IEC Grounding and Bonding 5

Question 1

In a feeder circuit, if the equipment grounding conductor is increased in size above the minimum required by Table 250.122, what must also be increased proportionally?

Accepted Answer

The neutral conductor

Answer

Per NEC 250.122(B), if the ungrounded conductors are increased in size, the equipment grounding conductor must be increased proportionally — and the neutral must also be evaluated for proper sizing.

Question 2

Per NEC 250.64(B), a grounding electrode conductor installed exposed on the exterior of a building must be protected from physical damage by:

Accepted Answer

Iron or steel conduit, PVC conduit, EMT, or other approved means

Answer

NEC 250.64(B) permits the grounding electrode conductor to be protected by iron/steel conduit, PVC conduit, EMT, or other approved means when exposed to physical damage.

Question 3

When multiple electrodes are installed to meet code requirements, what is the minimum spacing between driven ground rods per NEC 250.53(B)?

Accepted Answer

6 feet

Answer

NEC 250.53(B) requires that where multiple rod, pipe, or plate electrodes are installed, they must be spaced at least 6 feet apart.

Question 4

Which of the following conditions allows a single ground rod to serve as the only grounding electrode without a supplemental electrode?

Accepted Answer

When the resistance to ground is 25 ohms or less

Answer

Per NEC 250.56, a single rod electrode does not require supplemental electrodes if the measured resistance to ground is 25 ohms or less.

Question 5

What NEC section governs bonding requirements for swimming pools, hot tubs, and similar installations?

Accepted Answer

Article 680

Answer

Article 680 covers the special requirements for swimming pools, fountains, and similar installations, including the equipotential bonding requirements.

IEC - Independent Electrical Contractors Practice Test

IEC - Independent Electrical Contractors Practice Test

IEC Grounding and Bonding 5