E2 Special Occupancies 2

Question 1

In a Class I, Division 1 location, which wiring method is specifically permitted by the NEC?

Accepted Answer

Threaded rigid metal conduit (RMC) with listed fittings

Answer

Type NM cable in conduit

Answer

Type MC cable with standard connectors

Answer

PVC conduit with expansion fittings

Question 2

Which of the following best describes a Class II, Division 1 location under NEC Article 502?

Accepted Answer

An area where combustible dust is in suspension in the air under normal operating conditions

Answer

An area where flammable gases exist continuously under normal conditions

Answer

An area where ignitable fibers are stored in open containers

Answer

An area adjacent to a Class I location where vapors may occasionally drift

Question 3

Under NEC Article 504, an intrinsically safe system is one in which any spark or thermal effect is incapable of causing ignition under which condition?

Accepted Answer

Both normal and abnormal conditions as specified

Answer

Normal operation only

Answer

Abnormal conditions only

Answer

Startup and shutdown sequences only

Question 4

In a Class I, Zone 0 location per NEC Article 505, flammable concentrations of gases are present:

Accepted Answer

Continuously or for long periods under normal conditions

Answer

Intermittently under abnormal conditions

Answer

Only during equipment failure

Answer

Periodically during maintenance operations

Question 5

When sealing fittings are required in a Class I conduit system at a boundary, where must the seal be installed?

Accepted Answer

Within 18 inches of the enclosure

Answer

Within 36 inches of the enclosure

Answer

At the panel or switchboard only

Answer

At the midpoint of the conduit run

Question 6

Equipment installed in a Class I hazardous location must be marked to show which information as required by NEC 500.8?

Accepted Answer

Class, Division or Zone, Group, and temperature class (T-code)

Answer

Voltage rating and ampacity only

Answer

Manufacturer name and UL listing number only

Answer

Conduit fill percentage and conductor insulation type

Question 7

Class III locations under NEC Article 503 involve which type of hazard?

Accepted Answer

Ignitable fibers or flyings not likely to be in suspension

Answer

Flammable liquids stored above their flash point

Answer

Combustible metal dusts such as magnesium

Answer

Vapors from paint mixing operations