What gauge wire do I use

[Campin_LI]

Hello,

I want to place a 30 amp breaker in the panel of my house and then run about 200 ft of uf-b cable to a 30 amp rv outlet that I will place near my travel trailer. I would like to have the ability to use my travel trailer the same way as I would if I were at a full hookup campground.

What gauge wire should I use?

Thank you!

[MEXICOWANDERER]

Complicated? For sure. There are motor start amperage complications you don't want to deal with. They'll whack you with repairs costing hundreds of dollars.

The correct answer is 6 AWG for a 30 amp rig. Violate it at your own risk. Not appropriate to place a happy face here.

[MFL]

Agree ^^^^200 ft is a long ways, plus another 30 ft of shore power cord. I did same as you want, used 75 ft of #8, plus my shore power cord. With some lights, converter/charger, and 15K AC, my voltage drops to 112 on a hot day. In your case #6 would be minimum. It is harder to work with.

Jerry

[KD4UPL]

To meet code for 30 amps #10. Nobody really calculates voltage drop on interior residential circuits because they aren't long enough for it to matter.
The NEC RECOMMENDS that you don't exceed 5% total voltage drop from the service to the end device. They also RECOMMEND no more than 3% drop in a circuit or feeder. I have a Southwire voltage drop app on my phone, I use it just about every day. For your application: 200', 30 amps, 120v you would need #4 copper to be under 3% and #6 copper to be under 5%.

[pauldub]

The NEC requires that you use 10 AWG with a 30 amp breaker. This is a safety requirement so that the wire doesn't burn up before the breaker trips. The NEC also makes recommendations on how much voltage drop one might allow and it's never more than 5%. If you are unable to know what the load really is, I guess you just have to assume that it's going to be 30 amps and go with 6 AWG wire. If you determine what the load actually is, then you can determine if 8 AWG is big enough. Either way, the wire is probably going to cost more than you would like.

[RJsfishin]

I have an RV pad at 100 feet, works great on 10 ga,.........I'd go 8 ga for 200 ft

[Campin_LI]

DFord wrote:
A search took me to: http://www.paigewire.com/pumpWireCalc.aspx where they recommended 4 AGW copper or 2 AGW aluminum for a 120 volt, 30 amp circuit at 200 ft with 3% tolerance. Change the tolerance to 5% and you can get by with 6 AGW copper wire.

http://wiresizecalculator.net/ came back with 3 AGW copper wire with a 3% tolerance or 6 AGW for 5% tolerance for direct burial.

3% of 120 = 3.7 volts - 120v - 3.7 = 116.3v
5% or 120 = 6 volts - 120v - 6 = 114v

I'd use the 5% tolerance figures.

https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=1.296&voltage=120&p... Agrees with these figures.

I just finished typing my response above and now see your. This is all to complicated for me to understand. There must be some kind of code or standard as I do not know what the load will be but I know it will be less than 30 amps since thats where my camper breaker will trip.

[Campin_LI]

Boomerweps wrote:
Wonderful calculator at calculator.net. Voltage Drop Calculator. Plug in Amperage used, distance and wire gauge and it will tell you the voltage drop in volts and percent. If you drop to 105vac, you will be on the edge of damaging electric controls in your appliances. Voltage loss will depend on actual amperage used on that length and gauge wire.
Having an Electrical Management System like a Progressive Industries one will tell you actual voltage and protect from out of spec power. Even a Kil-a-watt via a 15-30 amp adapter will let you know of power variations as you turn on different appliances.

I looked at calculators like what you described. The internet seems to complicate this subject with load calculations. My house was built having 15 amp circuits with 14 gauge wires and 20 amp circuits with 12 gauge wires. Nobody calculated any loads for each circuit - It's just standard code. I was thinking 30 amp circuit gets 10 guage but because my run is longer than 100 ft move up a size to get 8 gauge wire. The above poster mentioned 6 gauge which I also read but I also read the wire would need to be trimmed to fit in a 30 amp breaker. That's what makes me think that 6 guage is overkill. I just want to do it right. Thanks for all the input. I do appreciate it.

[Campin_LI]

GordonThree wrote:
6/3 or heavier for the future.

Thanks. I was thinking 8, thinking 6 is a bit overkill. Why 6? Does 6 fit in a 30 amp breaker?

[DFord]

A search took me to: http://www.paigewire.com/pumpWireCalc.aspx where they recommended 4 AGW copper or 2 AGW aluminum for a 120 volt, 30 amp circuit at 200 ft with 3% tolerance. Change the tolerance to 5% and you can get by with 6 AGW copper wire.

http://wiresizecalculator.net/ came back with 3 AGW copper wire with a 3% tolerance or 6 AGW for 5% tolerance for direct burial.

3% of 120 = 3.7 volts - 120v - 3.7 = 116.3v
5% or 120 = 6 volts - 120v - 6 = 114v

I'd use the 5% tolerance figures.

https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=1.296&voltage=120&p... Agrees with these figures.

[Sam_Spade]

GordonThree wrote:
6/3 or heavier for the future.

With ground.
4 total conductors.
One spare unused with the 30 amp application.

[Boomerweps]

Wonderful calculator at calculator.net. Voltage Drop Calculator. Plug in Amperage used, distance and wire gauge and it will tell you the voltage drop in volts and percent. If you drop to 105vac, you will be on the edge of damaging electric controls in your appliances. Voltage loss will depend on actual amperage used on that length and gauge wire.
Having an Electrical Management System like a Progressive Industries one will tell you actual voltage and protect from out of spec power. Even a Kil-a-watt via a 15-30 amp adapter will let you know of power variations as you turn on different appliances.

[Lwiddis]

Within reason no determent to using a larger gauge wire than the minimum.

[GordonThree]

6/3 or heavier for the future.