Shielded fire alarm cable

Status
Not open for further replies.
For projects where the fire alarm cabling is not in conduit, are there any specific requirements for cabling to be shielded?
Thanks.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
For projects where the fire alarm cabling is not in conduit, are there any specific requirements for cabling to be shielded?
Thanks.

This is almost exclusively up to the manufacturer. I say "almost" because there might be some municipality somewhere who's decided to stick their nose where it doesn't belong.

It will also depend on whether the cabling is for the signal loop circuit, indicating device circuit, notification appliance circuit, switch loop, or network circuit, and a couple others I may have forgotten.

Please note that when you do use shielded cable, your maximum runs are usually cut in half.
 

luckylerado

Senior Member
Shielded cable is almost exclusively used for audio circuits such as a mass notification or voice evac. Shielding (when done correctly) helps to prevent hissing and popping and other sources of interference from being induced on the speaker coil. I strongly recommend only using shielded cable when necessary and treating it with care when pulling. Yes, you could use it for SLC circuits and normal horn and strobe NAC circuits but it will cause you trouble in the long term with ground faults. I will also add that it is my opinion that shielded cable should not be pulled underslab if it can be avoided for the same reason. There are only a few other rare instances where shielded cable is necessary; like sharing a cable tray with Cat6a, and using it does not necessarily mean a better end product. Most trouble shooting nightmares start with shielded cable.
 
Status
Not open for further replies.
Top