C7 Cheat Sheet 2026

The 30 highest-yield C7 facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Under the CEC, a C7 contractor must obtain a building permit for which of the following low voltage installations? → Installing a new fire alarm system in a commercial building
2. Which maintenance activity is typically done on a quarterly basis? → System performance and physical inspection
3. Which type of BAS sensor output signal requires loop-powered transmitter wiring and is immune to voltage drop over long cable runs? → 4–20 mA current loop output
4. On a CCTV system layout drawing, a triangle symbol with a dot inside typically represents: → A security camera
5. What is the maximum distance for a 10GBASE-SR transmission over OM4 multimode fiber? → 400 meters
6. In California, what typically triggers the requirement for a permit for low voltage wiring in a residential remodel? → When new low voltage wiring is run through walls, floors, or ceilings
7. A security camera system shows intermittent video loss only during afternoon hours. What is the MOST likely cause? → Thermal expansion causing loose coaxial connections
8. A card reader at an exterior door grants access intermittently in cold weather. After ruling out software issues, the MOST likely hardware cause is: → The door contact is misaligned due to frame thermal contraction
9. Which cable standard governs the installation of optical fiber in commercial buildings in the United States? → ANSI/TIA-568.3-D
10. When installing a two-wire intercom system in a residential building, what is the primary function of the door strike output on the master intercom station? → To release an electric door strike or magnetic lock to grant entry
11. What does the California Building Code require regarding seismic bracing for low voltage system components mounted above suspended ceilings? → Components over 20 lbs must be independently seismically braced
12. Under California Title 19 regulations, a fire alarm-integrated access control door must unlock upon: → Any fire alarm signal activation
13. What is the minimum bend radius for a Cat 6 UTP cable after installation (static bend)? → 4 times the cable diameter
14. If a single ground rod electrode measures greater than what resistance value must a second grounding electrode be installed per NEC 250.56? → 25 ohms
15. A C7 licensee's license number must be displayed on which business materials under California law? → All contracts, bids, and advertising
16. In a fiber optic system, what does an OTDR 'ghost' event indicate? → A false reflection caused by a strong Fresnel reflection echoing a second time
17. When installing fire alarm wiring in a building with a concrete ceiling, what method is required to support conduit runs per NEC Article 300? → Conduit must be supported at intervals not exceeding 10 feet and within 3 feet of each box
18. A CCTV system's NVR hard drive fails. Before replacing the drive and restoring from backup, the technician should: → Document the drive's serial number and SMART status errors for the maintenance log
19. Under NFPA 72, what is the maximum allowable spacing between smoke detectors on a smooth ceiling with a ceiling height of 10 feet? → 50 feet
20. An AV technician is troubleshooting a ground loop hum in a balanced XLR audio system. The most effective first corrective step is to: → Insert a 1:1 isolation transformer on the affected run
21. When integrating a legacy Modbus RTU device into a BACnet BAS, the most common solution is to use a: → Protocol gateway or converter that maps Modbus registers to BACnet objects
22. Which drawing would show the routing of a backbone fiber cable between two telecom rooms on different floors? → Riser diagram
23. During fire alarm commissioning, smoke detectors are tested using functional test methods. Per NFPA 72, which is acceptable for functional testing? → Using canned aerosol smoke specifically listed for detector testing
24. Which conductor color is used for equipment grounding conductors in low voltage DC systems per NEC guidelines? → Green or bare
25. What is the minimum impedance typically required for speakers in a distributed audio system installed under a C7 license in California? → 8 ohms
26. Which standard governs structured cabling in commercial buildings? → ANSI/TIA-568
27. A 'single-line diagram' for a low-voltage system differs from a wiring diagram because it: → Shows only one wire regardless of actual conductor count
28. In a Class 2 low voltage control wiring installation, equipment grounding conductors are required when: → Any metallic enclosure or raceway is part of the installation
29. A glass break detector using acoustic technology is best positioned: → On the ceiling or wall within the acoustic detection range facing the protected glazing
30. A facial recognition access control system produces a high rate of false rejections for employees wearing masks. The BEST solution is: → Add a secondary credential method such as a card or PIN for masked individuals