Where cables are installed within 7 feet of the floor, said cables shall be fastened in an approved manner at intervals of not more than 18 inches. Power-limited fire alarm cables are NOT permitted to be strapped to the exterior of any raceway as a means of support.
Can fire alarm cable be exposed?
Fire alarm cables (Power-Limited) can be installed exposed (not in raceway) as long as it is protected against physical damage. … On most installations, a basic rule of thumb to use is that any fire alarm cable installed above 7 feet can be installed exposed; below 7 feet the cables shall be in a raceway.
Does fire alarm wire have to be in conduit?
According to the National Fire Protection Association (NFPA) regulations and National Electric Code (NEC) articles, any wiring that exists in non-accessible areas or below seven feet must be installed in metallic conduit.
How many fire alarm cables do I need in conduit?
The maximum number of smoke alarms that should be interconnected per NFPA 72 standards is 12.
Why do fire alarm devices have 4 screws?
There are 4 terminals – two terminals are to send alarms in on the zone and two of the terminals are to power the detector.
Can I use Thhn for fire alarm?
THHN and TFN are high-temperature wiring that are approved for fire systems, smoke detectors, and alarms. A contractor, depending on local code, may be able to run groups of single conductors equivalent to the premanufactured FPL type cables.
What would be considered an abandoned fire alarm cable?
There is a definition for Abandoned Fire Alarm Cable in 760.2: “Installed fire alarm cable that is not terminated at equipment other than a connector and not identified for future use with a tag.” Part (A) of 760.3 has the title: “Spread of Fire or Products of Combustion.” The sentence under this title says that …
When two hot wires touch this is called a fault?
Bare wires can inevitably touch the wrong places: Hot wire to neutral wire means a short circuit that causes sparks to fly; hot wire to grounding wire, or to grounded metal box means ground fault and possible shock.
How many types of fire alarm cables are there?
Fire alarm cables are placed into three broad categories: plenum, non-plenum, and riser. Each of these corresponds to another standardized category, and these terms reflect where the fire alarm cable can be installed safely. Plenum cable, to be used in ducts or other enclosed air spaces, is called FPLP.