2 a/c units on 1 gen?

BB_TX wrote:

Sorry, but I don't use a 50 amp cord on 30 amp service. I use a 25' Marinco 30 amp power cord with a 50 amp connector on the trailer end and a 30 amp plug at the shore power end instead of my 50 amp cord with a 50/30 dogbone.

In your case, the 30A breaker on the shore power side OR generator breaker will pop before your 50A main breaker, therefore protecting your 30A shore cord from overload..

But once again, the 30A breaker or even the breaker in your gen are thermal/magnetic trip. The thermal trip once you get to 80% continuous for more than a couple of hrs will trip much easier as the breaker warms up.

You shore power cord even though it may be 10ga and rated for 30A, does indeed dissipate heat as you draw power, the more power drawn, the more heat it must dissipate.

The same insulation that protects you from touching live electrical wires becomes a insulator of heat. Making it difficult for the copper wire to dissipate any heat build up over time near full current rating. So, it is normal for a continuous heavy load to heat up your shore cord more than enough it will be warm to touch.

Uninsulated wire can handle more current for a longer time than insulated wire in the same wire gauge.

Heat dissipation and heat build up are the reasons why non insulated open air 10 ga wire can handle more current over a longer time than 10ga wire with insulation..

Ive always needed 5000watts or more to power (2) roof top A/Cs in hot weather, in fact the best situation was using a 6500 watt Onan

Just an observation here.
2 weeks ago in 95° temps I was running the rear a/c in our 5er which is 15k btu off my gen using the 20 amp outlet. I had to use a 50ft extension cord and an adapter to the 50 amp power cord because the gen is too heavy to lift out of the truck bed by myself.
The gen ran the a/c with no problem. It did pull down quite a bit at start-up but then ran for 7+ hours until I shut it off. It still had about one gallon of gas left.
Obviously it would best without an extension cord but it worked just fine.

Hummmmmm. Why do people assume that the wattage (capacity) of a given generator means that it will provide that wattage at ALL temperatures, altitudes, and humidities. This is simply not true. Generally, (unless you are turbocharged) as the temperature, elevation, and humidity go up, rated output goes down. That's why some people can get it to work, for some people it works, . . . . sometimes, while, others can't get it to work at all. Everybody isn't in the same location, on the same day, at the same time.

It's true that sometimes the breakers/wires/plugs can't handle the load, but sometimes the genny can't produce enough horsepower to generate the wattage either. (which can cause conductors to overheat)

Chum lee