CME Grounding, Bonding & Overcurrent Protection 2

Question 1

Per NEC 240.4(D), what is the maximum overcurrent protection permitted for a 12 AWG copper branch-circuit conductor?

Accepted Answer

20A

Answer

15A

Answer

25A

Answer

30A

Question 2

What is the minimum burial depth for a ground ring below the surface of the earth per NEC 250.52(A)(4)?

Accepted Answer

30 inches

Answer

18 inches

Answer

24 inches

Answer

36 inches

Question 3

When conductors are installed in parallel in multiple raceways, how must equipment grounding conductors be installed per NEC 250.122(F)?

Accepted Answer

In each raceway, each sized per Table 250.122 based on the overcurrent device

Answer

In only one raceway, sized for total combined load

Answer

Only required in raceways containing the largest conductor

Answer

Not required if metallic raceways serve as the EGC

Question 4

A concrete-encased electrode (Ufer ground) must contain at least how many feet of bare copper conductor or steel rebar per NEC 250.52(A)(3)?

Accepted Answer

20 feet

Answer

10 feet

Answer

15 feet

Answer

25 feet

Question 5

What is the primary function of the equipment grounding conductor (EGC) in a branch circuit?

Accepted Answer

To provide a low-impedance fault current path that enables overcurrent device operation

Answer

To carry normal load current back to the neutral bus

Answer

To equalize voltage between ungrounded phase conductors

Answer

To reduce electromagnetic interference in the wiring system

Question 6

Per NEC 230.95, ground-fault protection of equipment (GFPE) is required for solidly grounded wye services exceeding 150V to ground but not exceeding 600V phase-to-phase when the service disconnect is rated at or above:

Accepted Answer

1000A

Answer

100A

Answer

600A

Answer

800A

Question 7

A supply-side bonding jumper is used to bond metal enclosures on which side of the service or separately derived system?

Accepted Answer

The supply side, between the service or separately derived system source and the first disconnecting means

Answer

The load side of all distribution panelboards

Answer

The load side of the main service disconnect only

Answer

Only at grounding electrode connections