50 amp rv plug into 30 amp receptacle

[Gary RV_Wizard]

Oh, I know folks do it, and I know "it works", but it is not safe, nor is it legal.

It's not "illegal" unless hardwired that way. You can plug in any size or type of portable equipment downstream from the outlet. You do it all the time at home, e.g. plug an 18 or 16 gauge power cord into a 15A-rated outlet on a 15A-protected circuit. For example, a table lamp or a crock pot. It is not required to use only 14 gauge extensions in 15A outlets.

Admittedly this is less than perfect from a safety viewpoint, but the electrical code has to be practical too.

 

[Bob K4TAX]

It is my strong belief that anytime one exceeds the published and stated rating of a piece of electrical equipment, one becomes a very underpaid and unqualified test engineer. ( I could explain it differently but many might not like the language. ) What happened to common sense? The manufacturers publish those specifications for a reason. Read them, believe them, and follow them.

Bob

 

[Ex-Calif]

HOWEVER, if using the 50 amp power post outlet with a Y cable shown in #7 and #35 above, I then am concerned that the 30 amp hardware, namely the female outlets on the Y, the male plugs into the outlets, and the #10 ga. wire to the RV is rated at 30 amps, but they are protected by a 50 amp breaker in the power post. This does not comply with the NEC (National Electrical Code) I view it as an unsafe application. Yes, I realize the RV has a 30 amp breaker inside to protect the system internally, but what about externally? The components are 30 amp rated but protected by 50 amp breakers. Not OK.

Oh, I know folks do it, and I know "it works", but it is not safe, nor is it legal.

Glad you said it and it's a valid concern. I think there are levels of "safety" - I just replaced the Walmart $10 50 to 30 amp adapter at my pedestal post. The 30 amp female plug hot socket was getting burned up over about 8 months of continuous use.

Was it unsafe in terms of people dying? Not in my estimation. Was it unsafe that it could cause a "major" fire? Not in my estimation. Could it damage or fry some equipment - Pretty much yes if left unattended.

So if one draws 50 amps through one leg of the 30 amp splitter above they are definitely above the ratings for the hardware.

I think it's important to note but the OP is stating he really only wants to run the chargers on 2 units to keep the RVs alive. I think that's OK but there is no way I would intend to run two liveaboard RVs that way nor recommend anyone else do so.

 

[Bob K4TAX]

It's not "illegal" unless hardwired that way. You can plug in any size or type of portable equipment downstream from the outlet. You do it all the time at home, e.g. plug an 18 or 16 gauge power cord into a 15A-rated outlet on a 15A-protected circuit. For example, a table lamp or a crock pot. It is not required to use only 14 gauge extensions in 15A outlets.

Admittedly this is less than perfect from a safety viewpoint, but the electrical code has to be practical too.

I stand corrected on the legality of the use of portable equipment. Thanks Gary.

 

[Martian]

Boy, this sure went off the rails!

 

[Kirk]

This does not comply with the NEC (National Electrical Code) I view it as an unsafe application. Yes, I realize the RV has a 30 amp breaker inside to protect the system internally, but what about externally? The components are 30 amp rated but protected by 50 amp breakers. Not OK.

I would be very surprised if the National Fire Protection Association would approve of the existance of that adapter, or any of several others that are available. It is a committee of the NFPA that develops the NEC and then many states and cities adopt it. We live in TX and very few counties have adopted the NEC and they do not have inspectors for it. What is key here is that the RV industry is not subject to those rules and they often violate parts of that code.

What happened to common sense? The manufacturers publish those specifications for a reason. Read them, believe them, and follow them.

I very much agree with you. Today we visited an RV show for the first time in years and I saw one of the splitters in a vendor both at the show and took a look at it. I was connected such that each of the 30a plugs was on a different leg of the 50a outlet. It also came with a number of warnings in the operator instructions that caution not to connect anything that is rated to draw more than 30a to the plugs. Lots of legal disclaimers, most likely intended to protect the manufacturer from suit for buyer choosing to misuse it.

 

[Bob K4TAX]

I would be very surprised if the National Fire Protection Association would approve of the existance of that adapter, or any of several others that are available. It is a committee of the NFPA that develops the NEC and then many states and cities adopt it. We live in TX and very few counties have adopted the NEC and they do not have inspectors for it. What is key here is that the RV industry is not subject to those rules and they often violate parts of that code.

I very much agree with you. Today we visited an RV show for the first time in years and I saw one of the splitters in a vendor both at the show and took a look at it. I was connected such that each of the 30a plugs was on a different leg of the 50a outlet. It also came with a number of warnings in the operator instructions that caution not to connect anything that is rated to draw more than 30a to the plugs. Lots of legal disclaimers, most likely intended to protect the manufacturer from suit for buyer choosing to misuse it.

My point, there are several devices that are rated at 30 amps and are downstream protected by a 50 amp breaker. It is a moot point until an accident happens and there is a loss of life or property.

 

[Tom]

Time to wrap this up. The OP received his answer to the original question.

 

[Gary RV_Wizard]

What is key here is that the RV industry is not subject to those rules and they often violate parts of that code.

I think that's a bit of an overstatement. The RVIA has adopted the relevant parts of the gas, fire and electric codes via NFPA 1192 as part of their ANSI standard and all RVIA members agree to adhere to the standards (and apply the RVIA medallion as proof). To the best of my knowledge, all states have adopted the RVIA RV standards as well, i.e. new RVs sold in the state must meet RVIA standards.

Edit: RVs are not subject to the same building codes as site built homes or manufactured homes. It has been pointed out to me that few states specifically adopt the RVIA standard or NFPA 1192. Rather, they accept the RVIA medallion/certification as evidence the RV meets all applicable codes and safety standards.