Can the internal temperature switch be changed on Trane CRHK200 compressor?

[H20ENG]

This is a 20 ton compressor on a Trane SFHC AHU. Its the first stage compressor with unloader. It was blowing the control fuse, and I traced the problem to the internal temp switch (schematic shows 2 internal switches). 15 Ohms to ground.

It looks like the plate where all the terminals are located can be unbolted from the compressor. I am wondering if this is just a Klixon on the back of the plate, or if its somehow wound into the motor.

I'm hoping to change this small part rather than the whole compressor.

I'm hoping some of you out there have dealt with this before.
Thanks for any info!

[BillDuffy]

It's more than likely wound into the winding, klixons are surface mount in the terminal Box sensing the shell temperature.

[H20ENG]

I was thinking they may be wound in thermistors, but the schematic shows 2 temp switches. I was hoping these were just Kilxons on the back of the plate that can be changed out.

[H20ENG]

Wish I could find a cutaway or more info. Thanks for the reply.

[Juan Madera]

You might try pumping the compressor down and pulling the plate just enough to see if the internal wires are compromised. If it is re-insulating a wire, might be a save. If the switch or thermistor is grounded out in the winding it is a replacement job if you want thermal protection. With switches, you could jump them and run the compressor til it dies should your customer wish this. If it is a thermistor with a control that has some rudimentary smarts that looks for a change in resistance, then it is a change out for sure.

[maxster]

that one of those big CAN copressors trane put in the rooftop series when thefirst came out.the unloaders are the only thing that can be unbolted off the terminal plate.take them out of the circuit or change the compressor

[H20ENG]

This is what I was wondering. Is the klixon mounted to the plate, or to the windings? In other words, if I replace the plate, is the klixon mounted to it, or is the terminal on the plate just for the wires to the internal klixon?

Thanks for your time,
Chris

[Six]

Had one do that in a Carlyse O6D. Isolated it and told the compressor we would let it go until it died.

[JoshMc]

Can't change them.

[maxster]

i remember the cover itself had dozen 3/8 screws to view the compressor power wires terminals,unloaders and i swear a HP control and a terminals for an internal thermistor.i was with TRANE service at the time and i think the factory said install a banded temp control to knock the compressor off on over temp,but where to mount it is a mystery 20 yrs later...sorry tell you one thing when those copressor short out it is border line NUKE freon and all items related

[zw17]

Had one do that in a Carlyse O6D. Isolated it and told the compressor we would let it go until it died.

Are you the 'compressor wisperer'?

Do you see dead compressors?

[maxster]

when TRANE came out with the scrolls in the self contianed they had a discharge temp senser on the top of the compressor.it caused more problems with random trips so they had us cut them out of the circuit...i would cut it out and just run the compressor..if it takes a dump by the time the heat would of built up to trip it the compressor will be cooked.

[allstar08]

You might try pumping the compressor down and pulling the plate just enough to see if the internal wires are compromised. If it is re-insulating a wire, might be a save. If the switch or thermistor is grounded out in the winding it is a replacement job if you want thermal protection. With switches, you could jump them and run the compressor til it dies should your customer wish this. If it is a thermistor with a control that has some rudimentary smarts that looks for a change in resistance, then it is a change out for sure.

you can put in a resistor with a value that the control will not alarm on. so the compressor is always the right temp if you know what i mean. Until the compressor goes boom. I have had them last for years, and some are still running.

[gwoner]

I agree just install a resistor so the unit thinks the temp is correct so not to trip .

[hvac69]

That compressor does not use a sensor, it is just a contact, open or closed. I have done the sensor trick on Copelands though. Can not be replaced.