Fire alarm batteries and fuses

[daleh]

Can someone help me out? Does it say anywhere that fire alarm systems with batteries in a remote battery box require over current protection at the battery?

In most panels with internal batteries, the short wire run is not fused. Some fire alarm system battery boxes have fuses or circuit breakers, while others do not. There can be several feet of unprotected wired subject to a direct short across a high current battery.

Looking in NFPA 70 2002 (I don't have a newer copy handy right now) Article 760.24 states over current protection shall be located at the source. I read that to mean a fuse or breaker at the battery. If that's true, why don't most panels have a fuse when the batteries are in the same cabinet as the alarm panel?

 

[barbeer]

I have a feeling they are referring to the line voltage side of the circuit. I have in fact seen fuses installed on the PCB of a fire panel, at least, if you are concerned use an in-line fuse.

 

[daleh]

Thanks for responding. Actually there are several other circuits besides the line voltage that are non-powerlimited that the code might be referring to also. I understand I can use an inline fuse, I'm just trying figure out the requirement. Seems like I read somewhere of a distance requirement before you needed a fuse. I've been doing this for over 15 years and every now and then I have a hard time finding something like this that I thought would be easy to find.

 

[pye]

From what a AHJ once told me. it ment that there should be a breaker or fuse in the box that contains the batteries, so if you have remote batteries in another panel feeding another panel the limiting device should be in the panel with the batteries. For me there was no clear statement to that in the code.