Proper generator size

[NH_Bulldog]

There are pros and cons with propane as a generator fuel. In general, propane is less efficient than gasoline, so you use more and get less out of it. On the upside, propane produces fewer harmful emissions than gas, and doesn’t get “stale”. Most home stand-by generators are either propane or natural gas depending on what’s available, party for convenience, party for reliability.

In the end it comes down to personal choice which is easier or more convenient to carry, or purchase or is more cost effective. Having a choice with a dual-fuel unit is attractive as long as the cost difference is worth it.

[gearhead]

71 yrs., 3 back surgeries, 5'7", 168.
2 Honda 2000's with IPI/Berg long run kit. 2 new Champion 4650 inverters, 100# each. Long 50 amp extension cord.
I load them in the truck with a Harbor Freight engine hoist. Don't unload them until we get back home.

[Winnie2020]

Originally Posted by JRTJH

For a 30 amp trailer, I'd look at a 3200-3400 watt INVERTER generator. There are some "open frame inverters" on the market, but they are not as quiet as a "closed frame inverter".

The "gold standard" is Honda or Yamaha. Plan on well over $1000 for either unless you luck out on a used one on Craigslist or EBay. Champion makes a good 3200 watt "basic inverter generator" as does Harbor Freight, WEN, General Electric and Westinghouse. I'm sure there are lots of others as well.

To me, the key is a "closed frame inverter" about 3200 watts from a company or a retail outlet that can service it if you do have problems. If you look at the HF Predator series, make sure you get the extended "exchange for a new one" warranty. It's definitely worth the money for a 2 year warranty rather than the 90 day warranty that comes standard.

I was researching this very issue this morning for the same trailer (2021 model) as the OP's trailer. There is only one A/C unit that comes installed from the factory. I stumbled across a DuroMax Inverter generator (XP4500iH) that produces 3,600 running watts on gas and 3,240 on propane. I'd planned on going out to storage today to pull the appliance manuals in order to calculate running watts for the electric appliances but perhaps someone here can answer:

1) With the AC running, does the AC consume 100% of the 30 amps or is there room to run the TV, microwave and a few lights at the same time?

2) It sounds like from multiple sources, that an Inverter is the only way to go. Comments?

[gearhead]

With a 30 amp trailer hooked up the 30 amp pedestal in a campground, in my opinion, you should be able to run about everything. Running the A/C, microwave, toaster, and electric coffee pot might max it out though, but maybe not.
An inverter produces a much cleaner sinewave. Important for electronics.

[JRTJH]

Originally Posted by Winnie2020

I was researching this very issue this morning for the same trailer (2021 model) as the OP's trailer. There is only one A/C unit that comes installed from the factory. I stumbled across a DuroMax Inverter generator (XP4500iH) that produces 3,600 running watts on gas and 3,240 on propane. I'd planned on going out to storage today to pull the appliance manuals in order to calculate running watts for the electric appliances but perhaps someone here can answer:

1) With the AC running, does the AC consume 100% of the 30 amps or is there room to run the TV, microwave and a few lights at the same time?

2) It sounds like from multiple sources, that an Inverter is the only way to go. Comments?

Dometic recommends that a single 13.5 or 15 amp air conditioner be operated with a generator rated for 3500 watts and two air conditioners be operated with a generator rated for 5500 watts. That takes into account starting amperage requirements, other amperage draws within the trailer and voltage drop from the generator to the trailer power system. Until the popularity of inverter generators made them the "most commonly used type" most people had "contractor generators" that were loud, often smelly and burned lots of fuel. They were most often located as far away from the trailer as possible (to reduce noise and heat) so voltage drop was a more significant factor "back then" than now.

When you look at your 3600/3240 watt generator, and analyze the trailer distribution system, you come up with these "numbers":

The Air Conditioner circuit breaker is a 20 amp breaker. 20 amps at 120 volts is 2400 watts. So, the air conditioner will not draw more than 2400 watts of power (except for theoretical power during startup)... In reality, the compressor will draw around 12.5 amps (1500 watts) and the fan motor will draw around 2.5 amps (300 watts). That 1800 "running watts" is significantly variable, depending on the temperature, the "freon charge", compressor temperature and so many variables that it's "impossible to pinpoint an amperage draw for calculating purposes"... in other words, every trailer will be slightly different, but speaking in generalities, around 1800 watts should be a good guess.

With 3240 watts on propane power, that generator will produce a minimum of 840 watts of "surplus power" when the air conditioner is running.

The converter/charger in your trailer is probably a WFCO 55 amp unit. 55 amps at 12 volts is 660 watts.

So, with the air conditioner and the converter/charger operating at "full power" you'll come very close to maxing out that generator when operating on propane. When operating on gas, you'll have a "wee bit of surplus wattage"....

As you can see, "doing the numbers" is the best way to take into account what you need and what you have.... In "real world use" you'll seldom have 20 amps used by the air conditioner and 55 amps used by the converter, so there's a "built in fudge factor" when calculating requirements using the maximum potential....

It's the same "theory" when calculating a tow vehicle or a trailer size: Use the maximum/worst case scenario and you'll always be "on the safe side" of your numbers...

[B-O-B'03]

We are coming into our 7th season with a Champion 3100/2800 watt inverter generator.

It will start and run the Dometic 15K AC unit as well as run the mini-fridge in the outdoor kitchen, the converter to keep the batteries charged and the fridge inside the camper (absorption style).

I am really happy with it and used it last winter during the "stormagedon we had here in TX. It basically ran for 4 days straight, refueling it every 6 hours.

It has never failed to start by the second pull and it generally starts on the first.

At almost 68 years of age, 5'6" and 165 pounds, I can load it in the bed of the truck by myself.

For a plain-Jane version, it does everything I need.

-Brian

[nitrohorse]

I read where China is producing small 3k watt diesel generators. They are supposedly good on fuel consumption. Not sure how noisy they are though.

[JRTJH]

Originally Posted by nitrohorse

I read where China is producing small 3k watt diesel generators. They are supposedly good on fuel consumption. Not sure how noisy they are though.

We bought a "china made diesel 4500 watt generator" at Sam's just before Katrina. We'd just built a "gold star all electric home" and with the hurricane, we were sure we'd need power. It weighed about 350 pounds, was significantly louder than any generator in the neighborhood. It was "economical to run" but no matter where we sat it, even behind the pool building, we could hear it over the TV and air conditioner anywhere inside the house.

Unless they've improved their "noise abatement engineering" on cheap china diesel generators, I'd urge you to "listen before you buy"... Just shipping to return it would likely be more than the cost of a pair of Champion 2000 watt generators and a parallel kit. And I know the Champions make a LOT less noise.....

[gearhead]

I bought 2 Champion 4650 inverter gens last year. They are amazingly quiet.