How to Wire a Backup Generator System

With a backup generator, you can keep your water pump and various other necessities operating if your power goes out. This could be a life-saving device if you live in the country. A transfer switch is required before you can install this device safely. In the United States, a transfer switch is mandatory, according to the Pacific Gas and Electric Company. The switch disconnects the power from your house and activates the generator. This is necessary to protect repairmen who are working on the power line. The switch also protects your generator if your house's power comes back on when it's running.

Things You'll Need

• Transfer switch
• Electrical cables
• Screwdriver

Instructions

1. Disconnect your home's power at the power box by switching all switches to "off." If you're not sure how to do this, call a licensed electrician.

2. Screw in a transfer switch near the power panel. It can be screwed into the wall or a framed area near the power box. The transfer switch should be double-throw, double-pole capable of managing two 120-volt electrical service cables. The double-pole is required to power two circuits at once. The double-throw is needed because this setup isn't just an on/off switch; it connects an electrical path while the other is disconnected.

3. Disconnect your red and black lines from your panel. Feed them through the knock-out hole at an end of the switch. Feed each through a brass lug near the hole on the panel. Unscrew the lug with your screwdriver. Once the line is through, tighten the lug back up.

4. Feed two additional cables through the knock-out hole in the middle of the generator box. Connect them to the switch by pushing them onto the terminals. Run the same cables to the panel. Attach them onto the brass lugs where the service cables were removed.

5. Feed two other cables through the knock-out hole at the end of your switch. These will go through the opposite side as the ones you just inserted. Attach them to your remaining switch lugs. Connect them to your brass service terminals on the generator.

6. Turn your power back on. This will energize your panel. Flip the switch when you want to use your generator. This will disengage your power lines and switch on the generator.

Tips & Warnings

• Check your area's regulations for the minimum cable gauge size.

• Your area might also restrict installment of these cables by anyone other than a licensed electrician.

• Keep water away from all of the equipment.

References

• Electric Generator Safety: Follow These Guidelines to Make Sure that Your Generator is Working Safely
• City of Columbia, Mo: Safely Installing A Backup Generator
• City of Roseville California: Home Generators