How to Connect a Reliance Transfer Switch to a Sub-Panel

Identify a location within 18 inches from the home's sub-panel for the transfer switch. Mount the transfer switch to the wall next to the existing load center using the all-purpose screws. Make sure the box is mounted into wood studs, and not simply screwed to the drywall.

Switch off the power in the load center, then remove the cover from the front of the sub-panel, or breaker box. Never work on a home's electrical supply, or on an individual circuit, when the current is still turned on.

Remove a knockout on the bottom of the panel, and connect the wire whip that leads from the transfer switch to this hole. Screw the cable fitting into the hole, and insert the wires into the load center through the knockout hole. Secure the wire whip from the transfer switch into the fitting by tightening the screws on the fitting around the cable.

Identify the circuits you want to power through the transfer switch. In the event of an unexpected power outage, an emergency generator should power key circuits, such as the home's furnace, appliances, essential lighting, etc. The power supplied through the transfer switch will likely not power the entire home, unless you purchase a whole home generator and transfer switch capable of providing the amperage needed to run your entire home.

Examine the wires inserted into the load center that originate from the transfer switch. Connect the green ground wire from the transfer switch to the ground lug in the breaker panel. Connect all the white, neutral wires from the transfer switch to the aluminum neutral lug bar in the load center.

Pick one circuit that you want to power from the transfer switch. Remove the black wire from the breaker that controls this circuit. The red and black wires leading from the Reliance transfer switch are bundled together in pairs, which lead to an individual circuit breaker in the transfer switch. Identify one of the circuit wire bundles. Pick a bundle that connects to a circuit breaker in the transfer switch that is the same rating as the breaker in the home's load center. For example, if the circuit is connected to a 20 amp breaker in the home, make sure to use the same rated breaker in the transfer switch.

Connect the red wire from the transfer switch circuit to the breaker in the home's load center. Connect the black wire from the transfer switch circuit to the wire you removed from the home's circuit breaker. Twist these two wires together and then connect them with a yellow wire nut. Push these wires into the main circuit breaker.

Continue moving the individual key circuits to the transfer switch. Label each circuit on the transfer when the connections are complete. Install the cover back onto the home's main breaker panel when all the connections are complete.