Low Voltage Systems (C-7) · Lesson 4 of 4

Fire Alarm Layout Numbers Printed in CFC Section 907

"Fire Alarm Layout Numbers Printed in CFC Section 907" is lesson 4 of 4 in the Low Voltage Systems (C-7) Learning Hub. It opens with "Where the California Fire Code Stops and NFPA 72 Starts" and works through 5 short steps, then a worked example you can check yourself against.

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Steps in this lesson

  1. Where the California Fire Code Stops and NFPA 72 Starts
  2. Manual Fire Alarm Boxes
  3. Zones
  4. Audible Appliance Sound Levels
  5. Visible Appliances and Spare Capacity

The worked example in the course applies this lesson to a realistic job in 4 steps, from "Manual boxes" through "Visible alarms".

What you'll be able to do

  • Explain the main idea of "Fire Alarm Layout Numbers Printed in CFC Section 907" in plain language you can use on the exam.
  • Apply this step with confidence: "Zones".
  • Apply this step with confidence: "Audible Appliance Sound Levels".
  • Apply this step with confidence: "Visible Appliances and Spare Capacity".
  • Test yourself on the worked example and the quick-check quiz inside the classroom.
Fire Alarm Numbers From CFC Section 907 one floor plate gold = exits, red = manual boxes (within 5 ft) 250 ft (limit 300 ft) 80 ft Area = 250 x 80 = 20,000 sq ft under 22,500 sq ft: 1 zone per floor Numbers for this hotel Zones: 4 floors = 4 zones Boxes: 3 exits x 4 floors = 12 Box handle height: 42 in. to 48 in. Ambient 52 dBA: 52 + 15 = 67 Max sound 70 dBA: 70 + 5 = 75 Use the greater: 75 dBA 120 units: 101 to 150 row = 12 units with visible alarms 4 zones, 12 manual boxes, 75 dBA audible, 12 visible-alarm units Wiring, power supply and testing are handed to NFPA 72 by CFC §907.6 and §907.7 Source: 2025 CFC §907.4.2, §907.5.2.1.1, Table 907.5.2.3.2, §907.6.4 CC
The diagram for this lesson, exactly as it appears in the Learning Hub.

The first steps of this lesson

Step 1: Where the California Fire Code Stops and NFPA 72 Starts

2025 CFC §907 prints some design numbers itself and sends the rest to NFPA 72. Wiring, power supplies, monitoring, acceptance testing and maintenance are handed to NFPA 72 in §907.6.1, §907.6.2, §907.6.6, §907.7 and §907.8, and NFPA 72 is not a California code book on disk. So battery sizing and detector spacing are not taught here. This lesson uses the numbers CFC §907 prints. §907.6.1 also says wiring must comply with the California Electrical Code.

Step 2: Manual Fire Alarm Boxes

CFC §907.4.2.1: manual fire alarm boxes are located not more than 5 feet (1524 mm) from the entrance to each exit. In buildings not protected by an automatic sprinkler system (903.3.1.1 or 903.3.1.2), additional boxes are located so that travel to the nearest box does not exceed 200 feet (60 960 mm). §907.4.2.2: mounted not less than 42 inches (1067 mm) and not more than 48 inches (1372 mm) from the floor to the highest point of the activating handle. §907.4.2.3: red. §907.4.2.7: operable with one hand.

The remaining 3 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.

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