DIY: Automatic Transfer Switch

Automatic transfer switches are used with electric generators to move between the utility's power supply and the generator as needed. This assures the critical electrical systems in your home remain working during an electrical outage. Installing a transfer switch requires some knowledge of safe electrical practices and an understanding of how electricity works. If you lack either of these two skills, contact a qualified technician to make the installation.

Non-contact voltage detector
Level
Drill
Screws
Wire strippers
Screwdriver

Instructions

- 1
  Consult with your local building authority to obtain the necessary permits and learn the local rules for such an installation.
- 2
  Turn off the power to the circuits you are working on at the electrical distribution panel. Confirm the power is off by touching a non-contact voltage detector to the wire's insulation.
- 3
  Remove the screws that fasten the cover on the transfer switch with a screwdriver. Remove the cover and set aside.
- 4
  Hold the transfer switch against the wall and level with a level. Secure to the wall with the drill and screws through the mounting holes and into the wall's framing members. There is typically one hole on each corner of the panel.
- 5
  Run the power wire's from the utility through an access hole in the side of the panel and secure by tightening the compression mechanism with a screwdriver.
- 6
  Strip 3/8 inches of insulation off the end of the three conductors with wire strippers. Insert the black wire into the terminal marker "Utility 1" and tighten it down. Insert the red wire into the terminal marker "Utility 2" and tighten it down. Insert the white wire into the terminal marker "Neutral" and tighten it down. Insert the green or bare wire into the grounding terminal and tighten it down.
- 7
  Run the power wire's from the generator through an access hole in the side of the panel and secure by tightening the compression mechanism.
- 8
  Strip 3/8 inches of insulation off the end of the three conductors with wire strippers. Insert the black wire into the terminal marker "Load 1" and tighten it down. Insert the red wire into the terminal marker "Load 2" and tighten it down. Insert the white wire into the terminal marker "Neutral" and tighten it down. Insert the green or bare wire into the grounding terminal and tighten it down.
- 9
  Run the control wires from the generator through an access hole in the side of the panel. Secure to the panel by tightening the compression mechanism.
- 10
  Consult the owner's manual for the automatic transfer switch and generator to learn what terminals the control wires connect to. Make these connections and tighten the terminals down.
- 11
  Contact your local building authority to inspect your installation before turning the power back on.

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