Licensed Electrical Contractor Electrical Contractor Electrical Codes & Standards 2 — Questions and Answers
Question 1: Under the NEC, what is the maximum voltage allowed for a Class 2 circuit?
- 150 volts (Correct answer)
- 100 volts
- 30 volts
- 60 volts
Correct answer: 150 volts
NEC Article 725 permits Class 2 circuits to operate at a maximum of 150 volts.
Question 2: According to NFPA 70, what is the minimum working space depth required in front of electrical equipment rated 600 volts or less with exposed live parts on one side?
- 3 feet (Correct answer)
- 4 feet
- 2.5 feet
- 6 feet
Correct answer: 3 feet
NEC Section 110.26(A)(1) Condition 1 requires a minimum of 3 feet of clear working space.
Question 3: What NEC article specifically covers the installation requirements for swimming pool electrical equipment?
- Article 680 (Correct answer)
- Article 690
- Article 625
- Article 700
Correct answer: Article 680
NEC Article 680 covers electrical installations for swimming pools, fountains, and similar installations.
Question 4: Per the NEC, what color must the grounded conductor (neutral) insulation be for sizes 6 AWG or smaller?
- White or gray (Correct answer)
- Green
- Blue
- Orange
Correct answer: White or gray
NEC Section 200.6 requires grounded conductors 6 AWG or smaller to have white or gray insulation.
Question 5: Which NFPA standard is commonly known as the National Electrical Safety Code (NESC) and covers utility installations?
- NFPA 70 does not cover utilities; the NESC is IEEE C2 (Correct answer)
- NFPA 70E
- NFPA 79
- NFPA 75
Correct answer: NFPA 70 does not cover utilities; the NESC is IEEE C2
The NESC is published as IEEE C2 and is separate from NFPA 70, which is the NEC for premises wiring.
Question 6: According to the NEC, what is the minimum burial depth for rigid metal conduit (RMC) installed under a residential driveway?
- 6 inches (Correct answer)
- 12 inches
- 18 inches
- 24 inches
Correct answer: 6 inches
NEC Table 300.5 requires a minimum cover of 6 inches for RMC under areas subject to vehicular traffic.
Licensed Electrical Contractor Electrical Contractor Electrical Codes & Standards 2
Under the NEC, what is the maximum voltage allowed for a Class 2 circuit?