C7 Fire Alarm System Installation 2

Question 1

Under NFPA 72, what is the maximum allowable spacing between smoke detectors on a smooth ceiling with a ceiling height of 10 feet?

Accepted Answer

50 feet

Answer

NFPA 72 permits a maximum 30-foot spacing (i.e., 900 sq ft coverage) between smoke detectors on smooth ceilings, but the listed spacing is up to 30 feet center-to-center — however the standard default area is 900 sq ft with a max 30-ft distance, so 30 feet is the correct maximum spacing.

Question 2

Which wire gauge is most commonly required for Class B initiating device circuits in a fire alarm system?

Accepted Answer

22 AWG

Answer

18 AWG or 22 AWG conductors are typically used for initiating device circuits; 22 AWG is the most common minimum for low-current Class B IDC wiring per manufacturer specifications and NFPA 72.

Question 3

A California C7 contractor installs a fire alarm panel in a mechanical room. What is the minimum clearance required in front of the panel for service access per the NEC?

Accepted Answer

30 inches

Answer

NEC 110.26 requires a minimum 30 inches of width and 36 inches of depth working clearance in front of electrical equipment, but the minimum clear width in front of the panel itself is 30 inches.

Question 4

When connecting a two-wire smoke detector to a Class B initiating device circuit, what component is typically placed at the end of the circuit?

Accepted Answer

End-of-line resistor

Answer

An end-of-line (EOL) resistor is placed at the last device on a Class B circuit so the control panel can supervise the circuit for open conditions.

Question 5

Which NFPA standard specifically governs the installation of fire alarm systems in the United States?

Accepted Answer

NFPA 72

Answer

NFPA 72, the National Fire Alarm and Signaling Code, is the primary standard governing the installation, testing, and maintenance of fire alarm systems.

(C7) California C7 Low Voltage Systems Contractor Certification Practice Test

(C7) California C7 Low Voltage Systems Contractor Certification Practice Test

C7 Fire Alarm System Installation 2