[Rathji]

Note: I am not an electrician, but have pieced together the following understanding over the years.

Try and find another plug on the same breaker and test the unit there. If the problem is the same on every plug on the breaker ( do NOT use an extension cord) , then test it on another breaker circuit. If the problem continues then the problem is with the A/C unit, and you should either buy a testing device to see what amps it is drawing, or take it in to a service guy.

If the problem is only with half the plugs on the breaker, then there is something wrong with your wiring. An electrical device will draw the electricity it needs, which means if there is a 'choke point' ( badly pinched or frayed wire, wire of seriously lower gauge or a buggered plug,) that choke point reduces the amount that gets through, so the device draws even more, so even though your unit says it draws 1500a, if it is dealing with something like this it your breaker could be receiving a much higher draw, which is causing it to trip your breaker.