u/ahobonamedjoe

Customer was reporting issues with tingling in the water due to 3v of NEV issues from utility.

Correcting the bond of every metal part on the dock frame lowered the voltage from 3v to 1v for one customer, but had some areas with 1.4v in the water. I also added a local ground rod at the shoreline, bonded to the dock frame and EGC.

For another customer, it had no effect and actually raised it from 1.8 to 2.4v in the water.

According to the Duke Energy engineer:

Solution 1:

Isolation Transformer

Separate ground rod for this system

This is the actual letter from my local utility Duke Energy.

The second customer sent over this transformer and says "My neighbor says it works great"

https://bluemarine.com/products/victron-isolation-transformers?_pos=2&_sid=c496348e2&_ss=r&variant=45470493081896

Solution 2:
He has seen electricians who run everything in plastic boxes and do not ground the metal on the dock at all.

The obvious problem I see with this is that if there is ANY insulation failure touching the frame, the whole dock is energized.

Previous post:

https://www.reddit.com/r/electricians/s/7FGRsE3o4Q

Licensed Electrician in SC. Power has been disconnected.

Aluminum dock frame to water: 1.7–1.8V AC with the feeder connected. Drops to zero when the dock cord is fully unplugged (hot, neutral, and ground all open).

Voltage persists with the branch breaker off AND with the service main open, so it's arriving on the neutral/grounding system, not the branch circuit. GFCI upstream never trips, it is fairly new.

Adjacent marina reads higher (2.8–3.1V water to ground pin) with all its breakers off. Lifting the marina's neutral drops it from ~3V to ~1V.

Could this be a utility issue? Would a highly sensitive clamp meter be helpful here? I was looking at the Fluke 368.

I was wondering what forks exist as I can't find much info on it