Triton, Follow Beausoliel's advice. Do a couple more things as well: Create an Excel file at the outset of this adventure. On sheet one do the following: Label across the top the following: Circuit name
and number, electrical device
powered by this circuit, amount of time
in 24 hours that the unit is probably going to be used, the current draw
of the unit, the product
of the current
draw and the 24 use cycle. This provides you with an idea of how much juice you expect to use in a day's time, an idea of how much juice you are funneling through each circuit breaker, and an idea of how big a battery bank you will need.
Start sheet two and label the top: Circuit
name and number, distance
to the unit and back to the panel, wire size.
Under the circuit name list the device
and fill in the empty column info, using a wire sizing software
such as Blue Sea Systems
# or the West Marine
catalog. At this point you might consider a distributed system where a circuit powers busses that then feed power out to the various lamps, etc, as opposed to individual wires from the panel to each device in the boat.
Now, consider the toys that you might want ten years from now. Do you have spare circuits available, conduits or existing wiring
to carry the power to those future loads? You will have to plan for it sooner or later. It's easier to do it sooner and set up the supply wiring, even if you don't install the breakers and busses now. You'll even get a head
start on making sure you have the battery capacity for the future.
Now you can go completely crazy and give each device and length of wire a label to identify it when you string it in the boat and have to identify it later on (it WILL happen). I label my stuff with the circuit number first, followed by the feeder wire lable, then the wire going from the distribution buss to the device. For example: 01-01-01 means PORTSIDE CABIN LIGHTS CIRCUIT BREAKER (01)
connected to the FORWARD CABIN LIGHTING CIRCUIT BUSS (01-01)
,connected to the FORWARD CABIN BUNK LIGHT, INBOARD(01-01-01).
I made up the spreadsheets, followed the wire size requirements for 3% line loss, bought the lengths of wire needed according to the sheets
, pulled the wires and labeled them at each end, then connected them to the origin and destination
for each label. Then I colored in the completed lines to show my progress and where to begin where I left off.
With 16 DC circuits and several AC circuits, it really helped to keep me (somewhat) sane and solvent. My panel is in the center of the boat, with five major conduits leading to various parts
of the boat. You want to pull all of the wires in any one harness at the same time, meaning they need to be precut, prelabeled and tightly bundled. Doing so also adds some calculations to the current
draw, as does passing them through engine
spaces (better to use conduits). When this boa constrictor arrives at a distribution center, it really pays to have stuff labeled.