Continuing with the reporting of common findings during the ABYC safety inspection session in Annapolis last month, we touch on what is a recurring theme, wire nuts. The photo below points out the wiring behind the scenes on a boat where these little electrical devils where used.
The yellow arrows are pointing to the wire nuts.
One of the problems with wire nuts is that in spite of all the talk over the years about how bad they are, equipment vendors to this very day still provide them with installation kits for equipment intended to be used on boats. For those of you that may be new to this whole issue understand that these devices are intended and engineered for use only with single strand copper conductors such as the wire used at your house. For marine applications, multi-strand copper wiring is all that is acceptable. The problem with the wire nuts is that as they get threaded onto a two (or more) wire splice, the threads inside the wire nut cut into the fine copper stranding and actually can begin to break the individual strands. The bottom line? Some loss of theoretical conductivity of the piece of wire in question. This in turn can create electrical resistance, and as I’ve said here many times before, the primary byproduct of excessive electrical resistance is heat. Enough heat and you have fire. You get the rest………….