How to use two 30 amp receptacles and get 50 amps

[Volta]

Not moot. If it isn't justified because of the NEC, then the NEC doesn't end at the receptacle.

And we can't argue that just because the plug doesn't fit the outlet that someone won't build some type of adapter to make it work.

Not in this thread. :roll:

 

[iwire]

On the EGC(s)???

If this 'box' combines the neutrals you will have odd current flow on the neutrals, if this box only uses one of the neutrals the path back to the other trans would be on the EGCs. But Don did point out that most marine pedestals will be supplied from one source.

 

[Smart $]

If this 'box' combines the neutrals you will have odd current flow on the neutrals, if this box only uses one of the neutrals the path back to the other trans would be on the EGCs. But Don did point out that most marine pedestals will be supplied from one source.

If the device used only one neutral, which I doubt, the current would "mostly" go through the GECs common to the transformers, but yes there could be some through anything bonded between systems, but would likely be minimal on the shore power egcs. All the more reason it likely uses both neutrals.

 

[lakee911]

Are these receptacles not GFCI protected? If they were, this device wouldn't work. If they weren't, that seems silly in the close proximity of water, no?

 

[don_resqcapt19]

And yet there they are, some of them for many code cycles. It seems like a precedent has been set even if we do not really like it.

Probably only because they have never been challenged in a court of law. They probably never will be as the cost to challenge would far outweigh the gain. Some of the members of CMP10 are on record as stating the code does not apply beyond the receptacle, but I don't think they have said that in a formal panel statement that has been adopted by a majority of the panel, and that does not help a lot because Article 422 belongs to CMP17

 

[don_resqcapt19]

Are these receptacles not GFCI protected? If they were, this device wouldn't work. If they weren't, that seems silly in the close proximity of water, no?

Shore power receptacles for boats at a marina are not required to be GFCI protected.

 

[dbuckley]

If the device used only one neutral, which I doubt, the current would "mostly" go through the GECs common to the transformers, but yes there could be some through anything bonded between systems, but would likely be minimal on the shore power egcs. All the more reason it likely uses both neutrals.

These things will be used other for their intended purpose, and in these cases the two 125V sockets may well be on seperate panels, or services, or transformers, so bad stuff will happen.

In my opinion the legitimacy of these devices is not determined by the NEC (which simply does not envisage this class of device), or the listing, but by the question of what are the risks associated with using these things?

 

[Smart $]

These things will be used other for their intended purpose, and in these cases the two 125V sockets may well be on seperate panels, or services, or transformers, so bad stuff will happen.

In my opinion the legitimacy of these devices is not determined by the NEC (which simply does not envisage this class of device), or the listing, but by the question of what are the risks associated with using these things?

A proper evaluation is warranted. Theoretically, there will be occurences where objectionable current will be placed on grounding conductors and non-current-carrying metal parts. Without a proper evaluation, or well documented cases of "bad stuff", claims of risk are just speculation.

FWIW, the Hubbell item brought up by the OP is small potatoes in this market niche. This link takes you to Google product search results using the term "shore power Y adapter". Note that because of the search term, many of the results will be "splitters" rather than "combiners". The big name in "combiners" seems to be Charles.

 

[K8MHZ]

Here it is from the aforementioned inspector:

What do I think. I think this device gives me heartburn. As for whether it is regulated by the NEC, I doubt it. while I don't necessarily agree that the NEC stops at the outlet, It does appear to be outside the scope of the NEC. I would refer you to

NFPA 70-2008 (NEC) Article 90.2(B) This Code does not cover the following:
(1) Installations in ships, watercraft other than floating buildings, railroad rolling stock, aircraft, or automotive
vehicles other than mobile homes and recreational vehicles.
Ships and boats are regulated by title 46, Code of Federal Regulations. That will give the coast guard something to
do as federal regulations are beyond the scope of my authority.

So the short answer is that I would not cite it .

This particular inspector is known as the most strict in the area, perhaps the state, and has been a mentor for me since I started the apprenticeship. I trust his take on this and it seems he has taught me well.

I would also like to add that this particular inspector is the one I learned the adage that, if you follow the NEC to the letter, you are the worst electrician allowed by law. For some reason, that did not go over well here.

I stand my ground that although the device makes me cringe, there is no jurisdictional basis to prevent it's use.

Let's also consider the fact that it may be a very safe and useful device. Without knowing what is inside the little yellow box and how it works, none of us can know for sure that it is not.

 

[Dave58er]

.....if you follow the NEC to the letter, you are the worst electrician allowed by law.

:grin: I get it! :grin:

Bare minimum baby!

 

[hardworkingstiff]

The 2 biggest issues I have with this device is that it is easy to overload the 30-amp receptacles and there is not a common trip/handle on the breakers.

The parallel neutrals will only be from the outlets down to the busbar of the pedestal, and they recombine there on one conductor back to the panel. Not a big deal in my opinion (although a NEC violation).

 

[LarryFine]

... it is easy to overload the 30-amp receptacles ...

Wouldn't the two 30a breakers still be there?

 

[hardworkingstiff]

Wouldn't the two 30a breakers still be there?

Actually, I meant to say breakers not receptacles.