Journeyman Electrician's Emergency and Standby Systems Flashcards
7 cards from real Journeyman Electrician’s Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Journeyman Electrician's Emergency and Standby Systems flashcards as text
Whether a generator neutral must be bonded to its frame as a separately derived system depends primarily on:
Answer: Whether the ATS switches the neutral conductor
A 3-pole ATS retains the normal service neutral (not separately derived), while a 4-pole ATS switches the neutral, making the generator a separately derived system requiring neutral bonding per NEC 250.30.
Emergency system feeder conductors must have an ampacity sufficient to:
Answer: Handle all emergency loads that could be energized simultaneously
NEC 700.10(A) requires emergency feeders to have adequate ampacity for all emergency loads that could be connected at the same time — no demand factor reduction is permitted.
A central battery unit used as an emergency lighting source must supply the connected load for a minimum of:
Answer: 90 minutes
NEC 700.12(F)(1) requires central battery systems for emergency lighting to supply adequate power for not less than 90 minutes.
Exit signs required for means of egress fall under which NEC article?
Answer: Article 700 — Emergency Systems
Exit signs are life-safety loads classified under Emergency Systems (Article 700) because their failure could prevent safe egress during a power outage.
Emergency power systems installed in a health care facility must also comply with which NEC article in addition to Article 700?
Answer: Article 517
NEC Article 517 contains additional health care facility requirements for essential electrical systems that supplement the general requirements in Article 700.
A storage battery used as an emergency source per NEC 700.12(A) must maintain voltage at or above what percentage of normal rated voltage under full load?
Answer: 87.5%
NEC 700.12(A) requires storage battery emergency systems to maintain not less than 87.5% of normal rated voltage under full load conditions.
When emergency system wiring must occupy the same enclosure as normal wiring at a transfer switch, this is permitted because:
Answer: NEC 700.10(B)(5) specifically exempts transfer equipment from the independence requirement
NEC 700.10(B)(5) provides a specific exception to the wiring independence rule at transfer equipment, since this is the inherent connection point between the two sources.