# fire alarm wire - shielded or not?



## 1capybara

Does fire alarm wire always have to be shielded?
Thats what it says in nEC 708.14(1):
"signalling and communications wire shall use shielded twisted pairs."
But I know they sell unshielded FPLR and West Penn Wire
http://www.westpenn-wpw.com/pdfs/fire-alarm-cables.pdf
says shielding is optional:
"OPTIONAL) DEPENDANT ON SYSTEM REQUIREMENTS, AND ENVIRONMENTAL CONDITIONS -
• To protect against interference created from other cables or other
electronic/electrIcal/ Mechanical devices.​• The shield is a 100% Aluminium foiled."
......Also, how do you terminate the shield?
TIA


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## BBQ

1capybara said:


> Does fire alarm wire always have to be shielded?
> Thats what it says in nEC 708.14(1):


Why are you looking in Article 708?

Do you need to be?


> ARTICLE 708
> Critical Operations Power Systems
> (COPS)
> 
> I. General
> 708.1 Scope. The provisions of this article apply to the installation,
> operation, monitoring, control, and maintenance of
> the portions of the premises wiring system intended to supply,
> distribute, and control electricity to designated critical operations
> areas (DCOA) in the event of disruption to elements of
> the normal system.
> 
> Critical operations power systems are those systems so
> classed by municipal, state, federal, or other codes by any
> governmental agency having jurisdiction or by facility engineering
> documentation establishing the necessity for such a
> system. These systems include but are not limited to power
> systems, HVAC, fire alarm, security, communications, and
> signaling for designated critical operations areas.


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## B4T

I have never seen shielded FA wire used anywhere.. it is more of a design mandate than a code.. at least around here..


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## 1capybara

BBQ said:


> Why are you looking in Article 708?
> 
> Do you need to be?


BBQ, your right, I was in the wrong place. thank you, Sir!


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## wildleg

you should always, (ALWAYS), read the FA manual and find out what the manufacturer recommends. they don't recommend shielded if they haven't had com problems. Most manufacturers publish literature on how to terminate (or not) shields and grounds for various installations. What can go wrong = you install miles of FA cable and spend weeks trying to get the Alarm to work, only to find out you installed the wrong cable !


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## 360max

B4T said:


> *I have never seen shielded FA wire *used anywhere.. it is more of a design mandate than a code.. at least around here..



 speaker ckts are normally shielded wire, especially if not run in conduit.


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## BBQ

360max said:


> speaker ckts are normally shielded wire, especially if not run in conduit.


Most manufactures want shielded for the SLC loops as well.


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## user4818

BBQ said:


> Most manufactures want shielded for the SLC loops as well.


I agree, for the big systems. I've never seen a non-addressable or small addressable system that had that requirement.


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## wildleg

B4T said:


> I have never seen shielded FA wire used anywhere.. it is more of a design mandate than a code.. at least around here..


-go into any us gov airplane hangar and you are bound to find flame detectors connected with the lon loop having shielded cable, and the foil and grounds terminated (usually on one end as a drain). 

-Find the natural gas distribution station in your neighborhood, and you will likely find gas detection and flame detection connected to the system with the lon loop having a shielded cable.

I agree about residential systems, but I have used shielded in malls at times.

(I didn't notice if the op specified what kind of systems he was talking about)


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## B4T

wildleg said:


> -go into any us gov airplane hangar and you are bound to find flame detectors connected with the lon loop having shielded cable, and the foil and grounds terminated (usually on one end as a drain).
> 
> -Find the natural gas distribution station in your neighborhood, and you will likely find gas detection and flame detection connected to the system with the lon loop having a shielded cable.
> 
> I agree about residential systems, but I have used shielded in malls at times.
> 
> (I didn't notice if the op specified what kind of systems he was talking about)


I only have experience in residental and small commercial FA systems where the design specifications just have to meet NFPA standards..


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## LARMGUY

wildleg said:


> you should always, (ALWAYS), read the FA manual and find out what the manufacturer recommends. they don't recommend shielded if they haven't had com problems. Most manufacturers publish literature on how to terminate (or not) shields and grounds for various installations. What can go wrong = you install miles of FA cable and spend weeks trying to get the Alarm to work, only to find out you installed the wrong cable !


 
Read, and heed.


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## bduerler

FPLP is what we use


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## 360max

BBQ said:


> Most manufactures want shielded for the SLC loops as well.





bduerler said:


> FPLP is what we use


FPLP just states that it is a fire alarm power limited plenum cable, which can be shielded or non shielded. Most places spec shielded cable for smoke detetor loop, speaker loop, and FA phones.


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## bduerler

360max said:


> FPLP just states that it is a fire alarm power limited plenum cable, which can be shielded or non shielded. Most places spec shielded cable for smoke detetor loop, speaker loop, and FA phones.


ok well shielded for speaker, unshielded for everything else. the AHJ is cool with it and so am I.


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