How to Wire the AC on a Boat

Sketch out a drawing where the AC power will enter the boat and where the distribution panel will be located. Include in the drawing the wiring connections and distances between feed and distribution. The more detailed you make the drawing, the easier the remaining steps will be. Consult the electrical manual on proper procedures.

Locate a spot on the exterior of the boat, out of the elements, ideally in the cockpit to install the power inlet assembly. This location should allow easy access to feed the wire cable from the power inlet assembly to the AC distribution panel. Cut a hole in the wall, using a hole saw, just big enough to fit the plug assembly.

Feed a three-wire, 10-gauge, marine-grade cable through the hole for the power inlet assembly to where the AC distribution panel will be located. Leave an extra 6-inch length on both ends for some slack to allow for removal of the power inlet assembly or power distribution panel should it be necessary. Secure the cable with cable clamps held in place with self-tapping screws.

Using a knife, cut back the outer sleeve of the cable about 6 inches, leaving the three wires exposed. Bare the ends using a wire stripper and attach the three wires from the cable to the required connections on the power inlet plug using a screwdriver. Modern cables use black (live), white (neutral) and green (ground) wires and each connection point on the power inlet assembly will be color-coded to match. Using self-tapping screws secure the power inlet assembly to the wall.

Cut out a hole just large enough to install the AC distribution panel at the decided location in the interior of the boat. Normally the panel is near the DC (direct current) distribution panel. Feed the power cable coming from the power inlet assembly through the hole. Cut back the outer sleeve exposing the three wires. Bare a ½ inch of the core on each wire and crimp a ring terminal on each wire.

Connect the black wire to a bus bar that feeds the main circuit breaker on the panel. This breaker in turn feeds power to the remaining circuit breakers. Connect the white wire to the labeled "common" bus bar. Connect the green wire to the bus bar labeled "ground."

Install wall outlets at various locations in the boat. You could use power bars to simplify the wiring while providing several outlets at once. Feed the 12-gauge wiring from each outlet to the AC distribution panel. Attach individual black wires to the output connector of each circuit breaker. Attach the white wires to the "common" bus bar and the green wires to the "ground" bus bar. Press the AC distribution panel into the hole and secure it using the screws that are included with the panel.