WIRING: A NOVICE'S APPROACH
I didn’t trust the wiring, mostly because I didn’t understand it. Like most old
boats various electric gizmos had been added, removed, and relocated over the years and with that grew a patchwork of splices,
new branches to circuits, wires that went nowhere, and all sorts of confusion. I decided to replace pretty much everything.
I even drew up a plan after consulting a number of sources about marine wiring. The plan was more to walk me carefully
through the process since I was pretty slow when it came to understanding volts and amps and circuit paths. Note that
I said was pretty slow. I learned a lot doing this.
I also had some issues with the original layout.
Like you see so often, everything switched on or off at a main fuse panel. It never made sense to me to have to holler
down or send someone below to switch on the running lights, for example. Why not have a switch for them at the helm
– along with switches for the foredeck light and the steaming light? And why not have a switch for the anchor
light be located where I can see it and reach it when I first wake up?
Another reason for the plan was, since
I was gutting the boat, a lot of the wiring changes and the additions of electronic ignition, engine gauges, sailing instruments
and navigation electronics would be done all at once, without the benefit of testing things as I went along. So I wrote
up this big tome that describes the system and tells what each wire does and where it goes. As first written it had
flaws that became apparent as I verified my logic. I corrected and adjusted the plan as I implemented it. It will
be a terrific aid for a surveyor or next owner trying to understand what he sees of all the electrics.
The basics are these: House and start batteries have their own separate switches and neither
can be used for the other without going through a lockable third switch. This eliminates the risk of wearing down the
start battery with the CD player and other toys. The charge circuit is connected to the house battery and an automatic
switch called a combiner engages to charge both batteries in parallel after the house battery recovers to a certain level.
Fortunately the Atomic 4 does not require much oomph to start, so a deep-cycle group 27 wet-cell battery works well as a starting
battery. Normally a punchy car-type battery is preferred for starting, but that would mean uneven loads for the charging
circuit when parallel charging both batteries. With this layout group 27 wet-cell batteries are used for both house
and start banks and the whole setup seems quite happy.
The main circuit panel is just that – for main circuits,
not electric gizmos. Each breaker switch supplies current to a circuit but does not turn on any appliances. Those
are switched downstream, generally after one of several remotely located fuse panels. I did this for two reasons.
Fuses are more sensitive and will trip sooner than circuit breakers – good for electronics while the slower breakers
are better suited for the main lines. It makes it easier to trace problems as well.
So how did everything
work out when I followed the plan and finished the wiring? It didn’t. With great fanfare in mid-July of
’02 I turned on the battery switches, flexed my fingers, grinned for the hushed family, and turned the ignition key.
Not a sound. Gawd! Where do I even begin? I walked away from it all while my son, then a student of electrical
engineering and now an actual electrical engineer, took pity and decided to have a look. It wasn’t long before
he announced he found the problem. His brilliant dad neglected to connect an ignition wire to the coil. It wasn’t
in the plan even though such a wire appeared on any number of basic engine wiring diagrams that I had at the time. After
stringing a wire and trying again with the key – VROOOM! And there was dancing.
Some advice if you
are thinking of a similar wiring job on your boat. Try to determine as best you can what you will need in the way of
wire, connecters, terminals and switches etc. Bought piecemeal this stuff costs a bloody fortune. I learned later
that normal marine stores are not the place for electrical components. Look online for places that sell marine wiring
in bulk. They are there.
I also should admit that, for me anyway, rewiring was hugely time consuming,
not to mention tough physically. If you put appliances where you want them, like engine gauges in a winch island, you
may not be able to see where to connect the wires. Get used to using mirrors, scraping arms and fingers,
and cramming things, including you, into impossible spaces.
The results are very pleasing, however.
Everything is located so logically and right where, I anyway, can see and operate any appliance very quickly and easily.
Of course, the system is not as complicated as on boats with everything from refrigeration, A/C, computers, and everything
imaginable. But I dread having to look at a 50-switch panel to see if something is on or not. They are impressive,
but a pain since I have to find my glasses to see anything on them.