Pathway Survivability Calculator

Determine NFPA 72 pathway survivability class and protection requirements for fire alarm circuits.

Input Parameters

Results

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Required Fire Rating
hours
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Total Cable Length
ft
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Conduit/Protection
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Survivability Level
Note: NFPA 72 Ch. 12 defines pathway survivability classes. High-rise buildings, healthcare, and mass notification systems typically require Class 2 or 3. CI cable or MI cable can eliminate need for rated enclosures.

Reference

NFPA 72 Section 12.4 Pathway Survivability: Class 0: No survivability requirement Class 1: Pathways protected for 1 hour Class 2: Pathways protected for 2 hours Class 3: 2-hour protection + performance verification Total Cable = Path Length x Circuits x 1.1 (waste factor)