I recently inspected an apartment complex that has "clips" installed on some breakers in the fuse panel. The breakers are for the smoke detector/fire alarm system. I have done a quick search of NEC, and can not find reference as to if these are allowed or not. The clips prevent you from opening the breaker by hand. They are a bare metal color. A related question- will these "clips" prevent the breaker from tripping in the event of an overload? Lastly- do these have a technical term, I could really use a link to a supplier/product website! Thanks!
Breaker "clips" for fire alarm circuit?
- Thread starter Ikester
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mdshunk
Senior Member
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- Right here.
Re: Breaker "clips" for fire alarm circuit?
I know that the square D part # is QO1LO, but I'm not sure what they're called for sure. They prevent the circuit from being inadvertantly turned off, but the breaker will still trip on a fault. They are often used on emergency lighting circuits, fire and burgalar alarm circuits, etc. I'm not sure what requirement is that they satisfy.
I know that the square D part # is QO1LO, but I'm not sure what they're called for sure. They prevent the circuit from being inadvertantly turned off, but the breaker will still trip on a fault. They are often used on emergency lighting circuits, fire and burgalar alarm circuits, etc. I'm not sure what requirement is that they satisfy.
wanderer20001us
Senior Member
Re: Breaker "clips" for fire alarm circuit?
700.12(F) exception mentions providing a "lock-on" feature to emergency lighting circuits.
Nothing prohibits them as long as the breaker is free to trip. The typical breaker locks allow the breaker to operate during OC/SC conditions but prevent manual operation. Many AHJ's require breaker locks on fire panel circuits, emergency lighting, and other critical circuits that would create hazards if inadvertantly de-energized.
700.12(F) exception mentions providing a "lock-on" feature to emergency lighting circuits.
Nothing prohibits them as long as the breaker is free to trip. The typical breaker locks allow the breaker to operate during OC/SC conditions but prevent manual operation. Many AHJ's require breaker locks on fire panel circuits, emergency lighting, and other critical circuits that would create hazards if inadvertantly de-energized.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Breaker "clips" for fire alarm circuit?
"but the breaker will still trip on a fault"
Circuit breakers are trip free, the internal mechanism can trip if the handle is held on
"but the breaker will still trip on a fault"
Circuit breakers are trip free, the internal mechanism can trip if the handle is held on
Re: Breaker "clips" for fire alarm circuit?
Thanks for the fast responses! I now have you guys bookmarked for any future "situations" I may run across. Tom Baker- I cut and pasted the following from "How Stuff Works", and am not clear on the defs they give vs. the explanation you give. Any feedback on this topic is appreciated.
TRIP-FREE/NONTRIP-FREE CIRCUIT BREAKERS-
From: http://electronics.howstuffworks.com/framed.htm?parent=circuit-breaker.htm&url=http://www.tpub.com/neets/book3/8k.htm
Circuit breakers are classified as being trip free or nontrip free.
A trip-free circuit breaker is a circuit breaker that will trip (open) even if the operating mechanism (ON-OFF switch) is held in the ON position. A nontrip-free circuit breaker can be reset and/or held ON even if an overload or excessive heat condition is present. In other words, a nontrip-free circuit breaker can be bypassed by holding the operating mechanism ON.
Trip-free circuit breakers are used on circuits that cannot tolerate overloads and on nonemergency circuits. Examples of these are precision or current sensitive circuits, nonemergency lighting circuits, and nonessential equipment circuits.
Nontrip-free circuit breakers are used for circuits that are essential for operations. Examples of these circuits are emergency lighting, required control circuits, and essential equipment circuits.
Thanks for the fast responses! I now have you guys bookmarked for any future "situations" I may run across. Tom Baker- I cut and pasted the following from "How Stuff Works", and am not clear on the defs they give vs. the explanation you give. Any feedback on this topic is appreciated.
TRIP-FREE/NONTRIP-FREE CIRCUIT BREAKERS-
From: http://electronics.howstuffworks.com/framed.htm?parent=circuit-breaker.htm&url=http://www.tpub.com/neets/book3/8k.htm
Circuit breakers are classified as being trip free or nontrip free.
A trip-free circuit breaker is a circuit breaker that will trip (open) even if the operating mechanism (ON-OFF switch) is held in the ON position. A nontrip-free circuit breaker can be reset and/or held ON even if an overload or excessive heat condition is present. In other words, a nontrip-free circuit breaker can be bypassed by holding the operating mechanism ON.
Trip-free circuit breakers are used on circuits that cannot tolerate overloads and on nonemergency circuits. Examples of these are precision or current sensitive circuits, nonemergency lighting circuits, and nonessential equipment circuits.
Nontrip-free circuit breakers are used for circuits that are essential for operations. Examples of these circuits are emergency lighting, required control circuits, and essential equipment circuits.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Breaker "clips" for fire alarm circuit?
I took a (not installed) standard QO circuit breaker and held it on, and hit it with my hand, it tripped. At home I have a QO breaker with a clear cover on one side, I'll look at it to see how it can work as trip free.
this may be a UL listing requirement. I looked in the UL white book and did not see a reference to trip free.
I took a (not installed) standard QO circuit breaker and held it on, and hit it with my hand, it tripped. At home I have a QO breaker with a clear cover on one side, I'll look at it to see how it can work as trip free.
this may be a UL listing requirement. I looked in the UL white book and did not see a reference to trip free.
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