Are the rules for control wiring in a lighting controller the same as for a motor controller?what I'm asking is,can #16 or #14 thhn stranded or machine tool wiring be used for the control wiring to relays or contactors coils that do not carry the actual load current in a lighting controller or ansul shutdown controller as long as the control wiring does not leave the enclosure?The control for most of these devices are drawn tapping off of a 20 amp lighting circuit (#12wire) that is on the line side of the contactor or if smaller control wiring is used does a smaller control fuse need to be installed to protect the control wiring itself?does the control wiring need to stay #12 since it is on a 20a circuit breaker?
Lighting controller
- Thread starter jap2525
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Re: Lighting controller
No, I don't think the same rules apply. Motors and motor controllers are covered in article 430. That article doesn't cover anything except motor and motor circuits.
Your best bet at reducing wire size is article 725. But you will have to determine what "Class" your power source is. And I think you have to provide a smaller fuse to protect the conductors (see 725.23 for example).
In general, the article 240 tap rules don't apply to branch circuits, so you can't use those to eliminate the fuse.
Steve
No, I don't think the same rules apply. Motors and motor controllers are covered in article 430. That article doesn't cover anything except motor and motor circuits.
Your best bet at reducing wire size is article 725. But you will have to determine what "Class" your power source is. And I think you have to provide a smaller fuse to protect the conductors (see 725.23 for example).
In general, the article 240 tap rules don't apply to branch circuits, so you can't use those to eliminate the fuse.
Steve
Re: Lighting controller
You are welcome.
Two things that wire sizes have to comply with are overcurrent protection, and minimum wire size.
You can also refer to table 240.3 and paragraph 310.5 to see if your application fits any of the other catagories listed. For example, the ansul system may fit the "fire alarm catagory" in 310.5 exception #7.
Steve
You are welcome.
Two things that wire sizes have to comply with are overcurrent protection, and minimum wire size.
You can also refer to table 240.3 and paragraph 310.5 to see if your application fits any of the other catagories listed. For example, the ansul system may fit the "fire alarm catagory" in 310.5 exception #7.
Steve
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Re: Lighting controller
You can use smaller conductors then 14 AWG on class one control circuits but not protected by the 20 amp breaker add a fuse in the enclosure housing your lighting controller.
You can use smaller conductors then 14 AWG on class one control circuits but not protected by the 20 amp breaker add a fuse in the enclosure housing your lighting controller.
Do not choose a wire so small that the fuse for it can not handle the inrush of any coils you may have.
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