A/C electrical panel not grounded

[Polar777]

Hello Folks,
I have a concern about my A/C electrical system and would appreciate any help the group can give.
I have a 1980 Mainship in salt water at a marina, usually connected to shore power.
Let me give you some background, at the beginning of last summer I had a fuel leak in my 15 year old fuel tanks due to electrolysis. The tanks were installed, I think poorly, with dissimilar metals attached. In any case the zincs were in good shape, so I decided to install a galvanic isolator.
When doing the work I found that all of the ground wires were intentionally removed and taped so as to not touch each other.
Does anyone have a guess as to why someone would intentionally do this?
Could this have produced my tank electrolysis in the first place?
I have plenty of experience with AC on the land but none on water. I will get an electrician in to do the work but I have a feeling there is more to this than meets the eye, so I would like to understand what is going on.
Thanks in advance for your help.

 

[Comodave]

Welcome aboard. The grounds should not be disconnected. They should go to a bus bar and the shore power green should be connected to that bus bar also. As to why they were disconnected, who knows? Someone that doesn’t understand marine electrical work must have done it. Get them connected properly ASAP. They are there for a reason, and the reason is safety. Have a certified marine electrician come check the boat, and make sure he/she is certified.

 

[STB]

Out of curiosity, does the boat have an inverter?

People do crazy things like this when they plug into a modern marina with GFCI or install ELCI and it pops because of leak current. No groun, no leak current. But as Commodave says, also no safety.

If you go to reattach them and your current dock doesn't have GFCI, you may want to check for leak current with a meter before screwing down each one.

Be careful. I'm about to describe a live circuit-on procedure.

Trace back a dangling grounding conductor to find the hot wire to find the breaker to find the associated circuit.. Turn it off. Set your meter for AC in a range good for 120V. On my meter that is 200V. Alligator clip the black wire to the ground bus. Alligator clip the red wire to the dangling grounding conductor. Protect the metal from exposure using the alligator clips' boots and power the circuit. Turn the circuit on and fully load it. Check for any voltage. There should be none or the smallest trace. If this is the case, turn off the circuit breaker, connect the grounding conductor to the bus and move on to the next one.

If you do get any significant voltage, it could be from induction from parallel wires but with virtually no current flow. Disconnect the clip at the bus, set the meter to a very small current range...something that has enough resolution to reliably measure something like 0mA to 100mA. Reconnect the alligator clip and adjust boot. Turn on meter. Verify near 0mA current flow and power and load circuit.

Most marina GFI or GFEP devices will trip at 5mA or 30mA leak current, respectively. Most on boat ELCI's at 30mA of leak current. So, if the sum of the leak current you measure across all of those gets to that level, you could trip one.

You can also make a fitting to expose the ground wire for testing between your boat's shore power cable and the pedestal.

But, again, don't do any of this unless experienced working live on 120VAC. An electrician is always best. Really.