High voltage supplied to a floating dock

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Fred B

Fred B

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Upstate, NY
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Electrician
Customer has purchased an electric boat that requires an EV charger 50Amps. Charger cord limited from mfg specs to 13ft and dock mounted charger pedestal. Dock is a floating dock that needs to be at least 40ft from shore for boat to approach. Dock is sectional at 10ft intervals and needs to be removed seasonally, so the electrical supply needs to be able to be removable and water tight. Looking for the possibility of wiring each section independently with a flexible disconnecting means between each section, disconnects would need to be watertight. Anyone have experience with this sort of installation or suggestion as to products that would work?
Additionally the distribution panel needs to be a distance away to get above the seasonal spring flood elevation. Historically has a flood elevation of 5ft above normal lakes datum plane.
 
Looking for the possibility of wiring each section independently with a flexible disconnecting means between each section, disconnects would need to be watertight.
Don't think 555.9 will allow that.
 
augie47 said:
Looking for the possibility of wiring each section independently with a flexible disconnecting means between each section, disconnects would need to be watertight.
Don't think 555.9 will allow that.
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It looks like "if" I keep the connectors at least 12in above deck it could be doable?
But then there is section 555.13(A)(2) that makes it appear that the should be a method to accomplish connections of sections under deck per 555.13(B)(4).
 
I would see if the dock manufacturer can have a chase built into the dock for you to pull type G or W cable through. IMO it would be better to plan on installing and removing the cable each season than dealing with some kind of connections at each section. 40' is not all that far. They may want a chase for a water line also.
 
oldsparky52 said:
I would see if the dock manufacturer can have a chase built into the dock for you to pull type G or W cable through. IMO it would be better to plan on installing and removing the cable each season than dealing with some kind of connections at each section. 40' is not all that far. They may want a chase for a water line also.
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I was thinking along the same lines. The electrical installation would be simpler, cheaper, and less prone to damage and degradation during usage and also the seasonal installation/removal of the dock. Basically less things to go wrong.
 
I envision a marine power center at the boat that a cable would connect to (probably a #4, maybe a #6), the cable come out from the dock and is routed to a disconnect at the beginning of the dock. This disconnect could house the GF protection or you could put it back at the house.

End of season, disconnect the cable at the power center and the shore disconnect, remove, and reinstall next season.
 
oldsparky52 said:
I envision a marine power center at the boat that a cable would connect to (probably a #4, maybe a #6), the cable come out from the dock and is routed to a disconnect at the beginning of the dock. This disconnect could house the GF protection or you could put it back at the house.

End of season, disconnect the cable at the power center and the shore disconnect, remove, and reinstall next season.
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That works for a solid single section dock, but this is a floating multi section dock that needs to flex at the joints. Will have marine power pedestal on the end of dock and a shore panel disconnect, now issue is getting from shore to power pedestal.
Marino makes a 250V 50A cord shown below in 12 ft, 25ft, and 50ft. They list the cord for bringing shore to ship power, listed as watertight and UV protected. This seems it would be allowed under 555.13(A)(2) 1 and 2. But 555.13(B)(4)(b) says where portable power cables are used as permitted in 555.13(A)(2)(2), "there shall be an approved junction box of corrosion-resistant construction with perminantly installed terminal blocks on each pier section to which the feeder and feeder extensions are to be connected." What is a "perminantly installed terminal block"?
Supplier says the plug ends of the cord are about 2.75in across so getting it to pull thru the framing members would need to meet the criteria in 555.13(B)(4)(a)(5) shall be "protected against chafing by permanently installed oversized sleeve of nonmetalic materials." That's required to be quite big for the connections to fit thru.

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Fred B said:
It looks like "if" I keep the connectors at least 12in above deck it could be doable?
But then there is section 555.13(A)(2) that makes it appear that the should be a method to accomplish connections of sections under deck per 555.13(B)(4).
Click to expand...
I don't see anything there that says the connection locations are not required to comply with 555.9.
 
don_resqcapt19 said:
I don't see anything there that says the connection locations are not required to comply with 555.9.
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Other that 555.13 requires for sectional piers to have an appropriate j box at each joined dock section. And allowance of use of cord for feeder.

Was looking for equipment for the installation of the shore power and came across this regulation, anyone know what this item is? In some ways the description I saw sounded like an AFCI in operations.
ABYC regulation E–11.11.1 states:
An Equipment Leakage Circuit Interrupter (ELCI) shall be installed with or in addition to the main shore power disconnect circuit breaker(s) or at the additional overcurrent protection as required by E–11.10.2.8.3 whichever is closer to the shore power connection.
 
An important point is whether the floating dock when assembled is considered multiple sections or one assembly. Around here they don't remove the floating docks so they are considered one assembly once the sections are assembled (they are tied together). The point is I don't think you need to have a junction box on each "section" if the "sections" are securely fastened to each other.

Years ago I looked at where that requirement came from and it's an interesting history. IMO that requirement has morphed from its original intention and is not something that should be in the code.

How is the dock assembled? Are the sections bolted together or just some kind of retaining pin? Do you have a drawing of the dock construction, or have you seen one?

You really need to speak with the AHJ.

I think Bender has the monitoring equipment you want, others do too but Bender was the go to unit about a decade ago. I don't know what's being used now though. https://www.benderinc.com/products/ground-fault-monitoring-grounded-overview
 
oldsparky52 said:
An important point is whether the floating dock when assembled is considered multiple sections or one assembly. Around here they don't remove the floating docks so they are considered one assembly once the sections are assembled (they are tied together). The point is I don't think you need to have a junction box on each "section" if the "sections" are securely fastened to each other.

Years ago I looked at where that requirement came from and it's an interesting history. IMO that requirement has morphed from its original intention and is not something that should be in the code.

How is the dock assembled? Are the sections bolted together or just some kind of retaining pin? Do you have a drawing of the dock construction, or have you seen one?

You really need to speak with the AHJ.

I think Bender has the monitoring equipment you want, others do too but Bender was the go to unit about a decade ago. I don't know what's being used now though. https://www.benderinc.com/products/ground-fault-monitoring-grounded-overview
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We have these all over around here. They have pins that allow each section to move independently of the others. This is the first that is needing to have this level of power delivered out to the end. Many of the docks to have powered dry docking by most just pull an extension cord out onto the decking to plug it in when they need it. Not necessarily legit but that is what they do.
 
Fred B said:
Other that 555.13 requires for sectional piers to have an appropriate j box at each joined dock section. And allowance of use of cord for feeder.
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Click to expand...
I still see nothing that modifies the terminal location in 555.9. 555.13 requires the junction boxes, 555.9 tells you where the junction boxes are permitted to be located.
 
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