Quick Hits
Quick Hits
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Episode 6: Emergency Illumination and Control (700.15 - 700.28)
The "Total Darkness Prohibition" (700.16(B)) is the gold standard. The system must be designed so that the failure of any single illumination source (like one bulb blowing out) does not leave a required area in total darkness.
System Reliability Features
HID Lighting (700.16(C)): Because High-Intensity Discharge lamps have a "warm-up" period, the emergency system must stay on until the HID reaches full brightness. Use auxiliary LED or Quartz lamps to bridge this gap.
Directly Controlled Luminaires (700.24): If luminaires are dimmed, they must be listed for emergency use and be designed to default to "Full On" during an emergency.
The "So What?" Layer
Understand the Automatic Load Control Relay (ALCR) (700.26). While useful for energizing loads, an ALCR is NOT a transfer switch . It does not have the mechanical interlocks or undergo the rigorous UL 1008 fault-current evaluation required of a transfer switch. Do not use it to switch between two non-synchronous sources.
⚠️ Educational NoticeQuick Hits are educational explanations based on my understanding of the NEC. Always verify requirements in the current adopted NEC, applicable local amendments, manufacturer instructions, and with the AHJ.
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