IEC Special Occupancies and Equipment 3

Question 1

What is the minimum burial depth for rigid metal conduit (RMC) under a parking lot?

Accepted Answer

12 inches

Answer

NEC Table 300.5 requires RMC to be buried at least 6 inches under a parking lot when not subject to vehicular traffic, but 24 inches in other cases—however under parking lots with vehicle traffic the minimum is 24 inches.

Question 2

In an agricultural building, equipment that is subject to water and corrosive vapors must be listed for use in:

Accepted Answer

Damp or wet locations

Answer

NEC 547.5 requires electrical equipment in agricultural buildings exposed to water or corrosive vapors to be listed for damp or wet locations.

Question 3

What is the required clearance between a swimming pool and an overhead service drop conductor carrying up to 750 volts?

Accepted Answer

22.5 feet

Answer

NEC 680.8 requires a minimum horizontal clearance of 22.5 feet between a pool and overhead service conductors operating up to 750 volts.

Question 4

In a Class II hazardous location, the primary hazard is from:

Accepted Answer

Combustible dust

Answer

Class II hazardous locations are defined by the presence of combustible dust that can ignite and create an explosive atmosphere.

Question 5

For a temporary power installation at a construction site, GFCI protection is required for all:

Accepted Answer

125-volt, 15- and 20-ampere receptacles

Answer

NEC 590.6 requires GFCI protection for all 125-volt, 15- and 20-ampere receptacles on construction sites.

IEC - Independent Electrical Contractors Practice Test

IEC - Independent Electrical Contractors Practice Test

IEC Special Occupancies and Equipment 3