The ABYC has also developed a further set of color codes for boat wires (see link below). While manufacturers use these color schemes, most boat owners end up using just red and yellow wires when adding circuits.

CIRCUIT PROTECTION

With the amperage of each circuit determined, you can now plan the circuit protection you will need. That protection can be a fuse or a circuit breaker and may depend on the type of electrical panel or panels you choose.

Fused panels can easily be changed by swapping-out the fuse for a higher or lower value. Be sure and read the instructions for your electrical panel to make sure you don't overload the capacity of the panel wiring with too high a fuse or too high a circuit load.

You may have to divide up loads across more circuits, or even add additional panels. In the case of my Columbia project boat, I ended up with a main DC panel with several fused circuits, a battery test meter and a 12-volt accessory socket. I also added a secondary panel with eight additional fused circuits.

One important thing to remember about circuit protection is that the protective device is there to protect the wire, not the device the wire is connected to. In other words, the job of the fuse is to blow before the wire overheats and damages the wire insulation or starts a fire. For that reason, most electronic devices also have an inline fuse holder to protect the device itself.

WIRE IDENTIFICATION

Whether you use the ABYC color codes or not, you should identify each wire with a unique code. This code should go on each end of the wire and several places in the middle of the wire – especially in areas where wires are gathered. Searching through a bundle of unidentified red and yellow wires is a sure cause for frustration.

I use a code that I found in an old issue of DIY Boat Owner magazine. It looks like this:

• 100: Pumps, Fans, Ventilators
• 200: Internal Lighting Circuits, Ventilators
• 300: External Lighting, Mast Wiring, Nav Lights
• 400: Communication Equipment
• 500: Electronics, Instrumentation, Stereo
• 600: Safety, Security, Tank Monitoring
• 700: Heavy Current Equipment
• 800: Charging Circuits
• 900: Bonding Systems
• X1000: All AC Circuits

For example, a bilge pump wire might be labeled 100.1, a blower wire 100.2 and so on. Enter these wire IDs on the spreadsheet you use to set up the circuits. Do it for yourself and for the next owner of the boat. He'll thank you and it will help sell the boat.

When this is complete, you will have accomplished a great deal. You will have a very good understanding of the wiring that drives your boat and its systems. You will have wiring diagrams, a spreadsheet of the wires and wire sizes required, and a general idea of the needed supplies and materials. If your list is long, you can take that list and fax it around to several marine stories in order to get quotes. For a shorter list, just walk in.

But before you buy, do yourself a favor: Take some time and just sit in the boat with your circuit diagram. Visualize where the wires will run, where the conduits or wire chases will go and verify your wire lengths. You will almost certainly spot some trouble areas and add a few missing items to that growing list.

PAUL ESTERLE