C7 Electrical Codes & Safety Regulations 3 — Questions and Answers
Question 1: A C7 contractor discovers existing low voltage wiring in a wall that is not labeled or identified. What is the first required action before proceeding with work near it?
- Immediately remove the wire
- De-energize and test the circuit to verify it is safe (Correct answer)
- Cover it with conduit and continue work
- Report it to the CSLB only
Correct answer: De-energize and test the circuit to verify it is safe
Before working near unidentified wiring, Cal/OSHA and NFPA 70E require de-energizing and testing to confirm the circuit is safe (lockout/tagout procedure).
Question 2: According to the NEC, low voltage wiring installed in raceways must be separated from power conductors by how much unless it uses a barrier?
- No separation required for low voltage
- Must occupy separate raceways entirely (Correct answer)
- At least 2 inches of separation
- At least 6 inches of separation
Correct answer: Must occupy separate raceways entirely
NEC Article 725 generally requires Class 2 and Class 3 wiring to be separated from power wiring in separate raceways unless using approved barriers or cables with sufficient insulation ratings.
Question 3: Which California agency is responsible for enforcing electrical code compliance on general construction job sites?
- California Contractors State License Board (CSLB)
- California Department of Consumer Affairs
- California Division of Occupational Safety and Health (Cal/OSHA) (Correct answer)
- California State Fire Marshal
Correct answer: California Division of Occupational Safety and Health (Cal/OSHA)
Cal/OSHA enforces electrical safety standards on California construction job sites, including compliance with Title 8 electrical safety orders.
Question 4: Under the CEC, what does the term 'listed' mean when applied to low voltage equipment?
- Approved by the local building department
- Evaluated and found to meet safety standards by a nationally recognized testing laboratory (NRTL) (Correct answer)
- Manufactured in the United States
- Registered with the CSLB
Correct answer: Evaluated and found to meet safety standards by a nationally recognized testing laboratory (NRTL)
Listed equipment has been evaluated by a Nationally Recognized Testing Laboratory (NRTL) such as UL or ETL and found to meet applicable safety standards.
Question 5: A C7 contractor wants to install security camera wiring (CCTV) in a building. Which NEC article primarily governs this installation?
- Article 640 (Audio/Video)
- Article 820 (Community Antenna Television) (Correct answer)
- Article 800 (Communications Circuits)
- Article 830 (Network-Powered Broadband)
Correct answer: Article 820 (Community Antenna Television)
NEC Article 820 covers coaxial cables used for community antenna television (CATV) and CCTV distribution systems.
Question 6: What does the California Building Code require regarding seismic bracing for low voltage system components mounted above suspended ceilings?
- No seismic bracing is required for low voltage components
- Components over 20 lbs must be independently seismically braced (Correct answer)
- All components must be zip-tied to ceiling grid
- Only components over 100 lbs need seismic restraint
Correct answer: Components over 20 lbs must be independently seismically braced
California's adoption of ASCE 7 seismic requirements mandates that mechanical and electrical components (including low voltage equipment) weighing over 20 lbs above suspended ceilings must have independent seismic bracing.
Question 7: Under California law, a C7 contractor who subcontracts work must ensure the subcontractor holds which minimum license?
- No license is required for subcontractors under a C7
- A C-10 (Electrical) license for any electrical work
- An appropriate specialty or general contractor license for the work performed (Correct answer)
- A C7 license identical to the prime contractor
Correct answer: An appropriate specialty or general contractor license for the work performed
California Business and Professions Code requires that subcontractors performing licensed work hold an appropriate contractor's license for the trade or specialty they perform.
C7 Electrical Codes & Safety Regulations 3
A C7 contractor discovers existing low voltage wiring in a wall that is not labeled or identified.
What is the first required action before proceeding with work near it?