CEI Emergency & Standby Systems 3 — Questions and Answers
Question 1: NEC 700.3 requires emergency systems to be tested under load at what minimum frequency?
- Monthly for 30 minutes (Correct answer)
- Quarterly for 1 hour
- Annually for 2 hours
- Bi-annually for 4 hours
Correct answer: Monthly for 30 minutes
NEC 700.3(B) requires emergency systems to be tested under load conditions at least monthly for a minimum of 30 minutes.
Question 2: Which of the following loads is classified as an emergency system load under NEC Article 700?
- HVAC for comfort cooling
- Exit signs and egress lighting (Correct answer)
- Elevators for general use
- Office equipment circuits
Correct answer: Exit signs and egress lighting
Exit signs and egress lighting are classic life-safety loads assigned to the emergency system under NEC Article 700.
Question 3: What is the maximum allowable voltage drop on emergency system branch circuits under NEC 700.10?
- 2%
- 3%
- 5%
- No specific limit is stated (Correct answer)
Correct answer: No specific limit is stated
NEC Article 700 does not specify a maximum voltage drop for emergency circuits, though good practice and NFPA 110 recommend limiting drop to ensure reliable operation.
Question 4: An optional standby system is covered by which NEC article?
- Article 700
- Article 701
- Article 702 (Correct answer)
- Article 445
Correct answer: Article 702
NEC Article 702 covers optional standby systems, which protect private business operations but are not required by law for life safety.
Question 5: A sign reading 'EMERGENCY CIRCUIT' or similar must be posted at:
- Every emergency receptacle only
- The emergency panelboard and all boxes containing emergency wiring (Correct answer)
- The transfer switch only
- The main service entrance
Correct answer: The emergency panelboard and all boxes containing emergency wiring
NEC 700.10(A) requires a permanent sign at each box, enclosure, or panelboard containing emergency wiring to identify it as an emergency circuit.
Question 6: When a generator serves both emergency and legally required standby loads, the two systems must:
- Share a single transfer switch to reduce cost
- Have separate transfer switches unless the generator has sufficient capacity (Correct answer)
- Always be served by two separate generators
- Operate on the same circuit from the generator panelboard
Correct answer: Have separate transfer switches unless the generator has sufficient capacity
NEC 700.12 and 701.12 allow one generator to serve both systems if it has adequate capacity and separate transfer switches are provided for each system.
Question 7: Under NFPA 110, a Level 1 emergency power supply system (EPSS) is used when failure of equipment would result in:
- Minor inconvenience
- Significant financial loss
- Loss of human life or serious injuries (Correct answer)
- Interruption of essential communications only
Correct answer: Loss of human life or serious injuries
NFPA 110 Level 1 applies where failure of the EPSS could cause loss of human life or serious injuries to patients or occupants.
CEI Emergency & Standby Systems 3
NEC 700.3 requires emergency systems to be tested under load at what minimum frequency?