How to Rewire a Ballast From 120 to 240

Rewiring a ballast from 120 to 240 volts changes the way its power is delivered. A 120-volt circuit needs three wires to make the connection, while a 240-volt circuit needs four wires to make the same circuit. The extra wire delivers a second branch of 120-volt power. It is important to check that the ballast is rated for 240 service before rewiring. The owner's manual or manufacture website is a good place to confirm this information. Have an electrician run a 240-volt circuit to the light to provide the power.

Noncontact voltage detector
Wire strippers
Pliers
Twist-on wire connectors

Instructions

- 1
  Turn off the power at the electrical distribution panel for the circuit you are working on. Confirm the power is off by touching a noncontact voltage detector to the wire's insulation.
- 2
  Remove the twist-on wire connectors joining the 120-volt supply to the ballast. Pull the wires apart and reinstall the twist-on wire connectors on the 120-volt supply wire's bare ends to protect them. Keep this circuit turned off at the panel.
- 3
  Strip 3/8 inches of insulation off the 240-volt supply wire's four conductors. Loosen the grounding screw in the electrical box. Wrap the green or bare wire around this screw and tighten it down.
- 4
  Twist together the 240 volt's black wire with the black wire from the ballast with pliers. Install a twist-on wire connector on top.
- 5
  Twist together the 240 volt's white wire with the white wire from the ballast with pliers. Install a twist-on wire connector on top.
- 6
  Twist together the 240 volt's red wire with the red or yellow wire from the ballast with pliers. Install a twist-on wire connector on top.

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