Wiring a boat can seem like a simple proposition for a boat builder. After all, the principles of electricity don't change when you're on the water. But there are concerns that any marine wiring job needs to keep front and center. So before you design a circuit diagram for your next boat, keep this in mind.
Constructing an electrical system for a new brand of boat starts and ends with safety. Keep in mind -- especially if you're making pleasure craft or other boats used by inexperienced sailors -- that you'll have to design a system that can easily be used and is protected by the elements with a minimal amount of engineering on the part of the owner. Circuit protection and tough insulation are especially important with any marine craft, and the less experienced the sailors, the tougher the better.
As any boat builder can tell you, a boat's wiring is at constant war with the elements. Water alone can corrode wiring, short out improperly insulated or exposed system components, and generally wreak havoc on any electrical system. If your boat is going out on saltwater, you've got the constant attack of salinity to factor in as well. An experienced boat builder knows that parts of a boat which barely see water can still quickly wear out when on the ocean.
While there's no way to completely fight off the sea, your team can limit its ability to cause damage with proper wiring technique. Ensure your electricians only strip enough insulation from any wire to give them the amount they need to crimp a connection. Issue wire crimpers to connect wiring instead of pliers and make sure that a hand-pull test is part of your quality control procedures. Weatherproofing is also essential and should be done with an eye for the worst.
A well-built boat provides peace of mind out on the open ocean.
Most marine electrical systems are built with DC in mind, usually from a battery source or a DC power plant that may be tied to the engine or its own separate plant. AC power on boats is usually provided by an inverter, sometimes installed by the customers as an aftermarket accessory, but more and more often, inverters are coming standard.
Generally, aim for more inverter than your design will need. Inverters are rated by maximum continuous watts, so ask your users what appliances and tools they intend to use while out on the water and choose your inverter accordingly. Make sure, though, that any literature you include with your boat makes clear exactly how much stress the system can take and for how long.
You may also consider wiring certain systems, like the navigation, directly into the inverter. This can be a useful method, especially for limiting exposure to the elements -- just be sure every circuit is properly protected. There's the potential for a surge, and if it blows out the navigation, your customers might be in serious trouble.
Finally, remember that proper wiring starts with the right materials. Get the marine wire & cable, terminals & connectors, and circuit protection before you begin, and you'll have a much better boat.