Which might be used to satisfy survivability requirements?

Which might be used to satisfy survivability requirements?

• A. 2-hour rated CI cable
• B. 2-hour rated enclosure
• C. Metal raceways in fully-sprinklered buildings
• D. 4-hour rated enclosure

Answer: (A)

Survivability requirements aim to keep the fire alarm system operable during a fire for a defined period. The best way to meet this is to use wiring that itself is rated to withstand fire for that duration, so the signaling remains intact even as the surroundings burn. A two-hour rated CI cable provides that level of fire resistance for the conductors and insulation, directly ensuring the circuit can survive the fire long enough to maintain system operation. Using a two-hour rated enclosure would protect the equipment inside, but it doesn’t guarantee the cabling or the circuits remain functional throughout the fire. A four-hour enclosure goes beyond what’s typically required and isn’t the standard method for meeting survivability. Metal raceways add physical protection, but they don’t set the necessary fire-resistance rating for the conductors or guarantee continued operation during a fire.

Survivability requirements aim to keep the fire alarm system operable during a fire for a defined period. The best way to meet this is to use wiring that itself is rated to withstand fire for that duration, so the signaling remains intact even as the surroundings burn. A two-hour rated CI cable provides that level of fire resistance for the conductors and insulation, directly ensuring the circuit can survive the fire long enough to maintain system operation.

Using a two-hour rated enclosure would protect the equipment inside, but it doesn’t guarantee the cabling or the circuits remain functional throughout the fire. A four-hour enclosure goes beyond what’s typically required and isn’t the standard method for meeting survivability. Metal raceways add physical protection, but they don’t set the necessary fire-resistance rating for the conductors or guarantee continued operation during a fire.