TN LLE Overcurrent Protection 3

Question 1

Per NEC 230.90(A), what is the maximum rating of the service overcurrent device relative to the conductor ampacity?

Accepted Answer

Must not exceed the allowable ampacity of the service-entrance conductors

Answer

NEC 230.90(A) requires the service overcurrent device rating to not exceed the allowable ampacity of the service-entrance conductors.

Question 2

What is the purpose of ground-fault protection of equipment (GFPE) per NEC 230.95?

Accepted Answer

To detect ground faults and disconnect the service to prevent equipment damage and fire on solidly grounded wye services of more than 150V to ground and 1000A or more

Answer

NEC 230.95 requires GFPE on solidly grounded wye services exceeding 150V to ground and 1000A or more to detect arcing ground faults that can cause fires.

Question 3

Per NEC 240.83(D), what marking is required on circuit breakers used to switch 120V or 277V fluorescent lighting?

Accepted Answer

SWD (Switching Duty)

Answer

NEC 240.83(D) requires circuit breakers used for switching fluorescent lighting to be marked SWD (Switching Duty).

Question 4

What is the NEC requirement for coordination between overcurrent devices in a series (selective coordination)?

Accepted Answer

Coordination is required for certain critical systems like emergency, legally required standby, and healthcare systems

Answer

NEC sections 700.32, 701.27, and 517.26 require selective coordination for emergency systems, legally required standby systems, and healthcare essential electrical systems.

Question 5

Per NEC 240.86, what is the maximum distance for a series-rated system where the line-side device protects load-side devices?

Accepted Answer

No distance limit as long as the combination is tested and listed

Answer

NEC 240.86 does not impose a specific distance limit. The series combination must be tested and listed by a testing laboratory.

TN LLE - Tennessee Limited Licensed Electrician Practice Test

TN LLE - Tennessee Limited Licensed Electrician Practice Test

TN LLE Overcurrent Protection 3