I'm preparing to purchase a 5th wheel that has a 50 amp service. We'll be taking a dry-camping trip in August and I need to get a portable generator that will work. For my dry camping we'll mostly be using the A/C, water pump, and a lights. I can keep the fridge and hot water heater on gas operation. I've had a 30A TT for many years and I've not dealt with 50A systems. Pardon the ignorance but please help me clear up a few things.1) Does the 50A work on 240volt or 120volt?2) If 240volt, is it 25A per hot leg?To get a full 50A service I believe I would need a 6000 Watt generator (50A x 120V= 6000W). Generac has a 6500W (8000W startup) generator that is within my budget. The kicker is to get 6500W it uses the 240V plug that supplies 27.1A to each hot leg.Will that generator work?I just want to be sure I don't get burned buying something undersized. Previously I had a Generac GP3250 for my 30A service TT. I thought it was fine since 3250W would give me 27A. It wasn't until after it failed to run my A/C that I realized it was rated for 27A total and delivered 13.5A per leg of the 240V plug and only 13.5A to the 120V outlets. On a cool day that was okay, but in the hot Tennessee sun the A/C kept tripping the breaker each time it tried to kick in.When not using the generator for dry camping I'll keep it around to backfeed my house in the event of a power outage.Thanks,KJ

50 Amp is 220v with 50 amps per 120v leg. With the right adapter(s), you can plug into regular 15amp outlet, 30amp RV outlet, 30 amp 120v twist, 30 amp 220 twist, or a 50 amp 220 twist.http://www.park-power.com/en/products/detachable-power/adapters/generator-adapters

RV electric 50a websiteRV 50a wiring diagrams

50A RV supply is 50A 120/240V supply, 50A on each leg, or 12 kW total power. It's exactly the same configuration as a standard household electric range (with a four-wire connection, as opposed to the old 3 wire connections that are in some existing buildings).Your generator should be sized based on the maximum load you need to support at any given time rather than based on the ratings of the RV input power. For a 30A RV, these are often pretty close to being equal; but for most 50A RVs, the electrical needs are well under the electrical supply limits.A 4 kW or so generator wired for 120V (so 120V at 35+ amps) would serve you just fine when running one air conditioner with a decent cushion to spare. The key here is that it's 120V, so you aren't limited to half power per leg. A standard 30A to 50A RV adapter would presumably be needed; this simply connects the one hot from the 30A supply to both of the hots on the 50A supply, so the full generator output is available to start the air conditioner. A somewhat smaller generator could suffice, too, though I can't really say exactly where the cutoff would be.

2oldman wrote:RV 50a wiring diagramsThat is helpful. So a total of 12,000W can be delivered to the breaker panel.The Generac GP6500 has a NEMA L14-30R 240V plug. The 5er we're going to purchase has a single A/C unit. Given the explanation from that web site, it seems the 6500W genny might work:"In the case of the rest of the 50 amp RV's, 250 volts is still supplied to the coach just like your home electrical service but typically one side of the line is used for all the 125 volt appliances except the rear AC and the other side is used for the rear AC only."Thoughts?KJ

DrewE wrote:A 4 kW or so generator wired for 120V (so 120V at 35+ amps) would serve you just fine when running one air conditioner with a decent cushion to spare. The key here is that it's 120V, so you aren't limited to half power per leg. .....That was my GOTCHA on the previous generator. It was rated for 3250W running, but I didn't see until later that wattage was divided between each leg of the 240V. So, my actual max available amperage on 120V was 13.5A which caused my A/C to bog and eventually kick out the breaker on the genny.KJ

Portable Generator for 50 amp service | Good Sam Community

18 Replies

LIKE2BUILD
Explorer
Jul 27, 2016
Sandia Man wrote:
This Generac 6500 is weigh overkill for your 5er, it is too bulky for RV use at over 200# loaded with fuel not to mention it will roar when put to the task.

I'm seeing that now.

Sandia Man wrote:
You have a single AC unit thus any decent 3K watt or slightly more generator will work,

I'm looking now in the lower wattage range since I've read a bit more on the 50A setups.

Sandia Man wrote:
hard to fathom why the prior Generac 3250 watt unit wouldn't perform the task.

The GP3250 makes a TOTAL of 27 amps. However, that 27A is divided between each leg of the 240V plug, so on each leg or the 120V outlet the most amperage available was 13.5A. I had tested the A/C on a cool day at home and all was good. However, on a really hot day the A/C produced more load and that would cause the breaker on the generator to kick out.

