If my home AC unit runs out of freon and keeps running, will it damage the compressor or breaker?

I would also say yes, as the oil that lubricates the compressor travels freely with the refrigerant throughout the system, so any leak will also be causing it to lose precious lubrication oil and cause a compressor burn out eventually as the previous responder mentioned. It is normally a closed system and engineered to allow *some* oil to travel into the system and return back to the compressor with no dammage, but once opened (leaking refrigerant) that oil will escape with the refrigerant. If caught reasonably quickly, again, it won't have caused any dammage, and the leak can be repaired, a filter-dryer {http://www.rparts.com/Catalog/Major_Components/fil... installed, and the proper amount of refrigerant added. Back to normal. {grin} Allowed to leak for an extended period though, such as the case with yours, it may indeed be what caused the compressor fialure.

Al

A hard start will sometimes fix it or keep it going a few more years so it was worth a shot to put it on. The sad thing is you probably need to replace the compressor. I would check into the warranty and I would pay to replace the compressor rather than go with a new unit. It makes more sense to replace the compressor than to change units these days. If you do bite the bullet,get a heat pump. The newest heat pumps will pay for themselves in energy savings.

First I would get someone else to look at it. The reason being is the service company knows that it is a closed system and you will not lose freon to the degree you have with out a leak. My unit has ran for 15 years and I have never added freon. If they overcharged it with freon they could be your problem. I would find a dealer that sells your type unit and have them cover it under warranty and do the change out. You will probably have to cover the labor. Make sure anytime you have someone check your unit that they give you the super heat and sub cooling numbers they found out when they calculated how much freon to add before they do anything. If they can't do this ask them to leave. Sorry for the black eye on the profession, Hope this helps.

the compressor is broken from overheating from lack of freon while running for a long time.some units have a low/high pressure cut off module

Usually that is not possible. The system should have a low pressure cut out switch. When the refrigerant gets too low it cuts out the compressor preventing it from self destructing.

how much does a compressor cost for a 5 ton trane unit home ac

Low/no refrigerant could definitely damage the compressor. It is unlikely to have damaged the compressor's motor and should have no affect on the electrical supply (breaker etc.) whatsoever.

It is not related directly, but better you must fix it out soon!

yes....it can burn it out.