Journeyman Electrician Exam (NEC)Special Occupancies, Equipment, and ConditionsMedium
A large concert venue, classified as a place of assembly, requires a permanently installed emergency lighting system. How long must the emergency lighting system be able to maintain illumination upon loss of normal power?
- A60 minutes
- B120 minutes
- C90 minutes
- D30 minutes
Show answer & explanationAnswer & explanation
Correct answer: C. 90 minutes
NEC 700.12(B)(2) requires that the emergency lighting system in places of assembly, among other locations, shall be provided with a supply of electricity that, in the event of failure of the normal supply, shall automatically maintain the illumination for a period of at least 1-1/2 hours (90 minutes). This allows for safe egress.
Why the other options are wrong
- A. 60 minutes is not the specified minimum for places of assembly.
- B. 120 minutes exceeds the minimum requirement, but 90 minutes is the NEC specified minimum.
- D. 30 minutes is insufficient for places of assembly.
Emergency Lighting Duration (Assembly)
Emergency lighting systems in places of assembly must be capable of automatically maintaining illumination for a minimum of 90 minutes upon loss of normal power.
- Applies to places of assembly (NEC Article 700).
- Ensures safe egress for occupants.
- Minimum duration is 1.5 hours.
Memory trick: Emergency lights: Enough time for ALL to exit safely.