[Kcrosby19]

I have a rv that is 125V/30 amp. We have 10 wire ran 189 feet ran to our breaker box with a double post 30 amp breaker. I can run the A/C but anytime I go to turn the hot water heater on or use the microwave the air conditioner “bogs” down. Do I need to run #8 size wire or #6? And should I use copper or aluminum

 

[roughneck]

What do you mean you have a double breaker? Should only have a single, your supply is only 120V.
What’s the voltage at the outlet?
A 50A RV outlet has a double pole breaker, with 2 hots, a common and ground.
I believe that should have been #8 or #6.

 

[Oldmaster]

Yeh, sounds like you're a victim of voltage drop.

 

[Oldmaster]

30 amp at 190 ft using 10 wire has a voltage drop of 9.5 percent. The lower the voltage the higher the amperage.

 

[Kcrosby19]

I mean I have a double pole 30 amp breaker but Only running a single hot from it. Should I switch to a single pole breaker with #6 wire?

 

[roughneck]

It should be a single breaker.
And yes, you’ll need to increase wire size.

 

[Kcrosby19]

So what would the voltage drop be at 190 ft with #6?

 

[Kcrosby19]

Should I use aluminum or copper? I was thinking copper since it’s a better conductor and I’m running a long distance

 

[roughneck]

Are you running #10 aluminum right now?

 

[Kcrosby19]

I’m running #10 copper right now

 

[roughneck]

Stick with copper. Aluminum isn’t as conductive.

 

[Oldmaster]

Voltage drop with #6 would be 3.75 percent. Much better

 

[Oldmaster]

#8 may work depending on the load. #8 at 20 amp is 3.75 percent.

 

[dmxtothemax]

Always with the size of cable vs voltage drop,
The bigger the cable the less is the drop.
So use the biggest cable you an afford,
And make sure it will physically fit all your connectors.
so if #8 will just do it, then #6 would be even better,
but of course it will cost more and be physically larger.

 

[CodeMatters]

If lugs on both ends are rated for it, I'd consider #6 Aluminum.
Will give same conductivity as #8Cu at much lower cost.

 

[Kevin_Essiambre]

If lugs on both ends are rated for it, I'd consider #6 Aluminum.
Will give same conductivity as #8Cu at much lower cost.

I second this option.

#6 aluminium should fit the breaker within issues, and the receptacle with no issues (a 30-TT receptacle should accept #6 with no issues).

Aluminium will be somewhere around 2/3rd the price of copper.

Sent from my new phone. Autocorrect may have changed stuff.

 

[Oldmaster]

Aluminum will give you 5.62 percent voltage drop. I'm not sure if it will fit on a 30 amp receptacle.

 

[Oldmaster]

Right now #8 copper is .41/ ft. 6 aluminum is .26/ ft.

 

[NCmountainCabin]

... I'm not sure if it will fit on a 30 amp receptacle.

yes, agreed, this is one of the 'issues' with trying to use a much larger size gauge wire than what a typical 30amp RV outlet is designed to use - the aggravation and sweat trying to 'push' this much larger wire into the 'tiny' holes on the back of the 30amp outlet is the problem... and can lead you to insanity.

I've experienced this on 50amp outlet's as well, if you attempt to use 6 gauge wire - and that's with a much larger diameter wire hole for this outlet.

What you might want to do is install a 240v 4-wire 8 gauge 50amp outlet, by using a 30amp to 50amp adapter from your RV - you can use a 30amp double pole breaker, if you wish, since you are not going to ever be 'using' 50amps per side, only 30amps max on only ONE side.

 

[Kevin_Essiambre]

yes, agreed, this is one of the 'issues' with trying to use a much larger size gauge wire than what a typical 30amp RV outlet is designed to use - the aggravation and sweat trying to 'push' this much larger wire into the 'tiny' holes on the back of the 30amp outlet is the problem... and can lead you to insanity.



I've experienced this on 50amp outlet's as well, if you attempt to use 6 gauge wire - and that's with a much larger diameter wire hole for this outlet.



What you might want to do is install a 240v 4-wire 8 gauge 50amp outlet, by using a 30amp to 50amp adapter from your RV - you can use a 30amp double pole breaker, if you wish, since you are not going to ever be 'using' 50amps per side, only 30amps max on only ONE side.

Aluminum will give you 5.62 percent voltage drop. I'm not sure if it will fit on a 30 amp receptacle.

The leviton RV receptacle will accept up to #4... I would not advise trying to use #4, as it will be a royal PITA.

If you do run #6... MAKE SURE YOU USE A LARGE BOX! take my word on it, a small box is the enemy here.

I have used this exact receptacle with #6 for a client.

Sent from my new phone. Autocorrect may have changed stuff.