Using a 30A cord with a 50A shore power terminal

[Msmoto]

@Gnorts

Thanks, i will reconfigure this to comply....

[switz]

If one looks carefully at their power panel with a factory 50 amp service to support dual air conditioners, it is a 240 VAC box with two 120Vac busses. While no 240Vac circuit breakers are used since all appliances and air conditioners are 120Vac, you should have a 240Vac main breaker. A four #6 wire cord with connectors that have three pins plus the grounding strap on the trailer end and four pins for the pedestal on the side are capable of bringing in two legs with 50 amp capacity on each one or supporting a total electrical load of 12,000 watts.

So that huge motor home with 50 amp service can run bigger air conditioners, washer and dryer etc with no issues.

So setting up the circuits properly, one would find an air conditioner on each leg and the water heater on one leg and the refrigerator on the other leg to balance the load. The power outlets could on one leg and the microwave on the other so the imbalance is minimal.

Some of the adapters for the four conductor 120/240 power cord can put the two legs together so that a 120Vac source powers both legs which limits the power draw to 5,000 watts on a 50 amp pedestal or 3,600 watts on a 30 amp pedestal.

Before plugging into a power pedestal, the user should verify whether there is a two pole breaker or single pole breaker for the desired plug. A voltmeter should then verify that the outlet has 120Vac or 240Vac if there is a four pin outlet.

[Msmoto]

50 Amp Connection.002 by Fantinesvoice.com, on Flickr

It would appear that what goes in to the Airstream from a 50 Amp shore line is 120v on each side and when read across the two hot poles, 240v. This is correct as the connection was running my moho for three years, reads as correct with my line monitors, and has given no problem. I would therefore have to conclude my 50 Amp to 30 Amp configuration as shown in the earlier photo, is indeed correct.

[JBinKC]

These adaptors cover all the bases for my 50-amp wired Airstream. I stay with the pudgy 50-amp cord to reduce clutter, overloads and line loss. And a surge protector heads it all up, which is a whole other topic.

[ghaynes755]

Here's a nice review of the setup. Easy to understand the 50 amp with its two legs. Also if you look at the 2014 AS owners manuals you will see usually 8 sub breakers, 4 on each side of the two 50 amp CB's in the middle. Easy to understand what is on each side.

FTLS - Electrical Distribution

[Msmoto]

Originally Posted by Msmoto

I have a 30 Amp Cord to which i have spliced in a 50 Amp female plug so i can directly hook up the trailer to my generator without the cumbersome 50 Amp cord, which i find a bit overwhelming. And, when I have my new cord plugged into a 50 Amp shore receptacle, here is what I get for readings. My query is: Have I done this correctly....experts?

Airstream_50_Amp_Receptacle to 30_Amp_Cord.001 by Fantinesvoice.com, on Flickr

So, after checking all the info I could, and very helpful was the post by ghaynes755, I hooked up the 30 Amp male plug into my 4000w generator, the the 50 Amp end into the Airstream receptacle, and obtained 14.4 v, and the a/c ran well, switching between front and rear to do a complete test.

As noted in the excellent article "FTLS - Electrical Distribution", when on 30 Amp it is running the entire 30 Amp over both legs of the electrical circuit.

So, the test went well, the generator running bout two hours with no problems.

[paiceman]

I use a similar set up but with two 2000 Honda's running in parallel. As you noted runs one A/C at a time, which is fine. If I just want to hit the batteries I run only one to charge them up if the solar is not doing the job.

Bud