Transfer Switches

Switching between power sources safely

A transfer switch prevents two power sources, typically shore power and a generator, or two shore connections, from being connected to the same circuit at once, which matters because feeding a boat's AC system from two live sources simultaneously can damage equipment and creates a genuine safety risk. Manual switches rely on the operator to select the correct source before connecting the other; automatic changeover units sense when a source is live and switch without intervention, which suits boats that run a generator unattended or want a seamless handover.

Rating is the key check before choosing one: the switch needs a current rating that covers the boat's full AC load, not just what is typically drawn, and the number of poles needs to match whether you are switching a single live conductor or both live and neutral. Wiring work of this kind is worth having checked by a qualified marine electrician if you are not confident with shore power systems, given the safety consequences of a wiring mistake.