A good 100’ 50A extension Cord for RV

[edmck101]

I’ve been invited to stay in a friend’s 38’ Montana in Tucson for a few weeks. To reach his garage 50A service outlet I need to buy a 100’ extension cable. I’ve used one before in my RV life and I know they’re bloody expensive. Would it be cheaper to buy two 50A cords? Just wondering if it’s okay (safe) to use two cords rather and a long 100’ cable.

[Old Scout]

How heavy is a 100' cord, how stiff to handle and store? Think two cords would be better. May want to cover/and or elevated the connections for outside locations. Probably ok--but need to calculate voltage drop based on 100', wire size, and potential amp load.

[d23haynes57]

For a number of reasons, the cable assembly should be all in one. Conductors of that length can effectively become transformers. Having the 2 hot legs in the same cable or conduit assembly cancel the noise out. Are you thinking 2 cords plugged in end to end or 2 smaller cords in parallel? The latter is not a good idea. For the 2 cords end to tend you just need to consider not having the connectors sitting on the ground or in a puddle and that will also add some voltage drop.

That said, as the cable becomes longer there are voltage drops to consider. For voltage drop you have the wiring from the panel to the receptacle and you also have the cord on the RV itself. Your extension cord just adds to it. As you go over 50 feet wire size needs to be increased. For your 100-foot cord it probably should be 6 or 4 gauge.
Is this a onetime need or a future repeat opportunity? Maybe invest in having a proper receptacle installed where it is needed.

[Country Road]

I believe this could work on a Montana. You would have 100’ total being that the coach doesn’t have a cord, but instead a twist plug. If it has a built in cord, that’s a likely problem because of length as has been said.

The 2 @ 50’ cords would be no different than what I often use at my daughter’s home using one 50’ extension. I secure the connection with a waterproof shield.

You don’t want to buy and have to handle a 100’ RV cord. Ugh.

[jacwjames]

When I was building my house and lived in the RV for quite a while I used 2 50' cords. To protect the cord from weather I used a plastic coffee tub and cut two holes in the and put the exposed cord ends in it with the cover on. I then uses a large plastic safety cone on top of that, never had a problem with water.



I'd suggest confirming the voltage and monitoring it. Low voltage will result in higher amps on the AC's and other components.



When I first started to use my coach while building the house I had several instances where the Progressive HW50 surge protector dropped power due to low voltage. I initially thought it might be due to the temp service pole but the problem persisted BUT the surge protector did it's job.
After the house was built I plugged in Kill-a-Watt into an outlet and would monitor, sure enough I was seeing low voltage. I emailed the Coop and explained what was happening. About a week later one of their engineers called me, sure enough they had a problem at the substation, one of the taps on the transformer was set too low and they had to turn it up. He was thankful that I let them know.
Never had another problem with low voltage.

[bigb56]

This time of the year you're likely to not need nearly the power you'd need in the summer. If the heat is gas you won't have to worry about voltage drop and during the day you can open windows and run the fans or just run 1 AC if it gets too hot (looking at 75 today but only for a couple of hours). Even using space heaters at night voltage drop is not a concern (a resistive load will simply produce less power with no danger or damage).

So I am going to suggest looking into the possibility of just going with a 30 amp hookup (adapter and #10 cord) and not using the AC (or just using one if absolutely necessary, monitoring voltage of course). You certainly won't need AC to sleep at night, it starts to cool down around 4PM right now.

With 30 amps and no AC you can easily get by with a cheaper and lighter #10 supply.

I've easily survived 80F by extending the awning, opening windows and running my exhaust fans.

[glwinger]

Make sure his 50 amp outlet is for an RV and not a welder or other 220v equipment. The RV needs 2-120v circuits plus a ground and neutral. Most others do not have a neutral.

[spock12]

Why do you need 50amp for Montana. You probably don’t need 50amp as you probably wouldn’t need two air conditioners. Why not look at 30amps

[wildtoad]

Originally Posted by spock12

Why do you need 50amp for Montana. You probably don’t need 50amp as you probably wouldn’t need two air conditioners. Why not look at 30amps

He would need a 50 to 30 amp dogbone or equivalent from the 50 amp receptacle in the garage to the 30 amp extension cord(s). Then a 30 to 50 on the other end.

Not sure this would be helpful.

OP didn't state if he needed to attach the 100ft extension to a fully extended original cord so he may be looking a a total run of 125ft or more. I'd want the bigger cable.

[Sherpa Vern]

Originally Posted by edmck101

I’ve been invited to stay in a friend’s 38’ Montana in Tucson for a few weeks. To reach his garage 50A service outlet I need to buy a 100’ extension cable. I’ve used one before in my RV life and I know they’re bloody expensive. Would it be cheaper to buy two 50A cords? Just wondering if it’s okay (safe) to use two cords rather and a long 100’ cable.

I use this 6/3 with 8 ground, 50' cord extension.

https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1

At 122 feet, a 120v 50amp circuit will have a 5% (6v) drop and deliver 114v to the load.

[Carl n Susan]

I agree that the first thing to do is check that 50 amp receptacle has a RV compatible wiring (i.e. two 120v circuits plus a ground and neutral).

Two 50 amp cords will work. But using a 30 amp cord is easier and likely will support your electrical needs this winter. You can turn the water heater from electric to propane if and when you need to run one A/C.

[Solo_RV_Guy]

Originally Posted by glwinger

Make sure his 50 amp outlet is for an RV and not a welder or other 220v equipment. The RV needs 2-120v circuits plus a ground and neutral. Most others do not have a neutral.

Uh... where do you think 120/240 comes from?

The 50 amp RV outlet is *identical* in both form, shape, pinnage, and voltage as the 50 amp cooking appliance outlet in your sticks and bricks home. There is absolutely NO DIFFERENCE. There are 2 hot lines, each 120V relative to neutral and 240V line to line; one neutral and one ground.

Now... 30 amp service is a different matter. The TT30 connection (travel trailer) is 120V, with one hot line, one neutral, and one ground.

[Solo_RV_Guy]

Originally Posted by spock12

Why do you need 50amp for Montana. You probably don’t need 50amp as you probably wouldn’t need two air conditioners. Why not look at 30amps

Electric heat.


A 120/240V 50 amp service has about 12kW available, a 120V 30 amp service has 3.6kW available. Two space heaters and a microwave oven will use all of that when combined with battery charging and parasitic loads.


Making a heating mistake in Montana during winter will be very, very expensive.

[d23haynes57]

A branch circuit-receptacle for a dedicated 240-volt appliance, dryer, A/C, Air compressor, welder, some stoves, etc. do not need and most likely have the neutral. Unfortunately, some folks will cheat and use the ground wire.