NEC Special Occupancies Questions and Answers

Question 1

An electrician is installing wiring in a Class I, Division 1 hazardous location. Which of the following wiring methods is generally permitted for this environment according to NEC Article 501?

Accepted Answer

Threaded rigid metal conduit (RMC)

Answer

NEC Section 501.10(A) specifies the wiring methods permitted in Class I, Division 1 locations due to the continuous presence of flammable gases or vapors. Threaded rigid metal conduit (RMC) or threaded steel intermediate metal conduit (IMC) are primary methods listed because their construction and threaded connections are designed to contain an internal explosion and prevent it from igniting the surrounding hazardous atmosphere.

Question 2

In a commercial repair garage without adequate ventilation, what is the classification of the area up to 18 inches above the main floor, according to NEC Article 511?

Accepted Answer

Class I, Division 2

Answer

According to NEC Section 511.3(C)(1)(b), in a major repair garage where ventilation is not provided, the area up to 18 inches above the floor is classified as a Class I, Division 2 hazardous location. This classification is due to the potential for flammable gasoline vapors, which are heavier than air, to accumulate near the floor in ignitable concentrations under abnormal conditions.

Question 3

What is the minimum number of receptacles required at each patient bed location in a general care area of a health care facility, as specified in NEC Article 517?

Accepted Answer

Eight

Answer

NEC Section 517.18(B) mandates that each patient bed location in a general care area be provided with a minimum of eight receptacles. This requirement was increased from four to eight in a previous code cycle to accommodate the growing number of electronic medical devices used for patient care. These receptacles must also be listed as "hospital grade."

Question 4

According to NEC Article 525, which of the following is required for all 125-volt, single-phase, 15- and 20-ampere non-locking-type receptacles readily accessible to the general public at a carnival?

Accepted Answer

They must have ground-fault circuit-interrupter (GFCI) protection.

Answer

NEC Section 525.23(A) requires that all 125-volt, single-phase, 15- and 20-ampere non-locking-type receptacles readily accessible to the general public or used for equipment disassembly/reassembly at carnivals, circuses, and fairs must be provided with GFCI protection for personnel.

Question 5

An electrician is installing receptacles near a permanently installed outdoor swimming pool at a private residence. According to NEC Article 680, all 125-volt, 15- and 20-ampere receptacles located within what distance of the inside walls of the pool must be GFCI protected?

Accepted Answer

20 feet

Answer

NEC Section 680.22(A)(4) requires that for other than storable pools, all 125-volt, 15- and 20-ampere receptacles located within 20 feet of the inside walls of the pool must be protected by a ground-fault circuit-interrupter (GFCI).

NEC Practice Test

NEC Practice Test

NEC Special Occupancies Questions and Answers