cutting off GE AZ38H12DADM1

[brad]

Have these GE PTAC units in the building.They work fine except one of them keeps cutting off.It will start and run fine for about a couple hours or so and them just shut off.If you wait about 20 to25 minuets you can restart it and it will run for awhile and then shut off.None of the other units do this .They are all the same model.What do you guys think? They are not on remote thermostats just unit operational.

[JWWebster]

Might be the compressor overload, Have you checked that? If you have a bunch of them units you might want to keep some of them on hand.

[brad]

I'll check the overload,thanks for your time and help.

[brad]

Checked the overload and it is ok.The back coils are clean and the compressor wasn't realy hot.What else could be cutting it off.As I said the unit cools good untill it stops.There are some sensing unit on the front of the evap coil.These are for cycling the unit are the not?We do have one exra unit,but we still need to get this one up and operating.

[jumptrout51]

You may have a faulty thermistor on the front coil.

[brad]

That's what I'm leaning toward.How would you tell?

[jumptrout51]

Pull one off a unit that is working and test it on the unit with a problem.
You might try pulling the thermistor out of the coil and let it hang away from the coil and run the unit.
That way it should not sense at all.

[brad]

Ok I'll try that.Thanks for your time and help

[brad]

Changed out the thermistor on the front and it seems to be working better now,at least it hasn't gone off.