Please confirm what I think I already know

barchetta1 wrote:

Bumpyroad wrote:
Yesterday was running air, water heater and micro. 30amp main blew.

of course it did.
bumpy

Why do you say of course? RV should be designed for full load? Are you being sarcastic? Sorry can't tell.

EDIT: if you read the review I posted I think this personal nailed it. In my coach the 30amp main and 20amp AC are combined into one breaker. the heat created likely causes the main to pop early since it is sitting on top and taking the heat from the AC.

NO, they are not designed for a full load. A microwave is 750 to 1000 watts. the A/C is 1500 to 1600 watts, the water heater is about 1400 watts, and the fridge, when running on AC current is an intermittent load of 500 watts or so. You also have a power converter using 120v AC to make 12v DC to charge the batteries and run the light. These can be drawing several hundred watts also.

Basically, you need to pick what you want to use, and turn off the rest. If running the AC, then its OK to run EITHER the water heater or the microwave, but NOT both. In fact my motorhome, now sold, had an automatic load switch that allowed the water heater to run, until it saw load on the microwave circuit, at which time it shut off power to the water heater. When the microwave stopped, it again turned on the water heater. KEEP stuff turned off if you are not using it. Water heats very quickly in the tiny water heaters RV's have, so don't leave it on, turn it on, let it heat, use it, shut if off.

30 amps at 120 volts is 3600 watts. National Electric Code considers anything running continuously and anything that generates heat, such as an electric water heater to be a continuous load. Your total continuous load should never exceed 80% of your total, thus anything over about 2900 watts is too much, and you will eventually burn up your power plug on the end of your shore cord, and also have other issues in the electric system.

Charles