Extension cord max length

[StreaminGeo]

How long of an extension cord can I use to power my 30 amp 25-foot 2004 Safari? As it is now I run a 50-foot 12 gauge cord to it with no problem.

[rmkrum]

The 12 gauge cord is only good for about 20 amps absolute maximum draw. You can run your convertor to power 12 volt stuff, like lights and fans, but you risk damage if you try to run your air conditioning. It's also easily able to keep batteries charged.

[OTRA15]

Originally Posted by rmkrum

The 12 gauge cord is only good for about 20 amps absolute maximum draw. You can run your convertor to power 12 volt stuff, like lights and fans, but you risk damage if you try to run your air conditioning. It's also easily able to keep batteries charged.

In this case, the 50' #12 cord should also come out of a 20 amp outlet, which is in turn wired with a #12 or heavier gauge wire inside the house/garage/shop IMO. From where the electrical service comes in near the electric meter, one must consider the entire distance from the circuit breaker panel to the Airstream, in order to ascertain proper AWG and amperages.

The normal 30 amp shore power cord from the AS must be taken out of service also, or its length and AWG figured into the overall calculation.

We limit our 50' #12 extension cord to 15 amps, which covers the converter/charger, the fridge, and a small fan to circulate the air inside. No water heater or A/C on the 120. We have a very short Furrion 15 amp shore power cord which connects to the trailer's twist fitting.

https://www.amazon.com/Furrion-FP301...to+15+amp+male

StreaminGeo, have you ever tried to run your A/C on this #12 cord, while other 120-volt uses are on? It should trip your circuit breaker at the house/shop/garage immediately IMO. If not you might want to have an electrician check things out, and also turn the A/C off -- right away.

Good luck,

Peter

Originally Posted by StreaminGeo

How long of an extension cord can I use to power my 30 amp 25-foot 2004 Safari? As it is now I run a 50-foot 12 gauge cord to it with no problem.

[ijustlee]

It depends on what you expect to power. Also are you using a 30 amp RV plug or a 15 amp household plug with an adapter? Anything over 10 amps starts heating up a standard household plug. You can probably run your AC or a microwave or a heater one at a time on a 100' 12 gauge cord. You can go longer if you just run the converter/charger. Keep a plug in volt meter in sight in the trailer and watch out for voltage drop. If I need to go longer than 100 feet I use #10 or even bigger wire. I once used 350 feet of #6 wire so I could be down by a creek and use the AC and the microwave.

[wcrockett]

Originally Posted by StreaminGeo

How long of an extension cord can I use to power my 30 amp 25-foot 2004 Safari? As it is now I run a 50-foot 12 gauge cord to it with no problem.

I made a 125' cable using romax 8/2 for a 30 Amp. We connected it to a 2005 31' AS using their standard 25' cord.

[Rgentum]

When I ran power to my AS barn (see photo), I used a 30 amp breaker in the house breaker box & from it ran #6 copper stranded 50 ft through the house floor joists & then another 100 ft from the house undergrounded to a breaker box by the side of the AS (in photo, covered by a black nylon sack, to the right of the golden flower pot). The box has a 30 amp breaker & a 30 amp socket, to which I attach the std 30 amp cord from the AS. So far, I haven't had any problem running the AC.

[StreaminGeo]

Thanks for the answers. I've rarely run the AC off of this cord (plus the 20 AS cord) with no apparent problem. Usually the trailer is just plugged into the house to keep things going (fridge, lights if I'm out there at night) while the AS rests in the side yard. What kind of damage should I expect if I do this often? The breaker hasn't tripped yet -- except if I try to run the house washer or dryer that are on the same circuit.
The house is ancient and I'm in the process of getting the whole thing rewired (if the electrician will ever call me back....). This is giving me a lot of good info as to what kind of setup I'll eventually want.

[rvb]

I have a Progressive Industries surge protector with the digital readout which lets me see my electrical voltage and amps. My heat pump draws 17amps starting and runs at about 13.5 to 14amps. When I hook up to a pedestal I check the voltage. If it is low, the wire runs are too long or undersized.

I have run it from a dedicated 20A outlet before I wired a 30A at home with no problems. At the family farm I hooked up to the 20A on the porch and had low voltage and found out that half of the living room was on that circuit when the fuse blew.

For on the road, I made a 6' 30A cord with #10 wire for those times when the pedestal is just a little too far away and carry a 25' 30A cord with #8 wire if I have to go 45' to shore power.

[PharmGeek]

I have a sort of standard orange extension cord bought at HD that is pretty long...I want to say it is 50 feet...I plug into a progressive industries external surge protector unit...ive been using that cord for a while now, seems to be working fine to keep batteries fresh, to sometimes crank up the fridge in prep for a trip....ive even ran a dehumidifier for an extended period without any apparent problems...wonder how many amps I am drawing with all of those going?! Would the progressive industries unit shut off or would that risk heating up the extension cord itself if you overdo it?

