A communication and low voltage contractor installs, services and maintains all types of communication and low voltage systems which are energy limited and do not exceed 91 volts. These systems include, but are not limited to telephone systems, sound systems, cable television systems, closed-circuit video systems, satellite dish antennas, instrumentation and temperature controls, and low voltage landscape lighting. Low voltage fire alarm systems are specifically not included in this section.
Authority cited: Sections 7008 and 7059, Reference: Sections 7058 and 7059 (Business and Professions Code)
Content of the Examination
The Low Voltage Systems (C-7) Examination is divided into four major sections. These sections are:
1. Pre-Installation, Coordination, & Design (15%)
Interpretation and application of plans for low voltage systems
Compliance with codes
Coordination with owner, architect, & other trades
2. Installation of Low Voltage Systems (48%)
Pre-wiring
Installation of various low voltage systems (e.g., fiber optic, voice, and data, cable TV/satellite)
Testing methods and testing equipment
3. Troubleshooting Low Voltage Systems (13%)
Troubleshooting
Repair/Replacement of low voltage systems and components
4. Safety (24%)
Identification of work site hazards
Safe work practices
*Percentages are approximate*
Sample Questions
The following questions are typical of the types of items that are on the examination. The correct answer is highlighted.
1. What is the proportional relationship between conductor length and conductor size?
resistance
impedance
capacitance
attenuation
2. When running low voltage cables in a ceiling that is being used for air handling, what type of cable should be installed?
fiber-optic cable
shielded cable
PVC-jacketed cable
plenum-rated cable
3. What are the general wiring requirements for a 70 volt background music-only sound system with minimal voltage drop?
one pair of No. 14 AWG wire
one pair of No. 16 AWG wire
one pair of No. 18 AWG wire
one pair of No. 22 AWG wire
*All questions are written and reviewed by licensed contractors who are actively working in the field*