Air conditioner runs for several minutes then

indicates problem motor , overheating in the wiring or excessive loads in the drier

DO NOT install a 20 amp breaker, you can cause a fire. The breaker is rated for the WIRES, and unless you change out the wires, the 15 amp wires will overheat and can cause a fire.
Typically, A/C units need dedicated power, with nothing else on that circuit.
One step that you may try is a new 15 amp breaker. Once a breaker starts tripping, is starts tripping earlier....
You may wind up running a new circuit for the A/C, if you do, size it for the A/C.

You have too small a cord on it if it's heating up and then popping your breaker. The a/c has am amp rating on it's data tag, read it and then read the amp capacity of your breaker and the cord your using. If the a/c draws more than 80% of the rated amps for the cord and breaker then you need to find another way to power it up with a bigger cord and a bigger outlet. DO NOT just install a bigger breaker, it is sized for the wiring in your home and a bigger amp draw on that wiring could burn your house down.

It sounds like the unit may be overcharged. Has anybody added refrigerant?

no you need to install a hard start kit on that unit to help it start up easer i can get one for you and help you install it by yourself jason

check the condensor fan in the rooof unit. It's the fan blowing on the cpil on the roof.. If it failed, the head preasures can becme excessive andwork the compressor hard causing the breaker to trip. Let me know and good luck, Ned_

Unit is drawing two may amps for the breaker. Could be compressor sticking.

Possible overcharge or bad breaker. You need to check the amp draw for the unit. If you draw under full load amps and trips breaker breaker is bad.Rus

It is entirely possible that a five minute test would not produce any noticeable amount of water. Turn off everything in the house that is using electricity and your 20 AMP service will be sufficient to run your AC.

If the fan is running and the compressor is getting hot and tripping off you may have a failed capacitor.