Phase sequence switching device for three-phase power supply

摘要

A phase sequence switching device for a three-phase power supply is disposed in a power supply path from a three-phase power supply (1) to a load (2) and includes a power-supply side relay (7, 11) including two Form C contact relays (7a, 7b, 11b 11c) connected to two phases of the three-phase power supply (1) respectively, a load side relay (8, 12) including two Form C contact relays (8a, 8b, 12b, 12c) connected between the power-supply side relay (7, 11) and the load (2), and a switching circuit (9, 13) connected between the power-supply side relay (7, 11) and the load side relay (8, 12) and wired to be capable of switching by a relay action between a state where the three-phase power supply (1) is connected to a positive phase so that power is supplied to the load (2) side and a state where the three-phase power supply (1) is connected to a reverse phase so that power is supplied to the load (2) side.