How Long is Safe for an RV Power Extension Cord

BB_TX wrote:
Depends a lot also on what voltage you have to start with. Lot of difference if the park has 125 vac or 110 vac at the pedestal. Or somewhere in between.

This is most important. At a full 30 amps, you'll get 5% drop over 100 feet of #10. If the pedestal is at 115V, you end up with about 109V at your panel. Then you'll drop another 0.5-0.7% on the branch circuit to your A/C.

Chris Bryant wrote:

MFL wrote:


Cute, and good catch! But did either of you have the answer to the question?

Yeah- it's been answered- over and over, with examples. As long as the voltage stays OK, it is fine.

brilliant

MFL wrote:


Cute, and good catch! But did either of you have the answer to the question?

Yeah- it's been answered- over and over, with examples. As long as the voltage stays OK, it is fine.

Chris Bryant wrote:

Sprink-Fitter wrote:


Chord, the question is about electricity, not music.

I was composing a reply to this, but I could not figure whether this is a major or minor problem. In the interest of harmony, I'll point out it always depends on the conductor.

Cute, and good catch! But did either of you have the answer to the question?

It's OK, the forum has been slow.

Jerry

Sprink-Fitter wrote:


Chord, the question is about electricity, not music.

I was composing a reply to this, but I could not figure whether this is a major or minor problem. In the interest of harmony, I'll point out it always depends on the conductor.

MFL wrote:

Water-Bug wrote:
I know that the answer depends on the current draw of the RV, but am wondering if it would be safe to run the AC on a 100 ft 30 amp cable. The answer is probable to turn on the AC and measure the voltage drop at a plug, but buying a 75 foot cord just to find out could be an expensive experiment.

I think 30 amp RV chord uses 10 awg wire. At 100', you should have about 5 percent drop. So if you have 120+ at the pedestal, you should be fine, with nice clean connections between chords, and at post.

Jerry

Chord, the question is about electricity, not music.

traveylin wrote:
For long distance power 100 feet 10-15 amp, enough for ac or microwave plus various battery chargers, I will use a heavy duty extension #12 cord which is enough on not hot days. The limit I found was the plugs which tended to get hot and soft, Plugs can be upgraded. A hundred foot rated 30 amp cord would be a beast to carry,

A beast to carry is right!

Try it with 12 gage - and check the voltage drop/s before you spring big bucks for 100' of 30 amp cord!

~

I was parked on a ranch for 4 years, where the well house is about 300' from the main house and electric meter, fed with a 30 amp circuit breaker and #8 wire. I could count on a voltage drop of about 1 volt per amp that I was consuming.

So a 12 amp load such as the microwave would drop the voltage from 120 volts to about 108. I have a voltage booster, so I can bring it back up by 12 volts, and run the A/C. Before voltage is 132 volts, once the A/C is running then it drops to around 118 - 120 volts.

One time I was parked at a drag race, and I was plugged into a 20 amp receptacle, then had a 50' long #14 cord, then a 25' long #12 gauge cord, and then 50' #10 cord, the 12 volt voltage booster, then the 25' long RV power cord. I had about 113 volts at the kitchen sink receptacle while the A/C was running. It was warm - 85 - 90 and humid too!

So with a voltage booster, you can run a longer cord, and make up for it with the voltage booster!

Fred.

I've run my AC on 125' of #12 cord plus the camper's aprox. 30' of #10 cord. I don't remember the voltage at the RV but it was around 110 I think. Everything worked fine. I don't see how you could have a problem with 100' of #10 unless you try to run the AC, microwave, toaster, etc. all at the same time.
My voltage drop calculator says that with 125' of #10 at 30 amps starting with 120v you would loose 7.9 in the run. Not really desirable but shouldn't hurt anything.

Water-Bug wrote:
I know that the answer depends on the current draw of the RV, but am wondering if it would be safe to run the AC on a 100 ft 30 amp cable. The answer is probable to turn on the AC and measure the voltage drop at a plug, but buying a 75 foot cord just to find out could be an expensive experiment.

I think 30 amp RV chord uses 10 awg wire. At 100', you should have about 5 percent drop. So if you have 120+ at the pedestal, you should be fine, with nice clean connections between chords, and at post.

Jerry