400 SB- 30amp-to 50amp

The interesting thing I see on Marinco's web site is that most of the power cords have the UL CSA symbol displayed on the product page. None of the pigtail or Y adapters do. Wonder if this is an oversite on the web design, or more likey they can't get UL CSA approval for the adapters. Hmmmm sould be interesting to see it they reply to Franks email.
 
I'm trying to understand that as well. Electrical isn't my strong suit...
Just because there's 50 amps available doesn't mean the boat can actually try to draw 50 amps through a cord only rated for 30- the main 30 amp breaker at the panel would trip.

Right?

Asked and answered. What if there's a fault in the wiring inside the boat between the inlet and the breaker panel? Not a dead short that would kick out the 50A breaker, but enough to draw 35 to 45 amps. The 50 wouldn't trip but that 10 gauge wire, which is only OK for 30 A, would sure get hot.
 
temp_wiring01.jpg

Union electricians.. :smt009
 
asked and answered. What if there's a fault in the wiring inside the boat between the inlet and the breaker panel? Not a dead short that would kick out the 50a breaker, but enough to draw 35 to 45 amps. The 50 wouldn't trip but that 10 gauge wire, which is only ok for 30 a, would sure get hot.

10-4.
 
Dom has the right solution. The breaker at the source must be appropriate to the wiring that runs from the breaker to the load.. You can look up the values, but off the top of my head
14 ga wire - 15A
12 ga wire - 20A
10 ga wire - 30A
8 ga wire - 50A

If the wire is thinner than shown above, it's probably not spec. Also, those figures are for wires that are not bundled into a thick cable or run in a sealed conduit. You have to de-rate for that.

I sent an email to Marinco yesterday. Asked if it was safe to use a 50A to 30A adapter when there would be a 50A breaker protecting 30 feet of 10 gauge wire outside the boat and 20 feet of 10 gauge wire inside, which seemed to me to violation the National Electric Code of NFPA. So far, no response from them. Probably legal is sweating it right now. I do not expect to ever hear from them about this, but I'll try again tomorrow. Maybe they already have a Domadapter on the drawing boards right now.

Best regards,
Frank

Any word back from Marinco yet?
 
NOPE. First post states that he wants to connect 30A power cord to 50A outlet, so where is a problem? His boat amperage draw should never exceed pole's outlet limits. Or I am reading something wrong?

Read you own edited by me post...and if it does exceed? Even that being said, you are still only protecting a 30 amp device (shore power cord and boat up to main panel on boat) with a 50 amp breaker.
 
If you are correct then that would be a 25A 240V service and this entire debate is moot.

If we are indeed talking about a 25A 240V service, with a 3 Pole, 4 wire connector, consider the following:

As stated above the splitter separates the 2 hot legs (one for each outlet), and the ground and neutral are common
50A Socket: (L1 - L2 - N - G)
Outlet 1: (L1 - N - G)
Outlet 2: (L2 - N - G)

In the adapter, the second hot leg is not used
50A Socket: (L1 - L2 - N - G)
Outlet 1: (L1 - N - G)
L2 is unused!

So, this means that the maximum power available at the 30A outlet would be 25A.


That said, I suspect your marina has installed 25A breakers with a 50A connector, likely as a cost saving measure in construction (25A breakers and wire are cheaper) and to limit the amount of power drawn by a single vessel. (figure they don't want you running all your appliances all the time on their dime)

So, in the case of 25A breakers, both the adapters and splitter would both be considered "safe", however being that it is a 50A connector being used, it is possible that the OP may be in a marina that has 50A breakers installed, which would then make both "unsafe".
I'll take a closer look at those breakers when next at the boat
 
Any word back from Marinco yet?

No. Just checked my email. Now I'm sure that someone in mangmement and maybe even legal threw a fit. They'll never answer because there is no right answer. If they say it's OK, when it's a clear NFPA NEC 70 code violation, then they open themselves to all kinds of legal problems if an electrical fire results. If they say it's not OK, then why are they selling them? Finally, there is the last possibility, that it's OK and not a code violation, in which case, why not send a response saying it is not a code violation because of XYZ?

Be on the watch for a DomAdapter with built-in 30A circuit breakers to be put on the market really soon now.

Best regards,
Frank C
 
I am on record as wanting a copy of the book and an adapter as well. Just wondering since the book was promised to us "first part of may" or something close to that, we should start a new poll......Which product hits the market first?
 

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