'd already isolated the problem to the condenser, I was merely replacing thermostat's function by BEING the thermostat with my extension cord - for testing purposes only. Same thing applies regarding MY GFCI doohicky - which rests once again inside my toolbox.

Originally Posted by VTP99

Try the reverse trick. What do you have to lose ?

Compressor isn't locked up. It trips the breaker. Besides, I thought YOU were going to be the one to try that.

Originally Posted by VTP99

Skpkey,
There's another thread going about reversing single phase. Basically reversing the start and run windings.

Actually, I'm the one who said that and ultimately hijacked that thread.

SIDE NOTE: Logging in here on this forum makes me remember the days when my company's techs "reported in" each morning by gathering at the warehouse's picnic table. The discussions there were always educational, often funny and sometimes turned into a debate fed by a bunch of brainiac technicians. We got so much from those gatherings that we'd show up for work 30-45 minutes EARLY. Our launch time was 7:45; then we'd all jump into our vans to go off our separate ways to be someone's hero.
One of the guys summed it up by saying he learned more in those minutes of our morning gatherings than he EVER could through the rest of his day.

Now we all set off for our first calls from our homes. It's a rare treat to find two or more of us at the shop simultaneously.

Go to ( Bad Compressor ) last post was at 7:00 PM today.

That will not do any good on a compressor (single phase)...I havent seen that thread but you could do more damage then good when you bring capacitors in the mix...

Originally Posted by skpkey9

and when I say use a larger start cap its to bump a locked compressor then go back to proper sized one...

Skpkey,
There's another thread going about reversing single phase. Basically reversing the start and run windings.

and when I say use a larger start cap its to bump a locked compressor then go back to proper sized one...

rev only works on 3 phase....single phase use larger start cap.

This compressor is toast just replace compressor have GFI changed and off to the next nightmare you go...