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Life Safety Systems — NFPA 72 + UL 464 + CAN/ULC-S524

Audible appliance coverage (UL 464 + NFPA 72 §18.4.4 — signal must exceed ambient by 15 dBA), strobe candela selection from CAN/ULC-S524:2019 Table 42.1, NFPA 72 device spacing, evacuation panel battery + voltage-drop sizing, CEC Section 24 (vital/conditionally-vital/non-vital) and NEC Article 760 routing. Source: EEP Lighting Module (LISP *EEP-LT-HORN-DB*, *EEP-LT-AMBIENT-DB*, *EEP-STROBE-CD-TBL*).

NFPA 72 — 2019 CAN/ULC-S524:2019 CEC 2024 Section 24 NEC 2023 Article 760 UL 464 (Audible) UL 1971 (Visible)
26 horn/speaker models · 28 ambient noise environments · CAN/ULC-S524 Table 42.1 (15 room sizes)

1 Room & Ambient Environment

NFPA 72 §18.4.4 — public-mode audible: signal ≥ avg ambient + 15 dBA OR ≥ max sustained 60 s + 5 dBA, whichever is greater.

2 Audible Appliance Selection

UL 464 listed devices. SPL rating at 10 ft (3 m). Coverage falls 6 dBA per doubling of distance (inverse-square law).

3 Strobe Candela Selection

CAN/ULC-S524:2019 Cl. 42 Table 42.1 (Canadian) — minimum candela rating by max room dimension and strobe arrangement. NFPA 72 §18.5 (US) uses Table 18.5.5.4.1(a).

✓ Audible Coverage Verdict

SPL at design distance must exceed ambient by the margin required for the selected coverage mode.

⚡ Strobe Coverage Verdict

CAN/ULC-S524 Table 42.1 — wall-mount strobe minimum candela by room size + arrangement.

📖 Reference (CAN/ULC-S524 Table 42.1)

Wall-mounted strobe light output requirements. nil = arrangement not allowed for that room size. Values transcribed verbatim from CAN/ULC-S524:2019 Cl. 42, Table 42.1.
NFPA 72 §10.6 Battery Calculation. Standby current × 24 h + alarm current × (5 min for evacuation / 15 min for fire) + 20% safety factor. Sealed lead-acid (SLA) sized at 80% of nameplate for design margin. The full RPT-NFPA-72 export includes battery worksheet, voltage-drop check (max 19% drop on alarm), and SLC/NAC loop integrity.