A plain-English breakdown of how UL 924, NFPA 101, and NEC 700 apply when you use remote heads with a remote-capable unit—what inspectors check, the light-level targets, wiring rules, and the documentation you’ll need. For products, see LED remote head emergency lights; for fundamentals, use the remote head sizing and wiring guide.
Last updated: October 2025
Overview & Key Terms
- Remote head: Low-voltage emergency lamp without a battery; powered by a separate remote-capable unit over a dedicated circuit.
- Unit equipment (host): The battery/charger/transfer device that powers its own lamps and any connected remote heads.
- AHJ: Your local Authority Having Jurisdiction (fire marshal/electrical inspector).
- Goal: Provide code-compliant illumination for 90 minutes, at required light levels, with wiring installed per NEC.
Need fundamentals (sizing, voltage drop, spacing)? See the remote head sizing and wiring guide.
UL 924 — Equipment Listing & Runtime
- Listing: Emergency lights, exit signs, inverters, and combos used for egress lighting should be UL 924 listed for emergency service.
- Runtime: Equipment must support 90 minutes of illumination during a power loss (battery/inverter systems). Transfer to emergency power should occur promptly; field practice aligns with a ~10-second expectation.
- Remote heads: The host’s remote capacity (watts) must cover all connected heads plus its own lamps for the full 90 minutes.
NFPA 101 — Light Levels & Duration
- Minimum egress light: initial average of 1 foot-candle and a minimum of 0.1 foot-candle at any point, with a uniformity ratio ≤ 40:1.
- Duration: Provide emergency illumination for at least 90 minutes after power loss.
- Design note: Verify worst-case points (corners, turns, door landings) meet the average/minimum targets—especially near the end of the 90-minute period.
NEC 700 — Unit Equipment, Circuits & Remote Heads
- Reliability: Plan redundancy so a single lamp failure doesn’t leave a space in total darkness.
- Branch circuits: Emergency lighting circuits supply only emergency loads; identify the emergency branch at the panel.
- Unit equipment wiring: Remote heads not integral to the unit must be wired by approved Chapter 3 methods and per Article 700 routing rules.
- Exterior doors: It’s permitted to power an exterior exit-door remote head from the interior unit equipment serving the area just inside that door—commonly used to light exterior landings at exits.
- Response time: Emergency systems should supply power within roughly 10 seconds of normal power loss.
Documentation & Testing (Monthly / Annual)
- Monthly: Functional test for ~30 seconds (self-test or manual); verify each head illuminates.
- Annual: Full-duration test for 90 minutes; verify illumination levels and that the farthest remote stays bright at the end.
- Records: Keep written logs of dates, results, and corrective actions—ready for AHJ review. Include one-line diagram, head schedule (W & qty), conductor gauge, run lengths, and voltage-drop math.
What Inspectors Look For (Quick Checklist)
- Units and heads are appropriately listed (UL 924) and labeled.
- Light levels meet average/minimum and uniformity along the egress path.
- Runtime demonstrated for 90 minutes; transfer occurs promptly.
- Wiring follows Article 700: correct branch identification, methods, routing, and wet-location practices.
- Remote capacity math documented (host watts ≥ own lamps + all remotes) and voltage compatibility verified.
- Testing logs available and up to date.
Common Pitfalls with Remote Heads
- Mixing voltages (6 V heads on 12/24 V host, or vice versa).
- Exceeding host remote capacity—not enough wattage for 90 minutes.
- Voltage drop on long runs due to undersized conductors; far head dims first.
- Only one light source covering a space—no redundancy if a lamp fails.
- Missing or incomplete test records during inspection.
FAQs About Remote Head Code Requirements
What light levels do I need to show?
Design to an initial average of 1 fc and a minimum of 0.1 fc along the egress path, with a uniformity not exceeding 40:1. Verify at stair doors, turns, and exterior landings near exit doors.
Can I power an exterior head from an interior unit?
Yes—NEC permits a remote head lighting the exterior of an exit door to be supplied by the unit equipment serving the area immediately inside that door, wired by approved methods.
What documentation should I keep?
Monthly 30-second tests and an annual 90-minute test, plus corrective actions. Keep logs available for AHJ review.