Journeyman Electrician Exam (NEC)Special Occupancies, Equipment, and ConditionsEasy
A newly installed emergency lighting system in a hospital operating room must be supplied by an emergency power source. According to the NEC, what is the maximum time allowed for the emergency power source to supply illumination and power upon failure of the normal supply?
- A60 seconds
- B5 seconds
- C10 seconds
- D15 seconds
Show answer & explanationAnswer & explanation
Correct answer: C. 10 seconds
For emergency systems in health care facilities, the NEC requires that the emergency power supply must be capable of supplying illumination and power within 10 seconds of normal power failure. This ensures critical systems remain operational with minimal interruption.
Why the other options are wrong
- A. This is significantly longer than the NEC requirement for emergency power restoration in critical health care settings.
- B. This is too fast for the general requirement for emergency systems in health care facilities.
- D. This duration exceeds the maximum allowable time for emergency power restoration in health care facilities.
Emergency System Transfer Time (Healthcare)
The maximum permissible time for an emergency power system to activate and supply power to critical loads in a healthcare facility after the normal power supply fails.
- Applies to emergency systems in healthcare facilities.
- Ensures continuous operation of life-safety and critical equipment.
- Mandated by NEC to be within 10 seconds.
Memory trick: Ten seconds to save lives in a hospital emergency.