Generator Question

[Wayne Clamp]

This past summer we bought a 27FB International Onxy. It has two air conditioners (heat Pumps) a convection microwave and the rest of teh standard stuff. My question is regarding the purchase of a generator. O by the way we live in Texas where heat can become somewhat problematic during the summers (sometimes the winters as well) thus i was to insure we can run both A/Cs, microwave, TV and anything else we might wish to. So with all the enlighted folks around her any advise on this subject

Wayne Clamp

[AnnArborBob]

I'm curious to see the responses you get to this question. I suspect you will be amazed at what it will take to accomplish your stated goal of running both AC's and the microwave together off a generator. Hopefully Lewster will see this post and respond to it. He is one of the real experts on the forum when it comes to electrical issues.

[SteveH]

Your trailer I'm sure is 50 amp service, and to run Everything at the Same Time would take a 12,000 watt generator. That would be two 50 amp legs at 120 volts, but if you were a little conservative, like not running the AC, the microwave, and the water heater all at the same time, you could get by with 7500 watts running both AC's.

Is your tow vehicle big enough to haul such a generator?

[lewster]

Actually, a 7500 watt generator (full rated watts) will do both A/C's and the microwave. I used one extensively in a 40' diesel motorhome that I lived in for 5years.

A typical roof A/C runs on 16 amps (2000 watts) but needs up to 55 amps of transient current to start the compressor. The demand drops back to 16 amps once it starts.

I remember using all 3 simultaneously without issue. The new Onan Quiet Diesels that most MoHos use are now 8000 watts, but most also now have residential fridges.

I also know folks with large 5th wheels that have integrated 5000 watt generators that still run both.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[slowmover]

The folks working gate guard positions in the Texas oilfield are often or usually provided with 25kw trailer mounted diesel gensets.

It's difficult to make an RV that is not bus sized & built to have genuinely adequate power plants.

The smaller the genset, the more often service is required, and operational hours are lower (time to engine failure).

Whatever is the happy medium is itself not portable and needs an comparatively enormous fuel tank.

It's best, IMO, to find afternoon shade for the TT and run only one AC most the day outside of the genuine afternoon heat.

If one wants a genset which is "portable", that is.

A pickup truck in 1T size fitted with a service body modified to permanently mount an ONAN 8k genset to fit all safe operational parameters would be great to have.

When I win the lottery, I'll have it built and have Panama Red charge admission to touch it based on Sphinx-like questions.

[Wayne Clamp]

Thanks for your response. As you can tell I know very little about electricity. I have been considering the Honda eu7000is. It appears, to me, as it has 30amp RV plug that no matter that it has a 7000 surge that it would matter little as without the 50 amp RV plug it would have only one leg to the 30 amp thus usage would be very limited and without the 50amp through two available 110 lines to make the 50 amp work it would be somewhat useless. Like i said i know little about electricity but it seems to me unless the generator comes with a 50amp RV plug connection (which i have been unable to find an inverter generator with a 50 amp RV type plug) the larger generator would be no better than the smaller generator wite the 30 amp rv plug. Thanks seeing as i am totally confused.

[SteveH]

Most 50 amp to 30 amp adapters tie both of the legs together so you CAN power everything in the coach. You just don't want to draw too much at a time by having too much on at a time. Worst case, nothing horrible should happen, just tripped breakers.

[Boxite]

"nothing horrible...just tripped breakers".... That's not right.

Trying to run AC units with too small generator can result in overloaded generator and burned up AC compressors. Ex$pen$ive.

[SteveH]

Comes down to the definition of the words "should" and "can", doesn't it?