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Marina Shore Power Adapters

1089 Views 3 Replies 3 Participants Last post by  jrtinwa
Just looking to have a general discussion on the use of shore power adapters in marinas. I am reviewing the electrical integrity of our marina shore power system and I am finding some interesting things. Our marina was wired before the requirement for overall 100ma GFCI protection so does not have GFCI on the main OCD or on any of the shore power connections.

Case#1 Good or Not Good?
Breaker 30A SP
Outlet 50A 125V (SS-1)
Cord 50A 125V to 30A 125V adapter to marine 10/3 shore power cord
NEC 555.19.A.3 indicates that the breaker and outlet must match but this
seems safe enough

Case#2 Good or Not Good?
Breaker 50A SP
Outlet 50A 125V (SS-1)
Cord 50A 125V to 30A 125V adapter to marine 10/3 shore power cord
The breaker and outlet match but are adapted directly to a 30 amp system
protected by a 50A breaker

Case#3 Good or Not Good?
Breaker 50A SP
Outlet 50A 125V (SS-1)
Cord 50A 125V to double 30A 125V adapter to one marine 10/3 shore
power cord
The breaker and outlet match but are adapted directly to a double 30 amp
system protected by a 50A breaker with only one 30A connection used

Case#4 Good or Not Good?
Breaker 30A SP
Outlet 30A 125V (L5-30)
Cord 30A 125V to 15A straight adapter to straight 12/3 shore power cord
The breaker and outlet match but are adapted directly to a 15A system
protected by a 30A breaker and the 15A connection if not GFCI protected
or locking style. Looks like an obvious "Not Good"
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Case 1, no good. Case 2, 3 and 4. good but lose the cord. Dennis Alwon hit it on the mark. Receptacles must be equal to (or greater than) the OCP as per Table 210.21(B)(2) & (B)(3). OCP must protect the conductors as well, so a review of what sizes are installed between the panel and the pedestal would be a good idea, as per 310.15(B)(16).
Also, flexible cord assemblies (extension cords) cannot exceed their conductor rating, as per Table 400.5 (A)(1), not the OCP supplying their outlet. Modified (field assembled) cords are generally frowned on, although I don't believe the NEC addresses this. Local codes may. There are adapters available, but you cannot adapt down (30 amp plug to 15 amp receptacle), as the 15 amp receptacle is not rated for 30 amps, and the circuit is under protected. Also, is it a #10 cord or #14?. You can adapt up if you like. Molded adapters are available for this ("dogbones, etc"). Want to plug your 50 amp cord into a 30 amp receptacle (on a 30 amp breaker) or even a 15 amp receptacle (on a 15 amp breaker), feel free. Using molded adapters is tricky though because those same manufactures also make the "adapt-down versions. Large plug end-small recept(cap) end. (50 A plug---30 A cap), which would allow just what we are trying to avoid. At least you can see this and notify the user to discontinue it's use. Probably a good idea to post some rules.
Regarding the GFP/GFCI issue. 2017 555.3 has reduced the 100 mA feeder GFP to 30 mA max. I don't know if your on that cycle, but your system is existing, so. good to think about for the future though.
 

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Discussion Starter · #4 ·
Thank you for the responses.

We have about 10 of these slips that are adapting down (50 to 30) protected by a 50A non-GFP OCD and using a 10/3 shore power cord. At this point, I am considering this both non-compliant and unsafe.

Two courses of action:
Changing the OCD to 30A and leaving the 50A outlet or
Changing the OCD and outlet to 30A?
 
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