Power supply apparatus

A power supply apparatus including a single movable contact which is provided on an output line from a power supply unit to an output terminal for providing electric power to a load and shuts down the output line, a tripping coil which moves the single movable contact to a shutdown position of the output line, and a manual operating unit which directly manually moves the single movable contact from the shutdown position to a connection position, the power supply apparatus comprising:

• an electrical leak detection current transformer which is provided on a side of the output terminal from the single movable contact;
• a drive circuit which energizes the tripping coil for a predetermined time in order to move the single movable contact to the shutdown position in response to an electrical leak current detection signal outputted from the current transformer;
• a returning means for inputting a reset signal to the drive circuit when the single movable contact is directly manually returned from the shutdown position to the connection position, said returning means is configured to be powered by a power from said power supply unit which is taken out on the output terminal of the single movable contact side located upstream from said electrical leak detection current transformer, and
• a non-contact signal-transmission unit is provided on a signal transmission path of the returning means to electrically insulate said signal transmission path from said power supply unit, wherein the drive circuit is powered by a power supply which is taken out on the side of the power supply unit upstream from the single movable contact.