My a/c comes on fine; however, if the fan is on low it kicks the circuit breaker after a couple minutes. It works fine on high.

Bad fan motor. Multi-speed motors have a set of windings for each speed. Your high speed is bad so the only solution is to replace the complete motor. When motors are going bad they will over heat and kick out on the heat safety. As it cools back down it will start again for a short time again until it gets hot again.

just replace the fan ..... its seems there is some voltage problem

Check for fan operation by turning the fan control at the thermostat to "on". If the fan blows, it works. If not, check a circuit breaker or fuse.

If the fan blows when forcing it on with the thermostat but not in automatic, check the fan control circuit in the air handler. Danger: high voltage, beware! There should be a system wiring diagram inside the air handler somewhere.

Check incoming voltage circuit and wiring for proper gauge wire etc, and have compressor start capacitor tested, or replaced. I'm curious as to why circuit breaker didn't trip in panel when compressor causing so much current draw, that's reason for checking wiring etc to AC circuit.

Hi,
No this sounds like a bad compressor....a bad capacitor would just be hard starting, not kicking the breaker after running..

heatman101

Whether its a central air unit or a wall unit, make sure the condensor is clean and air can flow thru it
make sure the condensor fan is running, the condensor fan keeps the compressor from over heating
if the condensor fan stops running the compressor will over heat and trip the circuit breaker. good luck!

If all is the same as when it ran good, such as same power cord (no extension, or properly sized extension ) same generator output voltage etc, then I'd check amp draw when compressor kicks in. Good chance compressor start capacitor may be faulty.

You need to verify if the problem is the unit or the breaker.  To do this, you will need to measure the current it is pulling from the power source.
If the unit is pulling too much current, then the unit is the problem.  If the unit is pulling as much or less than its rated current draw, then the circuit breaker is worn out.
The units WILL pull more power when hot outside.  It should not trip a breaker unless something is wrong with either the unit or the breaker.
A current draw test will tell you for sure.
If it's not the breaker, then it's probably low refigerant causing the issue.

Bad fan motor