30a RV circuit question

[Mavarick]

Guys, I want to install a 30a Rv circuit outside the house. I was going to get this from Home Depot, http://www.homedepot.com/h_d1/N-5yc1v/R-100430208/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=30a RV circuit&storeId=10051
My question is when I have someone using it I want to make sure the breaker trips outside in this panel and not inside on the breaker in the house main panel. Instead of installing a 30a breaker in the house panel could I use a 35a or 40a breaker inside to ensure the one outside trips first? I would increase wire size to handle the larger breaker inside for safety. Or a type of time delay for the inside breaker maybe?

 

[Lou Schneider]

The purpose of a breaker is to protect wire downstream from it.  So yes, you can put a larger breaker in the house panel, as long as the wire between there and the outside box is large enough to handle the increased current rating.

This is done all the time in electrical wiring.  A panel with one or two 20 amp circuits may be fed from a 60 amp breaker in another panel.  But the wiring in between must be able to handle the full 60 amps.

The socket and RV wiring will continue to be protected at 30 amps by the breaker in the outside box.

 

[SeilerBird]

Fun

 

[COMer]

Then place where we are now does that same thing.  They provide 40A to the pole (with adequate wiring) so that if people trip something, it should be in the rig and they don't have to come down and reset their breakers.  Seems to work well.

 

[Ned]

We have two 50A outlets and the breakers in the inside panel are 60A for just that reason.  If the breakers are the same rating, the weakest one will be the one to trip, and there is no way of knowing which one that will be, inside or outside.  Follow Lou's advice.

 

[tvman44]

Sounds like a good plan.

 

[Gary RV_Wizard]

You probably won't find a 35A/120v breaker. The choice of what is available depends on the brand of the load center. I know Siemens and GE have 40A/120v, though.

 

[Mavarick]

Thanks guys, it seemed to me that using the larger breaker inside to fed the 30 outside made sense but I always like to double check. I know enough about AC wiring to know I don?t know enough about AC wiring! 
I don?t have any ?spare? breakers in the panel and I think there is a 40 available for it but will check and get whatever next size up is and size the wiring accordingly. Thank you.

 

[Lou Schneider]

Often you'll have to use larger than normal wire anyway - if you're going a long distance wire that has the ampacity to cover a 30 amp draw will lose too much voltage along the way.

So you upgrade from #10 to #8 or larger, to reduce the voltage loss along the wire.  Once you do that, there's no downside at all to installing a larger breaker in the source panel.

 

[John From Detroit]

I will support LOU's answer here,, Use bigger wire.. IN fact if I were you I'd pull the proper wire for a 50 amp circuit.. that way if you ever upgrade you are good to go. Tape off the red wire on both ends. (and label it on both ends) and use a 40 amp breaker indoors. 30 outdoors.

If you later wish to upgrade. go 50/50 and 50/50

 

[Mavarick]

Using the larger size wire makes sense as length of run/cost won't be a factor. The box will be mounted just outside the same wall the main panel is on so wire run will be short. Might as well just rate it for the 50a and be safe, think that is #6 wire? Checking tomorrow to see what breakers are available for my panel, might have to go to 50a anyways. Thanks for the suggestions.

 

[Gary RV_Wizard]

The RV 50A circuit is 240V and requires 6/3 + ground rather than the 10/2+ ground for the 30A/120v supply.

 

[ttyR2]

Read up here so you can test the finished electrical install, even if you had a certified electrician do the work: http://www.myrv.us/electric/

I've personally come across two mis-wired 30A RV pedestals in RV campgrounds so far.

 

[Gary RV_Wizard]

The powerline monitor in my coach has found more than one miswired 30A outlet for me. Typically reversed hot & neutral. One I rewired myself and another I was able to use the 30A outlet on the other side of the post (adjacent site). It's not unusual in older, smaller campgrounds that were wired or repaired by amateurs.

 

[Mavarick]

Finally was able to finish this up. Found a Cutler-Hammer 40a breaker but had to order it as no one stocked any SP breakers larger than 30a. Used #8-3 w/ground and taped off the red. Checked using the sheet above (thanks for that link) and all is good. Thanks to all for the suggestions.