It’s an enduring truth that appearances can be deceiving, especially with electrical systems. When I inspected Summer Dance before buying her, the electrical system looked like one of the boat’s strong suits. It had an upgraded panel and a new battery. The wiring was all original except for spliced connections to the panel. There weren’t any added accessories so the system was simple and I expected it to be relatively problem-free. Granted, I’m no marine surveyor and if I had ordered a survey, it would have caught many of the problems that I later discovered.
The first problem that I had was an intermittent stern light connection. Next was an intermittent primary ground wire. When I removed and disassembled the West Marine breaker panel to clean it, all the spade connectors had some level of salt water corrosion. Then the main ground conductor failed entirely and I had to replace it. Upon further inspection, all the conductors to the battery and breaker panel showed extensive corrosion for several feet under the insulation that made them brittle and prone to breaking. There was no overcurrent protection at the battery either. Since electrical system failures are a major cause of onboard fires, it’s also true that what you cannot see can hurt you.
Rather than connect the new accessories to an unsafe and crumbling foundation, I decided to rewire the boat so that everything was new and built (as close as practicable) to the American Boat and Yacht Council standard E-11 – AC & DC Electrical Systems on Boats.
I say “as close as practicable” to the ABYC standards because the ABYC is intended for boat manufacturers and service centers, not boat owners. Their standards documents are not generally available to the public. You have to pay an expensive membership fee and then purchase the standards for $195. Those costs would exceed this project’s entire cost for materials, not exactly practical for the average boat owner, let alone the $tingy Sailor. However, a copy of the E-11 2006 draft can be downloaded online and excerpts of the current standard are also available online for information like the wiring size tables and color codes.
Disclaimer: I make no claims that the methods described in this article meet the current ABYC E-11 standard in any way. The reader is solely responsible for any consequences of following this advice and is encouraged to seek professional assistance if they are unfamiliar with this subject.
Planning a new electrical system consists of:
- Take inventory of the existing and planned devices
- Group the devices into like-function circuits
- Calculate the total potential load of each circuit
- Select a new panel with at least as many breakers as the planned circuits
- Assign the circuits to adequately sized breakers in the new panel
- Measure the round trip distance to each device from the panel or other connection location
- Calculate the correct wire gauge and determine the color for each circuit according to the E-11 tables
- Draw a schematic diagram of the location of each device and its conductors for easy reference
When you know all of the wire lengths, gauges, and colors that you’ll need, you can order the marine grade wire, heat shrink crimp connectors, and other installation supplies from online retailers like GenuineDealz.com and Del City. For reference, this project cost me about $220.
With all the supplies in hand, the installation is pretty straightforward if you’re familiar with DC power systems. If not, I recommend that you read a good book about marine electrical systems like Sailboat Electrics Simplified by Don Casey.
What follows are some installation tips from my project that are specific to the C-22 or similar trailerable sailboats.
Your sailboat likely has a single, deep cycle battery and no starter motor. To meet the 7″ overcurrent protection rule, install an MRBF type fuse block on the positive post. If you have an outboard motor charging circuit (fused) or an onboard shore power charger, connect them upstream of the fuse block. You might also consider installing a battery master switch if you have a really complicated system and long wire runs. If you’re planning to install a solar panel to charge your battery, check out Solar panels for boats: an easy installation guide.
Ground bus bar
The original wiring in most small sailboats has no separate bus for the negative conductors. Instead, all connections terminate at the breaker panel. Adding a dedicated negative bus bar really helps to organize the wiring and simplifies the panel connections.
Besides the power wiring, I also had some signal wiring to accommodate: the NMEA signal from the GPS to the autopilot and the stereo rear channel speaker signals for connecting to my crib board mounted cockpit speakers. I also wanted to install two 12V power outlets in convenient locations in the boat. I also needed to mount a switch for the lazarette LED strips. I solved all these issues by fabricating an aluminum accessory panel and mounted it in the wood trim next to the companionway. The panel makes it easy to connect my handheld GPS to power and the autopilot, switch on the lazarette lights, and connect the cockpit speakers. I installed an extra switch for future use. I installed the other 12V outlet in the side of the stereo enclosure where it’s handy for connecting an oscillating fan.
The original wiring in C-22s (and I suspect in many other small boats) is mostly embedded in the fiberglass itself. This makes the wiring mostly invisible but it also makes it mostly unserviceable. So, you can’t replace all the old wiring with new, you have to run the new wiring in addition to the old wiring and abandon the old in place. This also means that you have to find places to contain and conceal the new wiring.
The best place for this in the cabin area of a C-22 is in the channel formed by the hull to deck joint. The channel runs nearby most places where you will want to mount lights and accessories. In first generation C-22s, this channel is covered by teak trim that you can easily remove. I found it helpful to tape the wires in place until I was finished and then replace the trim. A notable exception is the mast wiring jack. There’s nowhere to conceal new wiring to the jack in the deck near the mast step. Since mine had never been connected before, I used the existing wiring, which was still like new. If you don’t want to use the existing wiring, you can mount a cable to the cabin ceiling behind the curtain track or in some kind of covering.
Other good locations are the underside of the hull liner for traversing the hull and the underside of the cockpit sole for running wire aft. I used 3/4″ flame retardant (required per E-11) split loom held in place with wire ties (18″ max. apart per E-11) through self-adhesive mounting pads. In older boats like mine, you might need to clean the mounting locations first with rubbing alcohol or another solvent to insure good adhesion. The mounting pads won’t stick to old, chalky paint.
Since replacing the wiring, I haven’t had a single electrical problem. I know exactly what every wire is and I can access every inch of it if a problem ever does come up. More than likely, I’ll make more modifications and upgrades.
Would you like to be notified when I publish more posts like this? Enter your email address below to subscribe to this blog and receive notifications of new posts by email. You will also receive occasional newsletters with exclusive info and deals only for subscribers and the password to the Downloads page. It’s free and you can unsubscribe at any time but almost nobody does!