What is the correct of a 30 amp main power cord?

[Lee012]

We have recently purchased our first Airstream. It is a 1981 Excell II, 31 foot rear bath. The main power cord has been cut and reconnected, splice looks professionally done. The length of the cord now is about 15 feet. Should I buy a new cable and install new or buy an extension for longer runs to a plug?

[richard5933]

If the cord is 15 feet long now, in my experience in commercial campgrounds you'll likely need the extension cord at least half the time, maybe more. We have a 25-ft trailer with about a 30-ft cord, and there have been times when even the 30-ft cord wasn't enough.

My guess is that the previous owners spent a lot of time in one site and a shorter cord worked for them so they shortened it.

Would hurt nothing to use it as is for a season along with a 25-ft extension to see how things go. If you decide a longer cord would be better you can always swap out for a new cord down the road. If the shorter one works, then you're set. Either way, that 25-ft extension cord is something you should carry with you since there will always be a pedestal at the far reaches of a camp site and it will be a bonus to have it along. An extension for water & electric can make the difference between being in the ideal part of a camp site and having to compromise to reach the utilities.

[Bill M.]

That age trailer I would replace the cord. Cord was 25 ft I think. I bought an extension from Amazon.

[Lee012]

Thank you for the responses. I just bought a replacement 30 foot cable online and also bought a female receptacle end to make the old cord into an extension if needed.

[richard5933]

Originally Posted by Lee012

Thank you for the responses. I just bought a replacement 30 foot cable online and also bought a female receptacle end to make the old cord into an extension if needed.

Great solution.

[foobar]

Originally Posted by Lee012

Thank you for the responses. I just bought a replacement 30 foot cable online and also bought a female receptacle end to make the old cord into an extension if needed.

That is an excellent use of resources. Recycle the old cord into an extension that you use "as needed".

As long as the outer cladding on the old power cord is intact and not brittle/splitting from long term UV exposure, then it should be ok to use.

[Gene]

Good solution.

You can test the old cord with a multimeter to see if it is still good. First look at the cord to look for breaks in the rubber exterior cover, damage to the exterior insulation, damage to the plug. The braided conductor inside can gradually break down, but that depends on quality and how it was treated. They do last quite a while, but really bad treatment could break the strands of wire inside. I could stumble my way through testing one, but best to use the internet with a question like, "how do I test 30 amp power cord with multimeter?"

If you prefer stumbling, plug in the old cord once it is removed and test for voltage and ground at the other end after testing the the 30 amp receptacle. There should be a slight voltage drop, but very little at 15'. There are tables on the internet to see what exact voltage drop would be at 15'. If my memory still works, a 30 amp cord should be 10 gauge conductor for each lead.

Conductors inside should be color coded—black for hot, white for common (people call it ground, but it isn't), green or bare for ground. If you had 50 amp cord, there would be second hot wire and it would be red.

Some campgrounds have poor grounds or reversed polarity. Good to test them for that too.

[lemley]

I have an ‘88 Excella.

It’s summer in Texas. That means running the AC a lot. Just before our trip last week I noticed that the plug on the end of the cord had melted. Again. Happens every couple of years. No problem. I keep a spare.

But while in the middle of putting the new one on it finally hit me. These conductors are not copper colored. They are blackened. I cut back another foot. Still blackened. I cut back another 10 feet. Still discolored. I had to get about 3 feet from the bumper before I got clean copper. It seems that over 34 years the combination of high current and moisture had degraded most of the cable. I now have a new cable.

So I think you avoided trouble by replacing the cable. I’d be cautious about using the old cable. The end where you are putting the female connector may look pristine. The other end may be hiding degradation. The times I’ve had the ends melt they generally pretty well destroyed whatever they are connected to.

IMHO it will be hard to detect the degradation with a simple resistance test. Resistance will be best measured by measuring voltage drop under load. I now check the temp of the cable and connection from time to time with the AC running. It should be close to ambient temperature (if it’s in the shade).