# To fuse or not



## jwjrw (Jan 14, 2010)

You only need it at one place. If the panel breaker is larger than you need you can fuse it at the disconnect.


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## dronai (Apr 11, 2011)

jwjrw said:


> You only need it at one place. If the panel breaker is larger than you need you can fuse it at the disconnect.


So if the breaker is 2-pole 30A at the CB, but the load at the disco is 11A , fuse it accordingly. 

But if the CB is 2-pole 20A, and the load is 11A, I could go without the fuses right ?

Fuses are probably better for detecting overload conditions than circuit breakers ?


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## jwjrw (Jan 14, 2010)

dronai said:


> So if the breaker is 2-pole 30A at the CB, but the load at the disco is 11A , fuse it accordingly.
> 
> But if the CB is 2-pole 20A, and the load is 11A, I could go without the fuses right ?
> 
> Fuses are probably better for detecting overload conditions than circuit breakers ?



Yep you ca. If the unit specs fuse I use them. Otherwise breakers.


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## stuiec (Sep 25, 2010)

Can you explain this to me? 

As I understand it you are talking about a branch cct protected by a CB with a load (ie fan coil) on it. 

Is it a % of the CB's rated trip that you are using to determine whether or not to fuse (in the given example 55%)?


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## dronai (Apr 11, 2011)

jwjrw said:


> Yep you ca. If the unit specs fuse I use them. Otherwise breakers.


 

Thanks NC ! :thumbsup:


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## dronai (Apr 11, 2011)

stuiec said:


> Can you explain this to me?
> 
> As I understand it you are talking about a branch cct protected by a CB with a load (ie fan coil) on it.
> 
> Is it a % of the CB's rated trip that you are using to determine whether or not to fuse (in the given example 55%)?


I am matching CB to wire size, and fusing to load size. JWJRW explained it above.


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