Connecting 14ga Romex to 20a circuit?


Old 05-06-20, 10:14 AM
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Connecting 14ga Romex to 20a circuit?

I'm installing two new hard-wired florescent fixtures in a basement.
Can I use 14ga Romex to tie these into an existing 20a rarely used outlet circuit?
Old 05-06-20, 11:09 AM
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That's a big negative. The wiring through the whole circuit needs to be sized to the breaker. 20A breaker requires 12ga wire for the whole run.

An alternative would be to use 14ga wire and swap the breaker with a 15A breaker. Most would recommend adding a note on the wire in the panel that "circuit contains 14ga wire, 15A breaker max" so no one in the future sees the 12ga wire and feels it can be upgraded to 20A.

The concept is that if that florescent fixture has a fault that causes it to draw more power, it could easily pull 18-20A without tripping the breaker, while causing a fire hazard on the 14ga wire rated only to 15A.

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