I bought a second hand boat in 2024 (built 2008) and I have recently taken the cover off the 3600W isolation transformer (original from build) to check following an overheating trip and was surprised to see an earth link in place between J34A and J34. If I have understood the manual correctly this should not be in place when the boat is in the water and connected to shore power which it is now. Therefore if I remove this link, are there any other corresponding changes required to revert from “boatyard safety” configuration to “in the water” configuration? Apart from operating the output side RCD test button are there any other checks I could usefully do after removing the link? As you can see from the photo the output neutral grounding between J33 and J21 is correctly in place for RCD function. Thanks
Removing the PE link wire from J34 to J34A is all you need to do.
With the system isolated and turned off use a multimeter to check for continuity between the input shoreline PE and the output boat PE to make sure that they are now separated.
You do not mention your boat type and if there is risk of galvanic corrosion of any submerged metal parts, hence a check for any such corrosion would be a good idea.
Thanks for your reply and confirmation of the task.
It is a steel inland waterways boat, so yes I am now concerned the galvanic protection has been bypassed for at least two years since it was taken out of the water for 2 pack blacking and new anodes in 2024 after I bought it.
It is located in a Port of London deep water marina (brackish water). My next door neighbour has been a GRP cruiser, and nearby historic converted dutch commercial barges and wooden craft. I have checked an anode with an underwater borescope and it is certainly fully intact and doesn’t look that worn visually, so hopefully the anodes and the circumstances above have mitigated the impact on the hull which I will now check around the waterline the best I can as I understand that is the most at risk section.
Thanks again and kind regards
Ian
I understand your position, I have a narrowboat on the canal network and some of the horror stories of galvanic corrosion are always concerning especially as electrical bodges on narrowboats are common. On my 5 year old new build I specified an IT and carried out a continuity check from shore socket PE to hull grounding point to confirm a lack of connection. Hopefully it all turns out OK.