Time delayed shut-down circuit for recirculation pump

A circuit for controlling the application of electrical power to a pump motor, comprising

• a plurality of electrical conductors adapted to be connected to an electrical pump motor for applying electrical power thereto,
• a first relay having a pair of cooperating contacts in at least one of said conductors for controlling the flow of current therethrough,
• a second relay having a coil connected between two of said conductors, said second relay thereby being actuated upon the application of an electrical potential between said two conductors,
• one end of the coil of said first relay being connected to a first of said two conductors and the other end thereof being connected to a first fixed contact of said second relay, said other end of said coil of said first relay also being connected to a second fixed contact of said second relay through a pressure-sensitive switch adapted to sense the output pressure of a pump driven by such motor, said pressure-sensitive switch being adapted to open and interrupt the connection between said first relay coil and said second fixed contact of said second relay for sensed pressures less than a predetermined minimum, and
• a movable contact on said second relay connected to a second of said two conductors and contacting said first fixed contact when said second relay is first actuated, said second relay being adapted to return to a de-energized condition upon the expiration of a predetermined period of time, moving said movable contact into contact with said second fixed contact,
• whereby energization of an associated pump motor is assured for a predetermined period of time irrespective of the output pressure of the associated pump, after which period of time the pump motor will be de-energized when such output pressure drops below a predetermined level.