Sandia Man wrote:
RVs with onboard Onans come with a 4000 watt genny for 30 amp and a 5500 watt unit for 50 amp rigs that have 2 AC units. Unless there are plans to add the second AC unit to your rig you may be wired for 50 amps but in reality 30 amps will run your rig fine.

I don't intend to add the 2nd A/C, so you're probably right. If I get a generator in the 4KW to 5.5KW range I should have more than enough power.

KJ
Sandia_Man
Explorer II
Jul 27, 2016
This Generac 6500 is weigh overkill for your 5er, it is too bulky for RV use at over 200# loaded with fuel not to mention it will roar when put to the task. It might be more suited as a backup to your house power, but not an ideal generator for RV usage.

You have a single AC unit thus any decent 3K watt or slightly more generator will work, hard to fathom why the prior Generac 3250 watt unit wouldn't perform the task. Since you were considering an open frame unit, the Champion 3500/4000 watt genny is both economical and proven.

RVs with onboard Onans come with a 4000 watt genny for 30 amp and a 5500 watt unit for 50 amp rigs that have 2 AC units. Unless there are plans to add the second AC unit to your rig you may be wired for 50 amps but in reality 30 amps will run your rig fine.

Inverter generators are more conducive to RV usage. They run quieter, are lighter in nature, provide clean power, and are fuel efficient by comparison. Champion has a remote start 3100 or 3500 version that will easily power 1 AC for about the price of a single Honda/Yamaha 2K watt unit.
LIKE2BUILD
Explorer
Jul 27, 2016
smkettner wrote:
Two air conditioners? Go with three Honda 2000 :B

No, it has a single A/C installed. However, it has framing and electrical provisions to add a second unit in the front.

Based on the explanation from the RV Wiring web page provided by 2OldMan it sounds like most 50A RV systems use one leg of the plug for the main A/C and all other systems and the other leg for the 2nd A/C unit.
time2roll
Nomad
Jul 27, 2016
Two air conditioners? Go with three Honda 2000 :B

http://durationpower.com/store/

A single large generator is going to be hard to call portable IMO.
LIKE2BUILD
Explorer
Jul 27, 2016
We agreed to purchase the 5er last night. I asked the owner about the 50A service and he said it has the 50A plug but front A/C unit is not in place. The roof vent in the front bunk area is framed in and a power line is installed in the ceiling to have an A/C dropped in, but the rest of the RV will operate fine on a 30A supply.

Thanks for all the help deciphering this. Hopefully I can find the right generator soon.

Kj
LIKE2BUILD
Explorer
Jul 26, 2016
Bumpyroad wrote:
doesn't the 5er offer a generator as an option. seems more practical than horsing around with a heavy "portable". assuming you can park it close enough to supply your house in an emergency.
bumpy

This is a used 5er I'm buying so there's no option to add a generator on board.

KJ
rstanek
Explorer
Jul 26, 2016
I just purchased 2 eu3000i handi by Honda, parallel it gives me 50 amp, 6k for startup, it will maintain 44amps, 5200 watts, and they only weigh 78 lbs each and have built in handle and wheel kit.
Bumpyroad
Explorer
Jul 26, 2016
doesn't the 5er offer a generator as an option. seems more practical than horsing around with a heavy "portable". assuming you can park it close enough to supply your house in an emergency.
bumpy
randallb
Explorer
Jul 26, 2016
50A RV is two 50A legs @ 120V. If you do the math your generator should be able to deliver up to 12,000W of power. You seldom will find a RV with this much generator. My 08 HR came equipped with a Onan 5.5 and it was always enough for what we would run when not in a RV park. I also set my house up with an emergency 5500W propane generator as I am only concerned with power to the fridge, freezer, well pump and a few outlets. Determine what you want to run, add up those items max power demands and purchase whatever meets these requirements. You never run everything in the RV at once.
Randy
the_bear_II
Explorer
Jul 26, 2016
I had a Onan 5500 watt generator installed when we ordered our 50amp 5th wheel. It would run everything including the air conditioner and the washer or dryer. After about 10 years it died and I bought two Honda 2000i generators with a parallel kit to get 50amps.

I actually like the Honda setup better for the following reasons:
> They are portable so I can use them wherever I need them...at home, on a job site or for the RV.
> If I don't need both I only carry one
> When both are running they are quieter than the Onan was
> Fuel consumption is less than the Onan even with both running

A couple of drawbacks:
They have to be secured really well to prevent theft
Manual start (the Onan was remote start) Not a problem unless it's a cold rainy morning and your wife wants waffles instead of cold cereal.

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Portable Generator for 50 amp service

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