TN LLE Grounding and Bonding 3

Question 1

Per NEC 250.30, what grounding requirements apply to a separately derived system such as a transformer?

Accepted Answer

A system bonding jumper and grounding electrode conductor must be installed at the source

Answer

No grounding is required if the primary is grounded

Answer

Only an equipment ground is needed

Answer

The system can share the service grounding electrode only

Question 2

What is the difference between 'grounding' and 'bonding' as defined by the NEC?

Accepted Answer

Grounding connects to the earth; bonding connects conductive parts together to ensure electrical continuity

Answer

They mean the same thing

Answer

Bonding is for lightning protection; grounding is for fault protection

Answer

Grounding is for AC systems; bonding is for DC systems

Question 3

Per NEC 250.118, which of the following is recognized as an equipment grounding conductor?

Accepted Answer

A copper conductor, EMT, IMC, RMC, or listed flexible metal conduit under specific conditions

Answer

PVC conduit

Answer

NM cable outer sheath

Answer

Duct tape wrapped around a conductor

Question 4

Per NEC 250.68(A), what is required for grounding electrode conductor connections?

Accepted Answer

They must be accessible, except for connections made by listed irreversible compression-type connectors, exothermic welding, or buried connections

Answer

They must be soldered

Answer

All connections must be visible at all times

Answer

No specific accessibility requirement exists

Question 5

What is the minimum size copper bonding jumper required for a 200A service per NEC Table 250.66?

Accepted Answer

4 AWG

Answer

8 AWG

Answer

6 AWG

Answer

2 AWG

Question 6

Per NEC 250.24(A)(5), what is the rule regarding neutral-to-ground connections in subpanels?

Accepted Answer

The grounded conductor (neutral) must not be connected to the equipment grounding conductor or enclosure at subpanels

Answer

They must be bonded together as in the main panel

Answer

An additional bonding jumper is required

Answer

It depends on the panel manufacturer