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Thread: Breaker as On/Off switch
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11-14-2007, 05:16 PM #1
Breaker as On/Off switch
I inspected a detached garage with some finished rooms in the back and above. There was a subpanel in the lower finished area. The lights at the ceiling were fluorescent work lights. The only way to turn them on and off was at the breaker in the subpanel. I have never, ever known a breaker to be the on/off switch for a fixture. So I noted it in my report. An Electrician called me about it (he was fine, didn't have an attitude as some do when talking to Inspectors). He said that since there was another single light with a standard wall switch for this room, it was alright to have the ceiling lights shut off at the breaker.
I thanked him for calling and couldn't wait to get here. I still can't get my head around the fact that it is alright to use a breaker as a standard on/off switch for a fixture. I know that besides the overload protection, a breaker and a light switch are not so different. Anyone else have a thought about that.
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11-14-2007, 05:41 PM #2
Re: Breaker as On/Off switch
This is the best answer I have available:
(From Mike Holt's information)
Electrical Circuit Breakers
Circuit Breakers As Switches
Both the ANSI and the NEC definitions acknowledge the potential for the legitimate use of circuit breakers as switches. Switches (pass, but do not consume electrical power) are considered as being control devices, thus one may also say that a breaker is a control device, or a controller.
To aid in the understanding of a fine point, I offer this comparative example. A gas valve and a steam pressure relief valve are both controllers, one the fuel to the burners that aids in the development steam pressure, and the pressure relief valve that opens on excessive pressure. Both are controllers, one operating (the gas valve) the other safety (the relief valve).
Likewise in a parallel manner; we say that a circuit breaker can control and protect an electrical circuit. An electrical relay is an example of an operating control; it opens and closes the circuit. Circuit breakers are not designed as replacements for relays, operating controls.
There is as you may intuitively have anticipated an exception. Some circuit breakers are manufactured for use in a specific type of application. When a circuit breaker is designed to also be routinely used as an on-off switch to control 277 volt florescent luminaires they are marked SWD, for switch duty. This does not mean that a switch duty breaker can be used to manually control a traffic signal light where it will be cycled 1,000 or more times per day. The point is; the listing for switch duty (SWD) does not mean a circuit breaker can be used as a high frequency cycling operating control, such as a relay that has a life span rated in tens, if not hundreds of thousands of duty cycles.
While circuit breakers can be legitimately and safely used as switches, the frequency and duration of such use is very limited. Routinely circuit breakers are manually operated for service-maintenance, and repair type activities. With the preceding enhancing our understanding; we can say that circuit breakers can legitimately be used as switches, generally they are not intended for prolonged frequent or repetitive manual breaking and making type control of electrical energy utilization equipment.
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11-14-2007, 05:46 PM #3
Re: Breaker as On/Off switch
...circuit breakers can legitimately be used as switches, generally they are not intended for prolonged frequent or repetitive manual breaking and making type control of electrical energy utilization equipment.
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11-14-2007, 05:54 PM #4
Re: Breaker as On/Off switch
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11-14-2007, 07:48 PM #5
Re: Breaker as On/Off switch
Thanks for that link.
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11-14-2007, 08:37 PM #6
Re: Breaker as On/Off switch
I agree with the electrician. The breaker is rated as switch duty so as long as you can safely cut on a light as you enter the space the other lights can be controlled by breaker, motion, or anything thing else.
In my other life, we had 277 volt gym lights that the only switch was the breaker. Not the best situation but legal.
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11-14-2007, 08:49 PM #7
Re: Breaker as On/Off switch
Thannk you everyone. I have a much better understanding. I guess we can end this thread.
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11-14-2007, 09:09 PM #8
Re: Breaker as On/Off switch
In your other life, that was similar to one of the uses described in Mike Holt's information, as to the question which was posed, it is not.
Even in your other life, SWD duty breakers were not really made for use as "switches" like you used them for, but especially in the use in the posted question.
No, SWD (switch duty rated) breakers *are not* "intended" to be used as "switches" - read the information I posted from Mike.
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11-14-2007, 09:23 PM #9
Re: Breaker as On/Off switch
I do not need to read from Mike to quote what I experienced personally. We had over 40 gyms that the lights were controlled only by breakers.
I've used Mike for my CE in the past so he is an old friend.
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11-14-2007, 09:39 PM #10
Re: Breaker as On/Off switch
James,
Likewise, I used to have a 1967 E-Type Jaguar (XKE) and I would drive it really fast for long periods of time (say 130-140 for an hour at a time), it was 'made for that use', but, do you really think that car was designed to be driven that way *ALL THE TIME*?
Nope.
SWD breakers *ARE NOT* intended to be used for that use all the time either.
Going on personal experiences, heck, those old metal case drills were made to be used drilling into fountains with the metal body of the drill down in the water up to the air vents, right? I mean, "what I experienced personally" they were - done it.
Oh, but that's different you say? Actually, no it is not. neither example is different than using SWD breakers for everyday switching duties - NONE of the items was designed or intended to be used that way.
SWD breakers 'could be' used for switches, but 'were not intended to be' used for switches on an everyday use.
My old E-Type 'could be' driven that way, but it 'was not intended to be' driven that way 24/7.
My old metal case drill ... well, it was 'a drill', was it not? And that is what I used it for. (Before GFCI protection came about.)
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11-23-2007, 04:21 PM #11
Re: Breaker as On/Off switch
Breakers can have an additional rating for switching duty, even for HID lighting. Indeed, it has probably bee decades since a breaker was made that did not also have a 'swd' or 'hid' rating. Using them as one would an ordinary switch is not a problem.
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11-23-2007, 04:45 PM #12
Re: Breaker as On/Off switch
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11-30-2007, 12:02 PM #13
Re: Breaker as On/Off switch
Jerry, I go by what UL says on this subject. From their "white book:" "A circuit breaker ... may be marked 'SWD' and is suitable for switching fluorescent lighting loads on a regular basis."
Further, regarding the marking "HID:" "intended to switch HID lighting loads on a regular basis."
The only way I can construe those statements is to say "It's perfectly OK to use the breaker instaed of a switch."
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11-30-2007, 01:28 PM #14
Re: Breaker as On/Off switch
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