I am presently constructing a diesel/electric narrowboat and have a knotty problem regarding earthing.
I am constantly being advised to consult an electrician, but the advice received would only be as good as that one person's knowledge so I have turned to this blog in the hope of a great wealth of knowledge.
The narrowboat contains the equivalent of normal domestic 230v 13amp ring mains (UK) to supply various equipment. There are 3 potential sources of supply, a mains shoreline connected through a galvanic isolator, a fixed onboard diesel generator and a 600watt inverter powered from the battery bank.
All knowledgable sources state that when switching between these various sources a "break before make" switching must be employed. This is no problem as all supplies are carried through 16amp industrial sockets and plugs, which obviously have to be disconnected before reconnecting.
The problem lies with how the earthing is arranged. Shorepower has its own PME and is no problem through the GI. The generator was designed with floating earth but this shows up in tests as reversed polarity because a earth / neutral link is not installed in the generator. Knowledgeable advice on the web states the solution is simple to change a generator from floating earth to "grounded"earth. "Put an earth /neutral link in the outlet plug, not in the generator and provide an earthing spike." The first one I can do, but not in the plug, it will have to be in the generator socket, because the plug is transferred to the shoreline source. The second, providing an earthing spike is impossible on a moving narrowboat.
My question is, that if all power sources are "earthed" to the central earthing point on the boat side of the galvanic isolator will this provide a safe installation?
I am constantly being advised to consult an electrician, but the advice received would only be as good as that one person's knowledge so I have turned to this blog in the hope of a great wealth of knowledge.
The narrowboat contains the equivalent of normal domestic 230v 13amp ring mains (UK) to supply various equipment. There are 3 potential sources of supply, a mains shoreline connected through a galvanic isolator, a fixed onboard diesel generator and a 600watt inverter powered from the battery bank.
All knowledgable sources state that when switching between these various sources a "break before make" switching must be employed. This is no problem as all supplies are carried through 16amp industrial sockets and plugs, which obviously have to be disconnected before reconnecting.
The problem lies with how the earthing is arranged. Shorepower has its own PME and is no problem through the GI. The generator was designed with floating earth but this shows up in tests as reversed polarity because a earth / neutral link is not installed in the generator. Knowledgeable advice on the web states the solution is simple to change a generator from floating earth to "grounded"earth. "Put an earth /neutral link in the outlet plug, not in the generator and provide an earthing spike." The first one I can do, but not in the plug, it will have to be in the generator socket, because the plug is transferred to the shoreline source. The second, providing an earthing spike is impossible on a moving narrowboat.
My question is, that if all power sources are "earthed" to the central earthing point on the boat side of the galvanic isolator will this provide a safe installation?