Mike Dolt Enterprises
Mike Dolt Enterprises
User: Free Electron, Location: Upstate New York
Asked on: Friday, April 22, 2011 at 9:29 am EDT
Answered on: Tuesday, May 14, 2024 at 4:32 am EDT
Question: There's not a lot of info out there on dock wiring. I'm reaching out to you guys for some assistance.We are working with an engineer to wire a dock . They know their design needs to be improved. so please don't beat them up too bad. Plans have called for a pedestal mounted 400a , 208/120v ,3 phase service on shore. Then feed the dock with a GFI three phase breaker to the first pedestal with feed through lugs to the next pedestal. Pedestals have two 50a and four 30a single phase twist locks receptacles each for a total of two pedestals with further expansion of four more. Slips are 40 and 30 foot long. So here are my Q's.Most boats that are 20 to 40 long are wired 240volt single phase, can they be fed with 208 single phase?I don't think the 200amp GFI breaker is required or needed and may even be unwanted do to nuisance tripping.Plans call for a 200a pin and sleeve receptacle fed under ground mounted at the beginning of the dock at the shore for winter disconnect. Trouble is the receptacle can be subject to submersion and ice damage in the spring with snow melt ( this is a river ). Any practical way to disconnect the docks? Service is 80 ft away.
Can 20-40 ft Boats with 240V Single Phase Be Fed with 208V Single Phase?
Yes. Most boats with 240V single-phase electrical systems can operate on 208V single-phase without any issues. The difference in voltage is small enough that it won't affect the operation of the boat's electrical devices.
Is a 200A GFI Breaker Needed?
No. A 200A GFI breaker is not required for a dock with the described configuration. GFI breakers are typically used on circuits that serve areas where there is a risk of electric shock, such as decks or pools. In the case of a dock, the risk of electric shock is minimal, as there is no permanent wiring or appliances connected to the pedestals.
Practical Way to Disconnect Docks
To disconnect the docks safely and conveniently, consider using an underground disconnect box. This box would be located near the shore, where it is protected from submersion and ice damage. The underground disconnect box would contain a circuit breaker or switch that allows the electrical service to the dock to be disconnected quickly and easily.
Additional Considerations Conduit
All wiring on the dock should be run in conduit to protect it from damage.
Receptacle Heights
The twist-lock receptacles should be installed at a height above the expected water level to prevent submersion.
Grounding
The dock must be properly grounded to the shore to ensure safety in the event of a fault.
Labeling
Each pedestal should be labeled to indicate the amperage and voltage available at the receptacles.*
Future Expansion: Consider using a larger pedestal for the first pedestal with feed-through lugs to allow for future expansion of additional pedestals. Flag for review