Okay, returning to the subject of planning an
electrical system, I offer a trick I used when redesigning and installing my overhauled circuit panel on WILDERNESS. First, I wrote down a list of all the electrical stuff I could possibly think of including aboard the boat, divided into 12 VDC and 110 VAC columns. I didn't bother, at first, with trying to put them into separate circuits, I just wanted to see how crazy things could get. There were a whole bunch of electrical goodies that weren't included in my original six circuit breaker panel when I built the boat.
Then, I set up an Excel spreadsheet to handle the next phase. On sheet one I listed all of my "wish list", along with the
current and voltage needs, which I Googled the specs from the manufacturer.
Then, in an adjacent column, I estimated the anticipated hours of use per 24 hour day, and set up a calculation format to give me the amp-hours I might expect to consume per day per unit.
Now, I had a better idea of how battery capacity I needed, and what would be required to recharge my system's needs.
On sheet two, I began to create the circuits that would be needed. I had two
cabin light circuits (port and starboard, in case I blew a circuit and needed light to
repair it). I made circuits for
navigation lights, communication and electronic
navigation circuits, pumps, 12VDC outlets, etc. Then I distributed my wish list into these circuits to see how much electricity they needed, per circuit, if I should go crazy and turn everything on at once. I did the same for the 110 VAC circuits.
Now, I could order a panel from Blue Seas with all the circuit breakers I needed, and some extras for the future. Because everything was already in Excel, I could now consider how to distribute the available
current out to the myriad goodies. From the books mentioned, and other sources, I had decided to use a distribution system for wiring. This meant that one wire, of sufficiently large size, went to a buss, from which radiated smaller gauge wires to the various
parts of the boat where the
power was needed for the individual circuit. Having a
center cockpit boat made this particularly attractive because there are several locations where
power for lights, for example, are needed. The wires went to
remote distribution busses in different compartments of the boat. From the
remote buss, they went directly to the light or other unit needing electricity.
How to keep track of everything and how to determine the correct wire size was an issue resolved easily enough using the Excel spreadsheet. I just made a column for the current
consumption, another for the length of the wire run (out and back), then made a column for the wire size needed to keep voltage drop down to 3% or lower. Each circuit breaker was given a circuit number. The distribution leg was given a sub number, and the final leg to the lamp was given a third number. For example, a wire labelled 1-3-2 could mean circuit one (Cabin Lights Portside), aft
cabin,
galley sink overhead lamp. A label maker made keeping this stuff under control was easy.
I could plan all my circuits out in advance, build wire harnesses to remote distribution busses, and label everything in advance using the spreadsheet. Not only did it work, but it made
installation MUCH faster and error free. There were very few mixups and a wonderful sense of accomplishment when I would find a loose wire that hadn't been connected yet to some unit I hadn't yet installed. It has kept me saner than I might otherwise have been.
In summary, decide what you want on your dream system. Break it down as to electrical needs. Put it into relevant circuits. Calculate the wiring sizes needed from the battery, through to the unit (and back to ground). Make a printout for reference. Label each and every wire in an orderly and simple numerical code (add words, as well, if that helps). Start at the circuit breaker, wire outward to the
destination, labelling as you go. Flip the breaker on, switch on the unit, and congratulate yourself.
. (Impedance Z=R+jX and remains impedance whether X is zero or not. And a 10pF capacitor, for example, remains 10pF regardless of frequency).
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