Journeyman Electrician’s Exam Journeyman Electrician's Emergency and Standby Systems

Question 1

According to NEC Article 700, emergency systems must supply power within how many seconds after loss of normal power?

Accepted Answer

10 seconds

Answer

NEC 700.12 requires emergency systems to restore power within 10 seconds of normal power loss to protect life safety.

Question 2

Which NEC article specifically governs Legally Required Standby Systems?

Accepted Answer

Article 701

Answer

NEC Article 701 covers Legally Required Standby Systems, which are mandated by government agencies for safety but are not immediate life-safety emergency loads.

Question 3

What is the minimum battery operating duration required for unit equipment emergency lighting under NEC 700.12(F)?

Accepted Answer

90 minutes

Answer

NEC 700.12(F) requires unit equipment to maintain adequate illumination for a minimum of 90 minutes from battery backup.

Question 4

Emergency system wiring must remain entirely independent of all other wiring EXCEPT in which location?

Accepted Answer

Transfer equipment enclosures

Answer

NEC 700.10(B)(5) specifically allows emergency and normal wiring to share an enclosure only within transfer equipment, where connection of both systems is inherently necessary.

Question 5

An automatic transfer switch (ATS) for emergency systems must be designed to:

Accepted Answer

Prevent interconnection of normal and emergency sources

Answer

NEC 700.5(A) requires transfer equipment to prevent the inadvertent interconnection of the normal and emergency power sources to avoid backfeed and equipment damage.

Journeyman Electrician’s Exam Practice Test

Journeyman Electrician’s Exam Practice Test

Journeyman Electrician’s Exam Journeyman Electrician's Emergency and Standby Systems