On and off trippers are used to set the clock. Set them for the desired times, and the clock will control the flow of electricity to a specific piece of machinery. To set the clock, you simply pull the face toward you and rotate it until the number on the dial, corresponding to the correct time of day, is under the time pointer. After setting the correct time, release the dial and it snaps back into position, re-engaging its drive gear with the motor drive gear. Screw terminals are located at the bottom of the clock so it can be attached to the wires of the appliance like motors, light, fixtures.
Electricity flows into the clock from a household circuit breaker.
This way there is a constant supply of electricity to the clock. Waterproof boxes in metal or plastic are available to house time clocks. Other versions have built-in brackets that are designed to align with the screw holes on the clock plate, and these are held in place by two machine screws. The boxes are built with knock-out holes to accommodate wiring conduit of various sizes and have predrilled holes in the back for mounting the box to a wall. Only care should be taken to remember that whenever the heater is on, the pump timer must be set to shut off at least half an hour later.