I know it's not to code...

[ForceFed70]

But will it be safe?

I ran 10/3 wire with a 30A single pole breaker to my RV plug.

The plan for now is to have a single phase 30A RV plug and not use one of the conductors.

However, I ran 3 conductors and used a 2-gange box so if at some point I want to upgrade to a 50A style plug I can. At that time, I would still use a 30A (10ga wire) breaker but would switch to a 2-pole breaker and use the spare conductor.

I know code says you can't do this. A 50A plug must have a 50A breaker and suitably sized conductors.

But, I really don't see using a 50A plug anytime soon if ever, and if I do I'm thinking I could squeek by with only 30A.

So long as I'm not tripping the breaker, this should be a safe setup should it not? If it turns out that I do need to use the 50A style plug often, I will upgrade at that time. I'm more thinking along the lines of friends/family showing up with a big RV or something which wouldn't happen very often.

 

[trainer]

Shouldn't be a problem since you'll be limited to drawing 30 amps through a device (the recepticle) that is designed for up to 50.

Does the code really say you cant do this?

 

[ishiboo]

As long as you retain the 30A breaker on the 10-3 you'll be fine. You could "safely" even upsize it temporarily if you had to run a welder or similar device on it.

 

[tfi racing]

Shouldn't be a problem since you'll be limited to drawing 30 amps through a device (the recepticle) that is designed for up to 50.

Does the code really say you cant do this?

The only way a receptacle can limit the amount of current is by melting and burning up,the function of the breaker is to protect the wire and receptacle.

CEC 26-700(2) does say you can't do this,I only looked it up because I thought as well installing a larger receptacle than the circuit wouldn't really matter,I guess the intent of the rule is to avoid nuisance tripping and a temptation to put a larger breaker on that conductor.

 

[mrb]

install a 14-30 receptacle. that way your installation is code. Then use a 14-30 male to 14-50 female adapter to plug your RV in

 

[NitroPress]

I'd guess that code forbids it because someone, some time, might plug in a 50A piece of equipment using the matching plug, and cause some unspecified problem. Code generally makes sense, if sometimes in fairly thinly reasoned ways.

But I don't think you're creating any hazard by using a higher-rated socket for lower current use.

 

[ForceFed70]

install a 14-30 receptacle. that way your installation is code. Then use a 14-30 male to 14-50 female adapter to plug your RV in

That's a good idea! Think that's what I will do when the time comes.