Saturday was windy and cold, but our trusty electric heater raised the cabin temperature to a very comfortable 60 degrees. That was good because the majority of this job was going to take place inside the boat.
In our previous posts, we described sorting out the primary circuits at the lower helm and connecting each side at terminal strips that would serve the port and starboard power sources. For some reason, much of this wiring had been combined into a bundle of butt connectors. We removed most of that mess.
We had purchased 100 ft each of red and black #8 wire for the new wiring. Back in 1980 when our boat was built, the largest wire size used was #14 and there wasn't much of that. The majority of the helm wiring (except for the ignition and starter connections) was #16.
We had no way of really measuring exactly how long the wire run would be from the lower helm to the batteries, so we estimated and as it turned out, came pretty close. We un-spooled two lengths of red #8 and one length of black #8 and taped them together every 18 inches. Then we opened up the storage area that is just behind the lower helm and down in that storage area, removed an access panel that allowed us to get to the area under the salon floor.
We snaked the end of the wire bundle up from the storage area to behind the lower helm and there we connected the cables to our terminal strips.
Next we had to come up with a way to route our three #8 wires back under the salon floor to the engine space. We did that by taping the ends of our wires to our boat pole and then extending the boat pole one section at a time until it poked out a small opening (where the control cables run) just forward of the engines. Then we had to crawl down behind the starboard engine, grab our wires and cut the tape so we could extract the boat pole. Easy to describe but one hell of a lot of work to do.
Then it was a matter of running the cables along the bulkhead that, just above, supports our sliding glass door and down to the batteries. At this point, we didn't know which red wire was which, so we made a temporary +12 volt connection to one of them and then went back to the lower helm and identified our hot wire.
We connected our black ground wire directly to the forward (port) battery bank since that was the most direct and convenient place. The negative terminals of all four batteries and both engine blocks are connected together
We don't like to make connections directly to the batteries (the ground, in this case, is an exception) so we connected our port and starboard +12 volt red #8 wires to the output terminals of our battery switches. No fuses? No, but we did install two very nice surface mount 40-amp resettable circuit breakers directly below the battery switches. The whole thing made a nice neat installation.
Why 40 amps when adequate protection for the lower helm would be at most 15 amps? We intend to add new wiring the bridge as our next step and we sized the circuit breakers to accommodate that, although that took us a while to figure out. Here's how we got there, using a worst case situation.
VHF radio on transmit = 15 amps
Radar on = 20 amps
Air horn compressor = 20 amps
Navigation lights = 2 amps
Chart plotter and other minor accessories = 4 amps
Some of these loads are intermittent but it is possible that in bad weather we could have the radar on, and transmit on the radio and have to sound a fog signal with the air horn, all at the same time. (Actually, I think we have been in conditions like that.) Not a good time to have to reset a circuit breaker.
Merry Christmas to everyone and remember, the shortest day of the year is past.
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