How do I add new wiring from a junction box

  • New wiring can be tied into a junction box, unless the wiring in the junction box is already at maximum capacity.
  • Before tying in at a junction box, always trace the cables leading to the box to check the voltage. Be sure you are not connecting a 120-volt outlet to a run of wire providing 240 volts for larger appliances.
  • To tie in new wiring at a junction box, first shut off the current at the service panel.
  • Locate the main supply cable coming into the junction box from the service panel. Locate the supply wire by tracing the white wires. All white wires in the junction box will be attached to the white wire on the supply line.
  • Knock out the unused plug on the junction box and run the new line from the box as illustrated (see image). Be sure to use a cable clamp to secure the cable to the junction box.

Check your state and local codes before starting any project. Follow all safety precautions. Every effort has been made to ensure the accuracy and safety of this information. Neither Westlake nor any contributor can be held responsible for damages or injuries resulting from the use of the information in this document.

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