Why Is My 2002 Holiday Rambler Air Conditioner Tripping a Breaker?

Power Supply

• If the breaker trips only on generator power, but not when the RV is plugged into shore power, this suggests the generator is failing to provide adequate voltage or is running at the wrong hertz frequency. Running a heavy-draw machine such as an air conditioner on too-low voltage or with a wrong frequency has the same effect as increased resistance; the breaker trips because it overheats. Have the generator tested for operation under load. If the breaker also trips on main power, the issue is at or downstream of the breaker.

Spiking

• Air conditions draw more electricity immediately after being switched on than when running, a phenomenon called “spiking.” A 12-amp unit can spike at 16-amps at start-up, and this can be an issue in twin-A/C RVs. If two air conditioners are both rated at 15 amps, they could operate simultaneously and not trip a 30-amp breaker. But if one is already running when the second is switched on, the spike could momentarily increase the demand above 30 amps and blow the breaker.

Weak Breaker

• When handling breakers, always make sure the Holiday Rambler is unplugged from shore power and the generator is not running. Always explore the simplest option first: Breakers sometimes go bad, and each time they trip the value needed to subsequently trip them again decreases. Exchange the breakers that protect the front and rear air conditioners; if the tripping issue is also swapped over, then you have a faulty breaker and a replacement should solve the problem.

  Another consideration is that breakers are heat sources. With a number enclosed in a small breaker box and a great many appliances running simultaneously, the heat can build up to a level where the breakers misinterpret the temperature as an indication of failure and protect their circuits by opening. If the breaker box is in a cabinet, simply leaving the breaker box door open could resolve the issue. But this is not a permanent fix since the connections are dangerously exposed. The experiment will show whether increased ventilation is likely to solve the problem.

A/C and Harness

• If the problem remains after exchanging the breakers -- meaning the new breaker trips as frequently as the old one -- then the problem is within the air conditioner or the A-C wiring harness. Use a multimeter in accordance with the manufacturer’s instructions to determine if there is a short in the harness; test the live, neutral and ground wires for continuity. Loose connections cause increased resistance, and -- as noted above -- this can cause breakers to trip. If the harness is without issues, the problem is in the air conditioner unit. Diagnostics and repair should be left to certified professionals.