Current limiting breaker sizing

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Trickyflea

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Do I size a current limiting breaker using the same 125%/80% rule as a normal breaker? I have track lighting that I need to limit at 4 amps. Do I use a 4 amp current limiting breaker, or 125% of load, 5 amp?
 
Size it the same. The "current limiting" part, just like with current limiting fuses, just means that it will only allow a certain amount of current to flow under a faulted condition before quickly tripping. It has nothing to do with limiting the normal operating current.
 
Size it the same. The "current limiting" part, just like with current limiting fuses, just means that it will only allow a certain amount of current to flow under a faulted condition before quickly tripping. It has nothing to do with limiting the normal operating current.
Actually it does have to do with that. These are devices that are required by some energy codes to limit the amount of power that can be used on the track lighting. They are often available as part of the power feed connector to the track.
These have nothing to do with fault current.
 
Perhaps we need to define what the OP is talking about.

@Trickyflea - can you post a picture, part number, or link to what you're describing?
 
Something like these, I think:


Cheers, Wayne
I didn't realize they actually referred to those as current limiting circuit breakers. It's a semantics thing, but I had heard of them as current limiting devices, similar to current limited power supplies for example. When I hear current limiting circuit breaker, I think of limiting peak let-through for fault conditions. This certainly could have been my mistake on my answer on assuming a different terminology being used.
 
I didn't realize they actually referred to those as current limiting circuit breakers.
I think the word breaker in the OP was imprecise. But as it mentions track lighting, it must mean current limiting devices, not something fancier.

Cheers, Wayne
 
Do I size a current limiting breaker using the same 125%/80% rule as a normal breaker? I have track lighting that I need to limit at 4 amps. Do I use a 4 amp current limiting breaker, or 125% of load, 5 amp?
What I am doing is trying to bypass using a current limiting panel (see link) that is spec'd...(70 days out, client needs to move in in two weeks) with some devices/breakers. https://www.acuitybrands.com/produc...lverbullet/sub-branch-circuit-current-limiter
 
What I am doing is trying to bypass using a current limiting panel (see link) that is spec'd...(70 days out, client needs to move in in two weeks) with some devices/breakers. https://www.acuitybrands.com/produc...lverbullet/sub-branch-circuit-current-limiter
Yeah, so those are not "current limiting circuit breakers" in the sense that bwat was initially referring to, those are "current limiters" specific to these track lighting systems. The Juno devices that wwhitney posted later seem to be an alternative, but you would need to check to see if your track lighting system needs a specific current limiter per their UL listing.
 
Yeah, so those are not "current limiting circuit breakers" in the sense that bwat was initially referring to, those are "current limiters" specific to these track lighting systems. The Juno devices that bwat posted later seem to be an alternative, but you would need to check to see if your track lighting system needs a specific current limiter per their UL listing.
Jraef, Do you know of any devices that I could purchase and install on din rails in a large screw cover box and run these two circuits through? I am just trying to satisfy the energy code.
 
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