National Electrical Installation Standards

Standards as High as Your Own

 
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Friday, October 27, 2006

Question:

Are spare conduits required from panelboards into the attic for future use? The company I work for currently installs them for any additional circuits the homeowner might like to add at a later date, or in case the contractor missed a branch circuit feeder on rough. I haven’t seen any information in the NEC. Roger
A

Answer:

It depends on the wiring method being used. If you are using a raceway method, it's a good idea to provide easy access to a flush-mounted panel for future electrical expansion by providing spare conduits into the attic. If you are using a cable system, such as NM cable, NEC 312.5(C) requires each cable to be secured to the panel. Providing spare conduits to a junction box in the attic where you could attach cables and then run the necessary conductors through the conduit into the panel is a viable option if you maintain the accessibility of the junction box. Remember to close up the spare conduit entries if you don’t provide a junction box at this time. NEC 90.8 recommends (but doesn't require) installing spare raceways and leaving additional panelboard spaces for future use.

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