[Festus2]

If you have a 30A circuit, then running the A/C and a microwave at the same time will trip your breaker. Don't forget that if you have your HW heater set on electric, that is a heavy draw on your circuit. The converter, which one doesn't really think much about, is also a draw so it doesn't take much to "run out of amps". In a sense, the 1500W heater isn't really "running all by itself" if you count the converter and the HW heater. You should be able to operate a 1500w heater if you don't have other items going at the same time - coffee pot, frying pan, microwave, etc.

There really isn't anything wrong but having a 30A circuit does place some restrictions on the number of things you can have running at the same time.