have a TT 28ft with 30amp service... Have used the TT many times in the winter in vegas etc.. even with the A/C (13500) we were always able to use the micro with no problems. .... Last week our house A/C broke down (compressor) and we have been living in and still living in our TT in the back yard. Temps here in Az are about 115 daily and the A/C in the TT of course runs constantly. ....Now my question is that when we use the microwave now it runs for a few minutes and than the main breaker trips which it never did in the cooler weather... could this be happening because the temps are so hot now and the A/C is working constantly or maybe another reason? We use our coffee maker with no problem if that helps.Thanks for any suggestions....

I would assume you are using an extension cord to power the trailer? If so what is the length and gauge of the cord? There is a good chance the voltage dropping across the length of the cord is causing the A/C to pull more current and thus tripping the breaker when other items are used. Even if you have installed a 30 amp pedestal, that installation could prevent you getting a full thirty amps at 120V depending on the wiring and length from the house breaker box. Measure your voltage at other outlets when the A/C and Microwave are running and see what your voltage is. I would guess it is dropping below 110V.

What kind of outlet are you plugged into, regular 30 amp, or 15 amp house hold outlet?? Any extension cords?? If you are plugged into a 15 amp outlet, and/or using extension cords, there is your problem.

coffebreak wrote:Temps here in Az are about 115 daily and the A/C in the TT of course runs constantly. ....Now my question is that when we use the microwave now it runs for a few minutes and than the main breaker trips which it never did in the cooler weather... could this be happening because the temps are so hot now and the A/C is working constantly ...Absolutely. As exterior ambient temps rise so too does compressor head pressure, which in turn means it's drawing more current than it would at lower temperatures.

At those temperatures my Dometic 13500 draws 1900 watts. Add the fridge (325 watts) and the microwave (1570 watts in my case) and the total is far more than 3600 watts.A 30 amp service is intended to provide only 24 amps continuous. To translate that to watts multiply by 107 = 2568 watts. (the minimum safe voltage).

eHoefler wrote:What kind of outlet are you plugged into, regular 30 amp, or 15 amp house hold outlet?? Any extension cords?? If you are plugged into a 15 amp outlet, and/or using extension cords, there is your problem.This....

Microwave trips main breaker??? | Good Sam Community

pianotuna
Nomad III
Aug 05, 2018
At those temperatures my Dometic 13500 draws 1900 watts. Add the fridge (325 watts) and the microwave (1570 watts in my case) and the total is far more than 3600 watts.

A 30 amp service is intended to provide only 24 amps continuous. To translate that to watts multiply by 107 = 2568 watts. (the minimum safe voltage).
SoundGuy
Explorer
Aug 05, 2018
coffebreak wrote:
Temps here in Az are about 115 daily and the A/C in the TT of course runs constantly. ....Now my question is that when we use the microwave now it runs for a few minutes and than the main breaker trips which it never did in the cooler weather... could this be happening because the temps are so hot now and the A/C is working constantly ...

Absolutely. As exterior ambient temps rise so too does compressor head pressure, which in turn means it's drawing more current than it would at lower temperatures.
eHoefler
Explorer II
Aug 05, 2018
What kind of outlet are you plugged into, regular 30 amp, or 15 amp house hold outlet?? Any extension cords?? If you are plugged into a 15 amp outlet, and/or using extension cords, there is your problem.
accsys
Explorer
Aug 05, 2018
I would assume you are using an extension cord to power the trailer? If so what is the length and gauge of the cord? There is a good chance the voltage dropping across the length of the cord is causing the A/C to pull more current and thus tripping the breaker when other items are used. Even if you have installed a 30 amp pedestal, that installation could prevent you getting a full thirty amps at 120V depending on the wiring and length from the house breaker box.

Measure your voltage at other outlets when the A/C and Microwave are running and see what your voltage is. I would guess it is dropping below 110V.

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Microwave trips main breaker???

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