Starting device and circuit for starting single phase motors

A method for starting a permanent split capacitor motor having a start winding and a run winding through an auxiliary starting circuit comprising the steps of;

• electrically connecting an auxiliary start capacitor and the normally closed contacts of a control relay in series,
• electrically connecting the coil of said control relay in series with a resistor and connecting said series connected coil and resistor in parallel with said series connected auxiliary start capacitor and normally closed contacts for sensing voltage,
• electrically connecting said series connected auxiliary start capacitor and normally closed contacts said series connected control relay coil and resistor in parallel with the start and run windings of the motor, and
• applying electrical power to the common and run terminals of the motor, whereby
• said control relay coil means becomes energized upon detection of voltage representing full motor speed to open said normally closed contacts and disconnect the electrical connection between said auxiliary start capacitor and the start and run windings, and
• said control relay coil becomes de-energized upon detection of no voltage to close said normally closed contacts and reconnect said auxiliary start capacitor to allow the immediate re-application of electrical power to the common and run terminals of the motor for starting the motor through the auxiliary start circuit.

An auxiliary starting device adapted to be connected by only two interchangeable wires to a permanent split capacitor motor having a start winding and a run winding, the device comprising;

• an auxiliary start capacitor and relay means including a set of normally closed contacts, a control relay coil, and a resistor,
• said auxiliary start capacitor and said normally closed contacts electrically connected in series with one another, said control relay coil and said resistor electrically connected in series with one another and connected in parallel with said series connected auxiliary start capacitor and said normally closed contacts,
• one element of said normally closed contacts being connected to a first terminal, said auxiliary start capacitor being connected in series between another element of said normally closed contacts and a second terminal, and said series connected control relay coil and resistor being connected between said first terminal and said second terminal and coupled with said normally closed contacts to open said contacts upon a predetermined voltage representing full motor speed,
• a first non-polarized wire lead having one end connected to said first terminal and a second non-polarized wire lead having one end connected to said second terminal, and
• the free ends of said non-polarized wire leads adapted to be interchangeably electrically connected in parallel with the start and run windings of the motor, whereby
• said control relay coil becomes energized upon detection of voltage representing full motor speed to open said normally closed contacts and disconnect the electrical connection between said auxiliary start capacitor and the start and run windings, and
• said control relay coil becomes de-energized upon detection of no voltage to close said normally closed contacts and reconnect said auxiliary start capacitor to allow the immediate re-application of electrical power to the common and start terminals of the motor for starting the motor through the auxiliary start circuit.