The Model 553-01 Re-Acceleration Relay is designed to take the place of a voltage sensing relay and two time delay relays. When voltage is applied to the Model 553-01, and the external start switch is closed, the adjustable on-delay time begins. After the delay period, the contacts will close. If the line voltage drops below 90 volts, the contacts open and the true-off delay begins. If the voltage rises above 105 volts before the true-off delay has elapsed, the contact will re-close. If voltage is not restored to 105 volts before the true-off delay time period ends, the contacts will remain open until the external start switch is closed.