Use of 50 feet of extension cord

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

BristolKing

Member
Joined
Apr 2, 2017
Posts
6
I have a travel trailer with a 30 amp 3 prong 30 foot long cord standard with the trailer. I ran a 75 foot new line inside home with a 30 amp breaker. Since I am at 105 feet just over the 10 gauge maximum of 100 feet I used 8 gauge wire instead of 10 gauge. No problem after 10 years using air and water heater together. Now I have to move trailer to cut down a bunch of trees. Was going to use a 50 foot extension but was wondering if electric seems possible to at least use air conditioning. These extension cords all seem to use 10 gauge. So in total from trailer to house I will have 80 feet of 10/2- with ground of 10 gauge and in home 75 feet of 8/2 w/ ground. Is that an ok setup? Thank you for any help.
 
If I needed (or really wanted) air conditioning in that scenario, I'd go ahead and try it. If the breaker pops, I'd have my answer. (I'm assuming there's an in-line breaker.) Power down other unneeded electrical consumers and monitor the temperature of the extension cord to make sure it isn't getting hot. AC motors don't like low voltage, but if it works for a short period while the trees are being cut down, it should be fine. My two cents

Kev
 
I'd probably plug it in and try it before actually moving the RV to see if it will work... You can take voltage and heat measurements if you wish.

Make sure the plugs and sockets are all shiny and clean - perhaps using CRC contact cleaner and lubricant to help break up any crud.
 
Monitor voltage inside the trailer with full load. . if it drops below 110 Reduce load.
You won't likely trip the breaker unless the voltage drops so low the A/C has trouble starting (This is what the better surge guards protect against the cheaper ones do not) The problem with too long an extension is voltage drop. If you are mostly charging/maintaining batteries and pre-cooling the fridge.. You will NOT have a problem.
 
  • Like
Reactions: RNS
And if you only run the one a/c (plus the onboard converter/charger to keep 12v alive), your load is more like 15-16 amps so 120 or so feet shouldn't be a problem. Just don't forget and turn on "just one more thing"!
 
Like others here, I too would try it but monitor the temperature of the cord and all of the plugged connections. In most cases, they will get too hot to hold your hand on if they are overloaded. Probably 1 air conditioner will be fine and you may be able to use both if little else is operating but be careful.
 
Not the best indicator. I will explain. The danger in a long run is not that the cord can not handle the current. it's voltage drop. So monitor the voltage inside the RV.

Now I once layed a long run of 8ga out. It had 30 amp plugs and outlets on it. We drew a fraction of that current. perhaps as little as 5-10 amps... When I went to coil it up a day later it was so hot I had to wear gloves... Till I got to the part that was in the shade and then it was COLD to the touch.

The heat was 100% Solar Energy. I've had Solar heat the Gen-Turi pipe (Generator shut down) That hot as well. Only time in fact I ever needed gloves to hold the black pipe the Generator was OFF.
 
If I needed (or really wanted) air conditioning in that scenario, I'd go ahead and try it. If the breaker pops, I'd have my answer. (I'm assuming there's an in-line breaker.) Power down other unneeded electrical consumers and monitor the temperature of the extension cord to make sure it isn't getting hot. AC motors don't like low voltage, but if it works for a short period while the trees are being cut down, it should be fine. My two cents

Kev
Thanks, Kev, for your thoughts. No in-line Breaker. Only the 30-amp breaker at the home main at front of house and your typical 30-amp receptacle at back of house. I was thinking to change that set-up and put in new receptacle with a breaker as with many Camp site hookups. Seems a lot of work to change for a couple days/maybe a week 10-day tops. 50-60 bucks for an extension seemed more logical than starting to redo electric but if necessary, so be it. Thank You kindly. It is appreciated.
 
And if you only run the one a/c (plus the onboard converter/charger to keep 12v alive), your load is more like 15-16 amps so 120 or so feet shouldn't be a problem. Just don't forget and turn on "just one more thing"!
Thank You Gary for your help. Actually, the total is more like 150 total. Consensus seems to be to give it a try and monitor the cords for overheating. But yes, i would only run the air at night after a hot day of tree cutting. Thanks for your thoughts.
 
You say the 30 amp breaker is at the front of the house and the outlet is at the rear? How long and what gauge is the wire in between? It will contribute to the voltage drop under load and needs to be considered along with what you'll lose in the extension cord.
 
You say the 30 amp breaker is at the front of the house and the outlet is at the rear? How long and what gauge is the wire in between? It will contribute to the voltage drop under load and needs to be considered along with what you'll lose in the extension cord.
He should measure the voltage at the house outlet, so he only has to estimate the voltage drop from that point on. I know its not under load and not perfect, but should be close enough for this purpose.
 
Don’t overthink it guys. At the average RV park/campground, how far away is the pedestal at the campsite, from the main service panel? Probably a lot farther away than from the main breaker box in a residence to a garage, or outbuilding.
The ‘unknown’ is the gauge of wire at campgrounds.
 
Don’t overthink it guys. At the average RV park/campground, how far away is the pedestal at the campsite, from the main service panel? Probably a lot farther away than from the main breaker box in a residence to a garage, or outbuilding.
The ‘unknown’ is the gauge of wire at campgrounds.

Good point and again I say MEASURE THE VOLTAGE INSIDE THE RV when it's under load.
That takes in the entire path from the Transformer to the RV and back.
In fact always keep a voltage monitor in line.. Alas my favorite is no longer made but a Kill-a-Watt in Volt meter mode.. That works too.

Camping world link I have one around here somewhere but use a Kill-a-watt and an MFJ (MFJ no longer made)
 

Latest posts

Members online

Forum statistics

Threads
132,759
Posts
1,400,369
Members
138,388
Latest member
Nedh
Back
Top Bottom