How to Wire Three-Phase Electrical Panels

How to Wire Three-Phase Electrical Panels
Published: Feb 8, 2011
Updated: Nov 20, 2021
1 minute read

Things You Will Need

  • Padlock
  • Flathead screwdriver
  • Megger
  • Three-phase electrical breaker
  • Electrical panel rated for three-phase breakers
  • Wire strippers

Three-phase electrical panels differ from single-phase panels due to the three power leads that are used in three-phase systems.

  1. Shut the main power breaker off at the breaker box, then padlock it to prevent anyone from turning it on while you work on the circuit. (This will only be necessary if you are adding a circuit to a three-phase panel that is already active.) Make sure the panel is rated for three-phase electrical breakers.

  2. Unscrew and remove the breaker panel cover using a flathead screwdriver, then test the main power terminals with a Megger to confirm that the power is turned off.

  3. Install a three-phase breaker into one of the breaker slots using a flathead screwdriver.

  4. Run three wires from the electrical panel to the device you wish to send power to. Strip the ends of the wires using wire strippers, then insert each of the three wires into one of the three breaker lugs and terminate them using a flathead screwdriver. No neutral wire is needed.

  5. Run a ground wire from the panel to the electrical device. Strip the end of the wire using wire strippers, then terminate the wire on the panel’s grounding bar using a flathead screwdriver. Repeat the same process for additional circuits.

  6. Reinstall the panel cover using a flathead screwdriver. The panel is now wired. Terminate all circuits into their termination points on the electrical devices, and test the circuits and devices with a Megger before restoring power.

Photo Credits

electrical panel switch image by jimcox40 from Fotolia.com

electrical panel switch image by jimcox40 from Fotolia.com

Eric W. Thompson

Eric W. Thompson began his writing career in 1996 and is now a member of the All-USA Academic Team, having been featured in "USA Today" as one of the top 20 community college students in the country. He is currently taking a break from…

Sponsored
HomeSteady Logo

HomeSteady is the ultimate guide for all your household needs, from cleaning and HVAC to electrical, DIY and maintenance.

Property of TechnologyAdvice. © 2026 TechnologyAdvice. All Rights Reserved

Advertiser Disclosure: Some of the products that appear on this site are from companies from which TechnologyAdvice receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. TechnologyAdvice does not include all companies or all types of products available in the marketplace.