grounding at sub panel that does not hane a equipment ground conductor run with feed

[dvolsr1]

i have a friend who has a fixed boat dock and power from main panel TO A SUB PANEL was run without a EGC .( this is a fresh water lake) question one ,do you isolate the bare netural. 2. do you ground the panel to a ground rod.or can you isolate netural and not gnd. panel to gnd. rod and use a 2pole gfci for shock protection from faults . i know the proper fix is to run a EGC, BUT THI A 300 FT. UNDERGROUND CABLE .THIS IS A 240 VOLT PANEL.

 

[rlundsrud]

Anything besides running the EGC is not code compliant, it is the correct thing to do regardless of difficulty. With that said, installing a gfi at the main panel that protects the entire sub panel would be a good idea as an interim fix until a EGC can be installed. Also, since this is a separate building, you should have a ground rod installed. The neutral should be isolated from ground and a separate ground bus should be installed for branch circuit grounding.

 

[iwire]

Anything besides running the EGC is not code compliant,

That is not correct.

The code allows using the neutral as the grounding means to remote locations in existing installations.


The the neutral must be bonded to the enclsure at the remote location along with a grounding electrode system at the remote location.

 

[don_resqcapt19]

That is not correct.

The code allows using the neutral as the grounding means to remote locations in existing installations.


The the neutral must be bonded to the enclsure at the remote location along with a grounding electrode system at the remote location.

Something I would never even think about for a dock application, not even if it was code compliant based on the rules when the circuit was installed.

 

[ptonsparky]

When you say 240 volt panel, does that mean it is supplying only 240 loads? No 120 volt loads.

 

[kwired]

I agree that for older existing installation NEC would permit grounding the neutral at the load end of the feeder.

I also agree that for this application at a boat dock, I may still not like the use of said exception - the equipment grounding conductors will be at same potential to ground as whatever voltage drop is on the neutral - may still create some hazards in/around the boat dock.

You can install a 240 x 120/240 transformer and separately derive a new system at the boat dock, or depending on what was originally ran - if possible to pull in a EGC it still may cost less.

Fresh water lake is even bigger shock hazard then salt water - less conductivity of water makes smaller voltage gradient zones - exposing people to higher touch potential over same distance.

 

[Little Bill]

This install would be at risk of being condemned in my state if it was a public dock or marina. They currently have an aggressive program concerning docks and marinas. The state head electrical inspector is currently inspecting these areas. If he finds problems or potential problems he writes up a correction notice and the owners have a time limit to get them fixed or risk being shut down. Grounding/bonding/GFCI is the main thing they are looking at.
There are specifics that I don't recall but that is the gist of it.

Maybe Augie47 could fill in or correct what the specifics are.

 

[kwired]

This install would be at risk of being condemned in my state if it was a public dock or marina. They currently have an aggressive program concerning docks and marinas. The state head electrical inspector is currently inspecting these areas. If he finds problems or potential problems he writes up a correction notice and the owners have a time limit to get them fixed or risk being shut down. Grounding/bonding/GFCI is the main thing they are looking at.
There are specifics that I don't recall but that is the gist of it.

Maybe Augie47 could fill in or correct what the specifics are.

Though that is probably not a bad thing, there are still electrocutions that happen at code compliant docks/marinas that are because of voltage drop on the service neutral or even on the POCO MGN that is also present at the dock on the equipment grounding conductors which are ultimately bonded back to the service neutral and eventually the POCO MGN. One can drive all the ground rods you want and have little improvement and GFCI will not detect this problem. I don't have a solution for it that complies with NEC.

 

[Little Bill]

Though that is probably not a bad thing, there are still electrocutions that happen at code compliant docks/marinas that are because of voltage drop on the service neutral or even on the POCO MGN that is also present at the dock on the equipment grounding conductors which are ultimately bonded back to the service neutral and eventually the POCO MGN. One can drive all the ground rods you want and have little improvement and GFCI will not detect this problem. I don't have a solution for it that complies with NEC.

With a few electrocutions taking place around docks/marinas in the last couple of years the state was tasked with making sure everything was being done that could be concerning up to date installations. If I'm not mistaken at least one of the deaths/incidents was preventable had everything been done correctly. I think they were too lax on the areas in the past. Most docks/marinas did their own wiring (similar to what you see on farms :roll They were never checked or inspected for the most part. Even when they were inspected I don't think enough focus was placed on possible hazards around these areas. Probably because some inspectors were not knowledgeable enough on the subject

One thing they are requiring is GFCI protection from the source to the dock areas. If that's not possible or feasible then each branch circuit has to have it. I know that won't prevent all hazards but will go a long way to make them safer.

 

[kwired]

With a few electrocutions taking place around docks/marinas in the last couple of years the state was tasked with making sure everything was being done that could be concerning up to date installations. If I'm not mistaken at least one of the deaths/incidents was preventable had everything been done correctly. I think they were too lax on the areas in the past. Most docks/marinas did their own wiring (similar to what you see on farms :roll They were never checked or inspected for the most part. Even when they were inspected I don't think enough focus was placed on possible hazards around these areas. Probably because some inspectors were not knowledgeable enough on the subject

One thing they are requiring is GFCI protection from the source to the dock areas. If that's not possible or feasible then each branch circuit has to have it. I know that won't prevent all hazards but will go a long way to make them safer.

GFCI on a long feeder is potentially going to trip often just from capactitive leakage over the long run, protection at or near the load end of the feeder would be a better design, or as you mentioned on each branch circuit is probably best.