Maximum length for 50 amp?

[napria]

Does anyone know what the maximum safe length for 50 amp of extension? In other words, we have a 30' cord we use for our electric hookup now. Can we add another 30'?

[rohrmann]

Sure. It's not really the length, but the expected load you will be placing on the cable. We were in Tennessee last year and had our stock 50 amp cable out, with a 30 foot 50 amp extension, with an additional, 30 amp cord which is 50 feet long, then plugged into a short 20 amp cord which was plugged into a 15 amp outlet in the cousin's garage. All those cables with the appropriate adapters, and we had no issues. Of course, we were only using a few lights and were basically keeping the batteries charged. Had the fridge and water heater on gas only and were not using the A/C. This setup would not work the microwave or hair dryer or any other appliance with much load. The usual way electric load and length of cable is described is, compare the size of cable to a water pipe, and the water to the electric load. If you want more water over a longer distance, you need a larger pipe. If you have 200 feet of 1/2 inch hose, you can only get a little water to flow because of the resistance of the small hose. The same is true with electricity and wire size.

[napria]

So we would want to run the microwave, refrigerator and tv/DVD player, plus lights and possibly both AC.

[CORattler]

quote:Originally posted by napria

So we would want to run the microwave, refrigerator and tv/DVD player, plus lights and possibly both AC.

Then you would want 50 amp anaconda all the way.

[DQDick]

We carry and extra 50amp extension cord and have used it from time to time. They're heavy, but need to be and as long as you're plugging it into a proper 50amp outlet you'll be fine.

[napria]

I'm definitely getting a 50 amp extension cord. The question is, how long is too long? I know you can't connect too much length or the cords will get too hot and present a hazard.

[Tom S.]

quote:Originally posted by napria

I'm definitely getting a 50 amp extension cord. The question is, how long is too long? I know you can't connect too much length or the cords will get too hot and present a hazard.

We have a 25 foot extension to match our standard 50 amp cord. I've only had to use it twice, but it sure came in handy when I needed it. First time, we were in Alaska and the campground had the power station at the front of the lot. We could have pulled in backwards (it was a drive through) but then the sewer and water would have been on the wrong side. Campground wiring was obviously laid out by someone who was having a bad day. Another time, we lost half a leg of electricity at our pedestal, so I used the extension to plug into the empty lot next to us.

[JandC]

We started with a 25' extension and probably end up using it at least two or three times a year.

[halfwright]

from
http://www.myrv.us/electric/pg/50amp_service.htm


15 amp 20 amp 30 amp 50 amp 100 amp

25 feet #14 #12 #10 #8 #6
50 feet #12 #10 #8 #6 #4
100 feet #10 #8 #6 #4 #1
The format will not keep the spaces in the list, but maybe you can read it. For 50 amps at 100 feet, you would need to use 4 gauge wire.

[halfwright]

quote:Originally posted by RonD

RV 50 amp cords use #6, you will never use a full 50 amps in an RV

How long are you talking about??

[Tom S.]

quote:Originally posted by halfwright

How long are you talking about??

RV Cords are 25 feet in length. As long as someone sticks with the cord that came with the RV and one 25 foot extension, they will never exceed the 50 amp rating. However (there's always one of those!), if the campground has exceeded code problems can and will occur. For example, if you are on the last site at the end of a run that is 200 feet from the power source, and the campground owner used #6 wire, you already have the capability of 50 amps at 240V reduced before you plug in anything. If it's spring/fall and you (and the other campers along the line) aren't running lots of stuff, you'll most likely never know, but if it's summer and 100 degrees, all those a/c units will definitely take their toll and could cause problems. That's one reason why a good surge protector that also monitors minimum voltage is important to have.