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Thread: Occ Sensor Control Wiring in same conduit with 277 volt lighting circuit?

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    Occ Sensor Control Wiring in same conduit with 277 volt lighting circuit?

    I understand that if it's 0-10v dimming circuit, it's considered class 1, and needs to be separate from power conductors....but how about the "low voltage" control conductors going to an occupancy sensor?

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    Sorry....for clarification...I believe the 0-10v dimming conductors are considered class 2 circuits. My previous post said class 1.

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    The LV occupancy sensors that we install are Class 2 so their conductors cannot go in the same raceway as the power conductors. Some 0-10 volt lighting control can be reclassified as Class 1 and occupy the same raceway as the power conductors.
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

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    You can put low voltage wiring in the same condiut as power conductors as long as the low voltage wiring is rated for 600V (i.e. you could use some #14 THHN)

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    Quote Originally Posted by Johnhall30 View Post
    You can put low voltage wiring in the same condiut as power conductors as long as the low voltage wiring is rated for 600V (i.e. you could use some #14 THHN)
    That is not correct.

    -Hal

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    Quote Originally Posted by Johnhall30 View Post
    You can put low voltage wiring in the same condiut as power conductors as long as the low voltage wiring is rated for 600V (i.e. you could use some #14 THHN)

    That's a common misconception, Class 2 circuits that cannot be reclassified as Class 1 cannot be in the same raceway regardless of the voltage rating of the conductors.
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

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    ...unless it's in luminaire cable! I wonder how that is acceptable?

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    Quote Originally Posted by Lbartowski View Post
    ...unless it's in luminaire cable! I wonder how that is acceptable?
    That is acceptable because of the separate jacket around the Class 2 conductors.
    The argument is similar to the argument that two sets of wires, each inside their own EMT or Smurf tube, do not create a violation when those two raceways are run through a common enclosing raceway.

    Sent from my XT1585 using Tapatalk

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    Right, but is luminaire cable really 2 separate raceways just because the control cable is jacketed? That logic would seem to allow me to pull a jacketed control cable (like an 18/3) within an EMT with 277 volt circuits then right?

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    Quote Originally Posted by Lbartowski View Post
    Right, but is luminaire cable really 2 separate raceways just because the control cable is jacketed? That logic would seem to allow me to pull a jacketed control cable (like an 18/3) within an EMT with 277 volt circuits then right?
    Right. If the control cable is a self-contained wiring method that does not require a raceway, it should be able to share the enclosing raceway. But without the explicit UL listing that luminaire cable has, an inspector may not agree.

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