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Belden Security and Alarm Cables: Fire Alarm Cable Considerations

Belden Security and Alarm Cables: Fire Alarm Cable Considerations

17th Jun 2022

Fire alarm systems are vital components of the architecture of public safety, monitoring the premises for fires and alerting the occupants of buildings to potential fire risks. While they can be activated manually through levers or passively through smoke detectors and other sensors, they must be operable and suitable for the environments in which they are located.

The viability of a fire alarm system begins, of course, with smoke detectors that are properly calibrated and with high-quality fire alarm cables that are rated accordingly.

What Is Fire Alarm Cable?
Unlike heavier, larger gauge building wires, welding cables, and battery cables that are used to provide power to buildings and appliances, fire alarm cables are smaller, multi-conductor cables that are intended to transmit signals around the circuit of a fire alarm system.

However, although they are called fire alarm cables, they actually have many other applications. For instance, and among other Belden security and alarm cables, fire alarm cables can be used for burglar alarms and other security systems, voice communications, and other low voltage applications.

With respect to fire alarm systems themselves, fire alarm cables can be used for a variety of applications. They can be used for damper control, door release, elevator shutdown, and much more.

Fire Alarm Cable Ratings
Fire alarm cables, as you might expect, must be heat and flame-resistant. Cables with a PVC jacket typically produce toxic smoke when heated or burned, so fire alarm cables should be made with insulation that not only self-extinguishes but does not produce toxic smoke or fumes when exposed to high heat.

In addition, fire alarm cables are subjected to three specific important ratings: FPL, FPLR, and FPLP.

FPL, or fire power limited, is a general-purpose rating for fire alarm cables. Cables that carry this rating can be used for general-purpose alarm systems, but should not be used in ducts, plenum or riser space, or elsewhere that experiences airflow from the environment.

FPLR. or fire power limited riser rating, is assigned to cables that are suitable for use in the vertical riser space that spans between the floors of buildings. Because riser space is vertically oriented, riser-rated cables must self-extinguish and should produce little harmful smoke. This helps to keep occupants safe and helps prevent fire from spreading by rising along riser space.

FPLP, or fire power limited plenum rating, is given to cables that are suitable for use in plenum space and air ducts, and in other locations in which there is a high degree of environmental airflow. Plenum space typically occurs in the space above a drop ceiling or beneath a raised floor. Plenum-rated cables should also self-extinguish and should produce little smoke.

Typically, plenum-rated cables are created to more stringent standards than riser-rated cables, making them more expensive. Also, due to the more stringent standards of plenum-rated cables, it is imperative that riser-rated cables never be used in plenum space in lieu of plenum-rated cables.

The best rule of thumb to follow is only to use cables in spaces as required by their standard ratings.

What About Power-Limited and Non-Power Limited Ratings?
One of the common distinctions between fire alarm cables respects whether or not they are power limited.

Power-limited cables are connected to a system that limits the voltage and power supply through the cables. With power-limited cables, the power supply should be one that is specifically listed for use with power limited cables.

Non-power limited cables are less common than power-limited cables and can handle higher voltages.

How Does Wire Gauge Affect Fire Alarm Cable?

                                Belden Security and Alarm Cables

The size of a wire’s gauge will affect its ability to carry a power supply, in this case, an electronic signal. The larger the wire, the less resistance it will offer to the current passing through it. The smaller the wire, the greater the resistance.

Thinner, smaller wires heat up more in response to electrical currents and so are not suitable for high voltage applications. It is also important to note that AWG is an inverse scale. That is, the larger the gauge, the thinner the wire will be.

Fire alarm cables are typically created with anywhere from 2 to 6 conductors and usually range between 18 to 12 AWG. Remember that the resistance of a circuit increases with the length of the cable, so a larger cable might be required for longer runs.

Your Source for Belden Security and Alarm Cables
Do you still have questions about fire alarm or other industry-equivalent Belden security and alarm cables, wire gauge, color-coding, jacket materials, or bare copper conductors?

Across the different specifications, requirements, gauge sizes, and other qualifiers, there’s a lot to take in.

If you still have questions about the different codes or standards applicable to alarm and security cables, get in touch with us by phone or email at 800-262-1598 or at Sales@EWCSWire.com, respectively.