Electrical Theory for Fire Alarm
The electricity behind a fire alarm system, followed through Bramwell Fire Protection's Charlotte crew: Ohm's law, series and parallel circuits, meters, wire resistance, power supplies, sealed lead-acid batteries and battery calculations to NFPA 72, voltage drop on notification circuits, supervision and ground faults, and NEC Article 760 wiring methods, ending with the power design for a high-rise.
FAT-130 12 lessons · 3 h 49 min ▶ Video lessons coming soon
Offered by HSM University · Fire Alarm Systems
This is the American version of this course. See the Canadian version.
What you'll learn
- Describe how electricity enters, flows through and is stored in a fire alarm system, and why its circuits are designed for the worst case
- Apply Ohm's law and the power equation to fire alarm circuits, and explain why strobe current rises as supply voltage falls
- Analyze series and parallel circuits, including notification circuits fed by wire segments in series and batteries in series pairs
- Use multimeters, clamp meters and insulation testers safely to measure voltage, resistance, current and insulation on fire alarm systems
- Calculate conductor resistance from wire gauge, length and temperature, and choose conductor sizes for fire alarm circuits
- Explain the requirements for the fire alarm system's primary power under NFPA 72 and NEC Article 760, and load power supplies within their ratings
- Explain how sealed lead-acid batteries are charged, how they age and how they are installed and tested
- Calculate battery capacity using the NFPA 72 durations, the device list and a safety margin, and check the result against the charger and cabinet
- Calculate voltage drop on notification appliance circuits by the lumped-load and point-to-point methods under worst-case conditions
- Explain how panels supervise initiating, notification and signaling line circuits, and locate opens, shorts and ground faults
- Select cable types and wiring methods for fire alarm circuits under NEC Article 760, and apply NFPA 72 pathway survivability levels
- Prepare and check the loading, battery and voltage-drop calculations for a high-rise remote power supply
Course content
12 lessons · 3 h 49 min total · final exam
- 1 Electricity in fire alarm systems 19 min · quiz
- 2 Voltage, current, resistance and Ohm's law 20 min · quiz
- 3 Series and parallel circuits 20 min · quiz
- 4 Meters and measurement for fire alarm work 19 min · quiz
- 5 Wire, resistance and conductor sizing 18 min · quiz
- 6 Power supplies and the primary power source 20 min · quiz
- 7 Secondary power: batteries and standby 19 min · quiz
- 8 Battery calculations 18 min · quiz
- 9 Voltage drop on notification appliance circuits 19 min · quiz
- 10 Supervision: end-of-line devices and ground faults 20 min · quiz
- 11 Wiring methods and cable types (NEC Article 760) 19 min · quiz
- 12 Capstone: power and voltage-drop calculations for a high-rise 18 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
The electricity behind a fire alarm system, followed through Bramwell Fire Protection's Charlotte crew: Ohm's law, series and parallel circuits, meters, wire resistance, power supplies, sealed lead-acid batteries and battery calculations to NFPA 72, voltage drop on notification circuits, supervision and ground faults, and NEC Article 760 wiring methods, ending with the power design for a high-rise.