4000 Watt Generator

The idea of running a front AC during the day and the rear to cool the bedroom at night seems good. Running both AC's plus microwave and other stuff might be iffy with the 4KW vs the 5KW, need to monitor the line voltage to assure that it doesn't dip too low with potential damage to AC units. If the dealer has a rig with two air conditioners and a 5KW generator, ask them to demonstrate it and verify adequate line voltage. We use a simple plug in line voltage meter.

It's a lot to consider, I guess we just have to see what we can afford. The payload has also become a very big concern. We certainly don't want to overload the weight capacities.

Thanks for all the help

Sam Spade wrote:


There are too many assumptions in here to make this good advice.

In general, you can't have two air conditioners with 30 amp service.....and you can't run two off of a 5K generator either.

But that depends on what size the A/C units are.

I can't imagine that they make units small enough to run two off of 4KW.

She had posted in the other thread the option of two AC units and 50 amp service for the RV. That is the package deal she mentioned. My thought is if you go that way, which she should, go with the bigger generator if indeed it is an option. She mentioned later she would only run one AC on the generator, but I still think she should cover all possibilities with the larger generator if it's feasible and she goes with the two AC units and 50 amp option. At least with the power consumption of roof AC units I've had, I think the 5000 would run both as general rule. A little more wouldn't hurt if available.

Our 34' has 2 AC's. Front is 13.5. Rear is 11.0. Even in 100° both AC's do not run all the time. It has 50 amp service. This allows us to run everything in MH without concerns of tripping a breaker. 50 amp service is actually two 50 amp lines. This gives MH a total of 100 amps.
Does Nexus connect both AC's to the ducts? This makes a difference in how well rear AC cools RV. As other have stated, We use rear AC during the day to cool and front AC to cool at night.
Adding a second AC and 55k generator is going to take away some load capacity on a E450 chassis.

We have enough experience with 30 amp to know that we are limited. We would probably never run both A/C's on generator, I would never boon dock in the middle of summer. It is just that when you upgrade the unit to 2 A/C's, I think, (but don't have the paper work with me) that it is 2 13.5 units.

We usually use the LR A/C during the day, at night shut it down and run the one in the bedroom. Even if they are both running, it would never be off the generator.

tpi wrote:
I was reading your other thread on the AC units. I highly recommend the second AC. If you get the two AC, I'd go with the 5000 watt if optional. This will keep both ACs going effortlessly, and may allow microwave at same time. You may be able to run two ACs on 4000 watt, but it will be close without guarantees.

There are too many assumptions in here to make this good advice.

In general, you can't have two air conditioners with 30 amp service.....and you can't run two off of a 5K generator either.

But that depends on what size the A/C units are.

I can't imagine that they make units small enough to run two off of 4KW.

The 4000 Watt, aka 4KW, is able to power an RV as if plugged into 30 Amp shore tie. 30 Amps at 120 Volts is 3600 Watts, so a 4000 Watt generator offers a little margin.

I was reading your other thread on the AC units. I highly recommend the second AC. If you get the two AC, I'd go with the 5000 watt if optional. This will keep both ACs going effortlessly, and may allow microwave at same time. You may be able to run two ACs on 4000 watt, but it will be close without guarantees.

Thanks for all the information. It's great to have all this experience in one place to help with hard decisions. This will help us make our decisions on purchasing a new rig. We have camped for over 20 years, but only in a 5th wheel. We carried a generator, but it was strictly for essentials, so this is all new to us.

I have the 4000 watt Onan and it easily runs the 15K BTU air conditioner. In fact on occasion I've run both the air conditioner and microwave at same time without issue.