When sizing wire for a long notification circuit, which factor is the most critical to ensure all appliances operate correctly during an alarm?

Question: When sizing wire for a long notification circuit, which factor is the most critical to ensure all appliances operate correctly during an alarm?

Answer options: ✅ Operating voltage of the devices at the end of the line

• The color of the wire jacket
• The number of ground faults on the circuit
• The temperature of the ambient air outdoors

Correct answer: Operating voltage of the devices at the end of the line

Explanation: Voltage Drop = 2 x L x R x I / 1000. Voltage drop must not exceed the manufacturer's specified minimum operating voltage (typically 15% of 24V, i.e., 20.4V), but wire size calculations must factor in end-of-line voltage. If the last device sees less than rated voltage, it may not sound.