C7 Electrical Codes & Safety Regulations 2 — Questions and Answers
Question 1: Under California's Title 24, which document governs energy efficiency requirements for low voltage lighting control systems in commercial buildings?
- California Electrical Code Article 411
- California Energy Code (Part 6) (Correct answer)
- NFPA 72 Chapter 10
- NEC Article 720
Correct answer: California Energy Code (Part 6)
Title 24, Part 6 (California Energy Code) sets energy efficiency standards for lighting controls, including low voltage dimming and occupancy sensor systems in commercial buildings.
Question 2: A C7 contractor installs a Class 2 wiring system. According to the NEC, what is the maximum allowable voltage for a Class 2 circuit?
- 30 volts
- 60 volts (Correct answer)
- 150 volts
- 50 volts
Correct answer: 60 volts
NEC Article 725 defines Class 2 circuits as those operating at 60 volts or less under normal conditions.
Question 3: Which Cal/OSHA standard specifically addresses electrical safety requirements for low voltage construction work?
- Title 8, Section 2940 (Correct answer)
- Title 8, Section 1512
- Title 8, Section 3203
- Title 8, Section 4850
Correct answer: Title 8, Section 2940
Cal/OSHA Title 8, Section 2940 covers electrical safety orders applicable to construction, including low voltage installation work.
Question 4: When installing a fire alarm system in California, the C7 contractor must comply with which primary code for system design and installation?
- NEC Article 800
- NFPA 72 (National Fire Alarm and Signaling Code) (Correct answer)
- IBC Chapter 9
- UL 2572
Correct answer: NFPA 72 (National Fire Alarm and Signaling Code)
NFPA 72 is the National Fire Alarm and Signaling Code adopted by California and governs the design and installation of fire alarm systems.
Question 5: In California, who has authority to adopt local amendments to the California Electrical Code (CEC)?
- Individual licensed contractors
- Local jurisdictions (cities and counties) (Correct answer)
- The California Contractors State License Board (CSLB)
- The California Public Utilities Commission
Correct answer: Local jurisdictions (cities and counties)
Local jurisdictions such as cities and counties may adopt amendments to the CEC that are more restrictive than state minimums, provided they follow the amendment process.
Question 6: A low voltage cable is run through a plenum space. Which type of cable jacket is required by the NEC?
- CM-rated (Communications) cable
- CMP-rated (Communications Plenum) cable (Correct answer)
- CMR-rated (Communications Riser) cable
- CMX-rated cable
Correct answer: CMP-rated (Communications Plenum) cable
NEC Article 800 requires CMP (plenum-rated) cable in air-handling plenum spaces due to its low smoke and flame-spread characteristics.
Question 7: Under NFPA 70E, what is the minimum approach boundary designation for workers performing low voltage energized electrical work below 50 volts?
- Arc flash boundary applies the same as higher voltages
- No shock protection boundary is required below 50 volts (Correct answer)
- Limited approach boundary of 12 inches is always required
- Restricted approach boundary of 1 inch applies
Correct answer: No shock protection boundary is required below 50 volts
NFPA 70E does not require shock protection boundaries for systems operating below 50 volts unless the work creates a risk of arc flash.
C7 Electrical Codes & Safety Regulations 2
Under California's Title 24, which document governs energy efficiency requirements for low voltage lighting control systems in commercial buildings?