What is the industry standard for most fire alarm cable?

• A. Solid wire
• B. Stranded wire
• C. Coaxial cable
• D. Fiber optic cable

Answer: (A)

In most building alarm installations, the wiring is fixed wiring installed in walls and conduits, so solid copper conductors are the standard for fire alarm cable. Solid wire provides stable, long-run electrical characteristics and clean, reliable terminations at panels and devices. It’s less prone to the loose-terminals and fatigue issues that can come with stranded conductors in fixed installations, and it’s cost-effective for the large amounts of wiring used in alarm systems.

Stranded wire is reserved for applications that require genuine flexibility, such as cables that move or bend frequently. Coaxial and fiber optic cables serve different purposes—coaxial is older for video or certain signaling in some setups, and fiber optic is used for high-bandwidth, long-distance communications or EMI immunity—not the typical choice for the majority of fire alarm cabling.