Fire Alarm and Life Safety Systems
Fire alarm work is governed by NFPA 72 and Article 760, with California amendments and local fire authority requirements. A candidate must understand initiating devices (smoke, heat, duct, waterflow, tamper), notification appliances, and the circuit classes: Class A survives a single open, Class B does not; Class X adds isolation. Know survivability requirements for risers, the difference between protected premises and supervising station systems, and how addressable systems report device status. Testing and inspection intervals, record of completion, and as-built documentation are frequent exam topics.
Traps: confusing Class A and Class B, assuming notification appliance circuit voltage drop is negligible, and forgetting that smoke detector spacing is not simply "one per room." Also watch the interface between fire alarm and HVAC shutdown, elevator recall, and door release-these are monitored and supervised functions, not optional extras.
Rule of thumb: notification circuits must maintain minimum operating voltage at the last appliance; calculate drop, do not assume.
Worked example: a 24 V notification circuit with 12 appliances. Sum the current, compute the round-trip resistance, and verify the last device sees at least the listed minimum; if not, split the circuit or use a booster supply.