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) who interprets and enforces codes.
- Goal: Provide code-compliant illumination for 90 minutes, at the 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 must occur rapidly (industry practice aligns with the 10-second benchmark for emergency systems).
- Implication for 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 light levels on the egress path: initial average of 1 foot-candle and a minimum of 0.1 foot-candle at any point, with a uniformity ratio not exceeding 40:1.
- Duration: Provide emergency illumination for at least 90 minutes after power loss.
- Design note: For remote heads, 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: NEC requires designs so a single lamp failure won’t leave a space in total darkness—plan redundancy (e.g., more than one head/light source serving an area).
- 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 wiring 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 must supply power to emergency loads 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, corrective actions—ready for AHJ review.
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, supervision where applicable.
- Remote capacity math documented (host watts ≥ own lamps + all remotes).
- Testing logs (monthly/annual) available and up to date.
Common Pitfalls with Remote Heads
- Mixing voltages (6V heads on 12V 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.