30 or 50 Amp?

[beckettnole]

I am restoring a 31ft 1965 Airstream and am running new electric at the moment.

Should I do a 50 or 30amp system?

I realize most campgrounds are 30 but I am thinking I can grow into the 50amp system?

I am new to this world so thoughts and advice are greatly appreciated.

[Al and Missy]

I would probably go ahead and put in 50 amp. As I understand it, 50 amp service is really two services, a 30 amp service and a 20 amp service. Assuming you are putting in one AC unit you could run the cable to the location of a future second unit and just not put in the breaker. You could put in a 4-wire shore power cable but terminate it with a 3 pin plug for 30 amp service and change the connector when/if you add the second AC unit or something else on the 20 amp input circuit.

Al

[markdoane]

A 50a service is not a 30a and a 20a. It is a full 50a 120/240v split phase connection which will provide you with the equivalent of 100a at 120v.
I put 50a 120/240v service in my '59 and love it not because I have two air conditioners, but because it lets me run the air conditioner and the microwave and the water heater and the waffle iron all at the same time.

[TRIPPPIN]

Definitely 50amp for the extra initial cost it would only be a few bucks and you wont regret it if really needed in future.

[DaveFL]

I did the upgrade and it was worth it, but I have to say I didn't do it for 50 and 50 amps. All I wanted was what my needs were: two a/c's and no need to touch the switch that allowed having two with 30 amps. We still alternate the use of one at a time 99 percent of the time, great for that 1 percent when we stop to cool the whole place down fast with two.

[Al and Missy]

Originally Posted by markdoane

A 50a service is not a 30a and a 20a. It is a full 50a 120/240v split phase connection which will provide you with the equivalent of 100a at 120v.
I put 50a 120/240v service in my '59 and love it not because I have two air conditioners, but because it lets me run the air conditioner and the microwave and the water heater and the waffle iron all at the same time.

Thanks for the correction. I have read many times that the RV service was not 120/240, but two separate feeds of 120 from the same phase, so line to line would be zero volts. I went looking for those references and could not now find a single one. As you said, 50 amp service is 120/240 consisting of two hot lines, one from each phase, a neutral, and a ground, fed from a dual 50A breaker.

I apologize for providing bad information. I'd still wire it up for 50A, even if I didn't plan to use all of it immediately.

Al

[m.hony]

50 amp is the only way to go.
You cannot run a hair dryer and a/c at the same time on 30 amp.
You cannot run a hair dryer and microwave at the same time on 30 amp.
You cannot run a microwave and a/c at the same time on 30 amp.
You can run all 3 at the same time on 50 amp.

[SuzyHomemakr]

If had been doing an inner skin off remod on mine, I would have gone to 50A. Even if you aren't really using it, you can always put a 30A adapter on your shore power plug and loose nothing. Start summer camping in Florida, suddenly a twin A/C system starts sounding mighty nice!

[rvb]

I have seen some retrofit installations where a second roof A/C was added in the bedroom and wired to it's own 20A circuit with a dedicated power cord. If 30A is not available the bedroom A/C can be run from standard outlet. When 30A is available they plug in both the 20A and 30A and run everything.

[m.hony]

I have seen that too.


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[Bill M.]

Most campgrounds are 50 amp. you can run a 50 amp on a 30 amp with a connector. I see no reason not to go that way.

[m.hony]

But...
When you use a 50 to 30 adapter on a 30 amp pedestal you still have a 30 amp trailer.

[ijustlee]

No question about it, I'd go with the 50 amp set up if I was doing it.

[Air83]

50 amp..... This is hard to explain but....
When I installed a 2nd a/c I rewired the trailer to run thru everything thru 50amps service.Then ran a 2nd wiring thru just the back a/c to a 2nd breaker box and a heavy duty 20amp electric cord. If I'm at someone's home I can run everything inside on gas (refrigerator, hot water, stove) and then turning off the 50amp breaker to that a/c and use the 2nd breaker box- 20amp cord to run my a/c. NOW in saying this you CAN NOT plug in the 50amp shore service and the 20amp at the same time. This will blow up your friends house and your trailer or pop every breaker in the house. I would suggest a professional... It works great and I show off my wiring at many rallies..

[Tater]

50 amp will give you more flexibility with appliances and a/c.

[beckettnole]

Thank you all! I assume I will have to get a 50amp capable inlet, shore power cord and an adapter for 30amp hookups?

[jimfa440]

If I purchase a new AS with 50 amp service, can I use a dogbone (50-30 amp) and plug into a 30 amp service and operate most things except both air conditioners.

[The Boot]

following on jimfa440 question

what is the the boards opinion on the adaptor that is 50 amp to 30 and 20 amp at the same time?

moving up from a 30 amp to 50 amp trailer.

[jeffmc306]

Jimfa440 and The Boot - simple answer is “yes” - you can use a dog bone or as 69SoulShine recommended, a straight 30-50 adapter in Post#10. His reasoning is it keeps your EMS off the ground when the pedestal is short. You can connect multiple adapters together to get to the desired plug just know each one adds a potential resistance point if they’re loose.

If you’re getting a new AS, they provide a 50 to 30 dog bone. Make sure to invest in a good EMS like a Progressive Industries EMS-PT50X

By the way, I swapped out the monster 50A cord that came with our AS to a right-angle plug Valterra Mighty Cord. Much easier to handle compared to the Anaconda that comes from AS.

[Mollysdad]

I can't imagine a 1965 Airstream with two A/C's.
However, as many suggested, install the 50 amp service. It doesn't show, and you'll forever be glad you did.