The W-2PS is a Delay on break timer. At first time, when voltage is applied to the input terminal, the load is energized simultaneously. The time period starts when the power is removed from the W-2PS (due to thermostat, etc), the load will remain de-energized until the delay period has end. At the end of the delay period, the load is energized. The load will remain energized until the input is removed. Preventing rapid re-starting after sudden power loss and use with thermostat controlled equipment.