AC Electric Systems
The 240-volt AC system circuit starts at the consumer box on the boat, where it is supplied by either the shore supply or the boat's generator (AC1 or AC2) or through an inverter from the boat's battery bank.
A circuit breaker should be fitted on each outlet from the consumer box, the same as on a domestic consumer box. On a boat, it is wise to have the 240-volt AC cabling in a different colour to the DC cable runs; keep the AC runs in blue and DC in white or black, or vis versa.
Inverter/chargers today are a powerful addition to the electrical system, as a sine inverter and battery charger with automatic switching, linked to a BMV (battery monitor) and a multi-control panel; its the complete system, with adaptive 4-stage charging characteristics: bulk-absorption-floatstorage. To complete the system, an Isolation Transformer and a Solar Panel plus a good set of batteries, and that's the boat electrics sorted for a few years.
DC Electric - 12 & 24 Volt
There are generally four master switches to isolate the main electric DC circuits on a boat.
1. Domestic Supply 2. Generator 3. Batteries 4. Controller.
The DC master switches are generally located near the battery bank.
A typical battery bank to supply DC current, is 3 x 220 amp batteries for the domestic services and one 180 amp battery for engine starting.
Solar panels are becoming more popular on boats as they act as a constant and free charging facility during daylight hours.
For instance, a single panel of 350watts will keep two domestic fridges (the new efficient ones) going without backup power. Boaters are now finding that by having solar panels with LED lights and economic power systems, they are very rarely using their generators.
One of our member's generators is still in its winterised condition after five years. New solar panels now have the option of having a controller that will send your mobile phone an instant display of charge currents.