What’s the difference between power limited cables and non-power limited cables?

The difference between power limited cables and non-power limited cables comes down to which sections of NEC they comply with. Non-power limited cables is a fire alarm circuit powered by a source that complies with NEC sections 760-21 and 760-23. Power limited cables is a fire alarm circuit powered by a source that complies with section 760-41.

Generally, how do I know what kind of fire alarm cable I need?

Fire alarm cables are placed into three broad categories: plenum, non-plenum, and riser. Each of these corresponds to another standardized category. Plenum cable, to be used in ducts or other enclosed air spaces, is called FPLP; non-plenum cable, to be used in applications such as surface wiring, is FPL; and riser cable, which can be used in applications that go vertically from floor to floor, is FPLR. All of these names reflect where the fire alarm cable can be installed safely. Once you know where you will install the cable, you know in which category to start looking.

What are some important safety precautions to consider when choosing fire alarm cable?

There are many safety precautions such as voltage, abrasion resistance, chemical resistance, etc., that should be considered in choosing any kind of electrical cable, including that for fire alarms. However, there are some notable fire-related safety precautions to consider as well. First is the fire resistance of the cable – will it burn and/or how long will it burn? Another is smoke propagation — how much will it give off if it comes in contact with fire? These considerations should be made when choosing any type of electrical cable, but they are especially important in the case of fire alarm cable which must function in emergency situations and under extreme conditions.

Most safety concerns (including these fire-related ones) are regulated by the UL, NEC, and other standards organizations and guidelines. The NEC outlines acceptable limits for burning and smoke emissions while the UL and other organizations are responsible for the development of various flame tests cables must pass in order to be considered safe for use.

This article comes from awcwire edit released