How to Hook Up a GE In-Wall Timer

Flip the circuit breaker controlling the electrical circuit that the GE in-wall timer operates to the "Off" position. The circuit breaker mounts in the building's electric service panel. The service panel's identification chart labels each circuit breaker and the room it serves. If the service panel does not contain circuit breaker labels, turn off all of the circuit breakers.

Remove the old wall switch, if necessary. Loosen the old wall switch's mounting screws, using a slotted screwdriver to turn the screws counterclockwise. Pull the old switch out of the switch box and cut the two black-colored wires that wrap around the switch's wire terminal screws with wire cutters.

Pull the ends of both wire sets out of the wall-mount electric switch box. The switch box contains two wire sets. One wire set, called the "Line," runs to the circuit breaker. The other wire set, called the "Load," connects to the appliance the in-wall timer controls. Each wire set contains a black insulated wire strand, a white insulated wire strand and an uninsulated wire strand.

Remove one-half inch of the insulation from the end of each wire set's strands, using wire strippers to peel the insulation off.

Identify the Line and Load wire sets in the switch box. Often, the electrician who originally installed the wire sets wraps a piece of electrical tape around the Line wire set. If not, turn on the switch box's circuit breaker. Carefully touch the ends of a wire set's insulated wires with a volt meter's probes. If the volt meter reads about 120 volts, consider that wire set "Line." If the volt meter reads zero volts, consider that wire set "Load." Turn off the circuit breaker.

Combine the two uninsulated wires in the switch box with the GE in-wall timer's green-colored wire lead. Spin a wire nut clockwise over the wire ends to tighten and hold them together.

Twist the GE in-wall timer's black-colored wire lead around the Line wire set's black-colored wire. Spin a wire nut clockwise over the wire ends. A GE in-wall timer uses the black wire lead to energize the electronic timer and as a power source for the timer's load circuit.

Join the two white-colored wires in the switch box with the GE in-wall timer's white-colored wire lead and tighten a wire nut over the ends. The white-colored wires connect to the neutral part of the electric circuit. A GE in-wall timer's white wire completes the timer's electronic timer circuit. Switches without a timer do not connect to the white-colored neutral wire.

Wrap the GE in-wall timer's red-colored wire lead around the Load wire set's black-colored wire. Tighten a wire nut over the ends. A GE in-wall timer delivers electricity to the load circuit through the red-colored wire.

Push the wire nuts holding the in-wall timer's wire leads and the wire set's wires together into the switch box.

Insert the GE in-wall timer into the switch box. Align the screw holes in the timer's mounting tabs, located on the top and bottom of the timer, with the switch box's screw holes.

Run a GE-supplied mounting screw through the timer's top screw hole and into the switch box's top screw hole. Tighten the mounting screw, using a slotted screwdriver to turn the mounting screw clockwise. Repeat this procedure with the bottom mounting screw.

Position the timer's cover plate over the in-wall timer and tighten the timer's two mounting screws, using the slotted screwdriver to turn the screws clockwise.