
While these cordsets can handle lots more amperage than the conventional 30A cords, it’s also common to find some boats using two 30A cordsets. Larger boats can satisfy their need for more power using a 50A 125V or a 50A 125/250V cordset, assuming that your marina provides 50A service. The contacts on the plug will only fit one way into the receptacle, which prevents polarity problems and also provides a secure connection when the plug is twisted slightly clockwise. The ideal companion to this outlet is a 30A, 50' cord, by far the most common cord in the U.S. These receptacles have a threaded ring that allows the shore power cord to connect securely and make a waterproof connection. The conventional system used by mid-sized boats in your local marina combines two circuits with circuit breakers rated at 30A, two female receptacles, and a hinged lid to keep water off the connection.

Your shore power system starts at the dock power pedestal. Others include dehumidifiers, heaters, kitchen appliances, power tools, and entertainment products like TVs and stereos. One of the most common devices is a battery charger to keep your batteries topped off when you’re not onboard. Your shore power system allows you to run all sorts of useful appliances and tools on board when you’re in a marina.

#30 amp shore power plug generator
While shorepower systems only work when you are plugged in to an external source of AC power at the dock, many boats create their own AC power away from the dock with a generator or an inverter-either of which enables you to enjoy AC power when underway. Shown above is a typical single phase 120-volt system with shore-grounded (White) neutral conductor and grounding (green) conductor (see ABYC Standards E-11.17.1. You literally plug your boat into the local utility and enjoy all of the advantages onboard that you’d enjoy in your home or business.

A second electrical system, your shore power system, allows you to bring AC electricity onboard from a source on the dock. Your boat’s DC system most likely operates on either 12V or 24V, from energy stored in the boat’s batteries which are replenished by the boat’s charging system. Most boats have a DC electrical system, so you can start your engine or engines, operate interior lights, pump your bilge and operate marine electronics.