[MelGoddard]

Originally Posted by StreaminGeo

How long of an extension cord can I use to power my 30 amp 25-foot 2004 Safari? As it is now I run a 50-foot 12 gauge cord to it with no problem.

If you're just using it to power the converter for 12V. and maybe the fridge, you should be OK. You will probably have some voltage drop over that distance, especially with the fridge on.
Any other draw over that distance calls for at least a 10 gauge, and preferably 8 gauge if using the AC. and other high draw items, to avoid excessive voltage drop.

One thing to avoid, is to 'loop' your run of wire, to avoid possible overheating of the cord due to magnetic induction. (it's a 'coil' right?)

[gator.bigfoot]

There isn't any rules on the length of extension cords that I'm aware of, but the longer the run the higher the resistance of the wire and with a high current load that equals heat. Most extension cords are of poor quality so they will cause additional issues due to resistance. Also the longer the run the greater the voltage drop. So if you are starting out with 110 volts at the plug end and you have enough of a voltage drop due to resistance you might be down to 100 volts coupled with a high current draw of the AC. This in turn causes you're compressor to overheat causing it to fail prematurely. Also the lower voltage causes a higher current draw since your load doesn't change until the AC cycles on and off.

Most home breakers will allow some overloading, but after a while they will trip. The Square D breaker will trip faster than the rest due to its patented trip mechanism and will warn you of an issue. As for an old house it most likely uses fuses which in most cases has already been replaced with a larger fuse making it a fire hazard. Which may explain why it hasn't tripped.

[Kevin245]

Originally Posted by StreaminGeo

How long of an extension cord can I use to power my 30 amp 25-foot 2004 Safari? As it is now I run a 50-foot 12 gauge cord to it with no problem.

Anytime you increase the line length on a given conductor you will experience voltage drop. Small voltage drops in the 2 to 3 percent range are usually considered acceptable. The thing is your appliances, AC, etc. may run on lower voltages but usually there is a price to pay in the form of reduced performance and service life.

Here's an old post with the formulas:

http://www.airforums.com/forums/f37/...tml#post702381

Or an online calculator you can fiddle with:
http://www.engineersedge.com/instrum...ator_12928.htm

[AWCHIEF]

Some interesting info here,

http://www.mikesenese.com/DOIT/2011/...-for-my-tools/

[james.mileur]

Originally Posted by gator.bigfoot

. As for an old house it most likely uses fuses which in most cases has already been replaced with a larger fuse making it a fire hazard. Which may explain why it hasn't tripped.

If that old house has round glass fuses, have you checked for pennies behind the fuses? If so, your fire hazard has become a ticking fire bomb. If pennies found, be careful to kill all power to the fuse box before removal.

[Mollysdad]

If I was going to run more than 50' I'd pull wire through a buried conduit to a outlet box from your breaker panel rather than rely on a extension cord. Then you can use larger cable. Extension cords that are large gauge get too expensive anyway.

[Sharon_Jon]

Thanks for the preceding well thought out suggestions. Assuming that the garage plug is on a 15 amp breaker and the extension cord is the proper size and length does the picture below show and appropriate connector between the extension cord and the trailer? Thanks for your help.

[OTRA15]

Originally Posted by Sharon_Jon

Thanks for the preceding well thought out suggestions. Assuming that the garage plug is on a 15 amp breaker and the extension cord is the proper size and length does the picture below show and appropriate connector between the extension cord and the trailer? Thanks for your help.

The Furrion shore power cord linked [via Amazon] at the bottom of Post #3 is the same mfg. as the AS shore power port. Not sure your yellow connector has the correct threaded connection to make up with the AS?

[MelGoddard]

Originally Posted by OTRA15

The Furrion shore power cord linked [via Amazon] at the bottom of Post #3 is the same mfg. as the AS shore power port. Not sure your yellow connector has the correct threaded connection to make up with the AS?

My AS came with one, and it's in constant use.
I have the fridge on at the moment, preparing for an outing, and using a 12 ga. 50' cord from the house. Just checked............
All the plugs and cord are cool.

[MelGoddard]

And Speaking of power cords and such;
There are times when you may run into a "Hot Skin Condition", due to bad grounds somewhere in the system.
The question is; is it your trailer at fault? Or the wiring at the pedestal?

Mike Sokol who writes for "RV Travel.com" is an electrical engineer, and last weekend,s issue had a tip from him to prove out your rig's grounding performance.

You take a simple trouble light, (a handle with a light bulb inside, a sharp point at one end, and a wire with an alligator clip at the other.)
Make sure that your shore power cord is disconnected, from the tower.
Put the clip on the positive pole of the batterys.
Take your power cord, still attached to the trailer, and touch the point to the ground pin of your plug.
The light bulb should glow brightly indicating a good continuity of the ground.
This eliminates your rig as being at fault; and you can go after the campground's owner.
If the bulb glows dimly or not at all; start searching your wiring for the 'open'.

I tried it on my FC, and both cords, and my homemade extension, were good.