Fire Alarm Circuit Voltage Drop Calculator

Calculate voltage drop for fire alarm circuits to verify NFPA 72 compliance.

AWG wire size for the fire alarm circuit. NFPA 72 commonly uses 14 or 12 AWG.
One-way distance from the panel to the farthest device on the circuit.
ft
Total number of notification or initiating devices on the circuit.
Current draw per device in alarm/active mode. Typical horn/strobe: 100-300 mA.
mA
Nominal panel supply voltage. Typically 24 VDC for fire alarm systems.
V

Results

Total Current Draw-A
Voltage Drop-V
Voltage Drop Percentage-%
End-of-Line Voltage-V
NFPA 72 Status-
References: NFPA 72 — National Fire Alarm and Signaling Code, NEC Article 760.