GE Security FireShield FS1004 - Notification Appliance Voltage Drop Calculation

Calculations
FireShield Technical Reference Manual A.3
Notification appliance voltage drop calculation
NAC 1 voltage drop calculations
Circuit length Total circuit
current [2]
Wire resistance
per 1000 ft [1]
Voltage
drop
feet x amps x
Ω÷ 1000 =
Panel
voltage
Voltage
drop
End of line
voltage [3]
Voltage
drop
Panel
voltage
Voltage
drop %
[4] – =
÷
[4] =
NAC 2 voltage drop calculations
Circuit length Total circuit
current [2]
Wire resistance
per 1000 ft [1]
Voltage
drop
feet x amps x
Ω÷ 1000 =
Panel
voltage
Voltage
drop
End of line
voltage [3]
Voltage
drop
Panel
voltage
Voltage
drop %
[4] – =
÷
[4] =
NAC 3 voltage drop calculations
Circuit length
Total circuit
current [2]
Wire resistance
per 1000 ft [1]
Voltage
drop
feet x amps x
Ω÷ 1000 =
Panel
voltage
Voltage
drop
End of line
voltage [3]
Voltage
drop
Panel
voltage
Voltage
drop %
[4] – =
÷
[4] =
NAC 4 voltage drop calculations
Circuit length Total circuit
current [2]
Wire resistance
per 1000 ft [1]
Voltage
drop
feet x amps x
Ω÷ 1000 =
Panel
voltage
Voltage
drop
End of line
voltage [3]
Voltage
drop
Panel
voltage
Voltage
drop %
[4] – =
÷
[4] =
Notes
[1] Use 3.5 Ω for 12 AWG and 2.5 sq mm wire, 5.2 Ω for 14 AWG and 1.5 sq mm wire, 8.0 Ω for 16 AWG and 1.0 sq mm wire,
and 13.0 Ω for 18 AWG and 0.75 sq mm wire.
[2] Use the filtered 20 Vdc Average Operating Current ratings found on the installation or catalog sheet of each device.
[3] Cannot drop below 17 Vdc.
[4] 18.6 V for 230 V at 50 Hz, 18.8 V for 230 V 60 at Hz, 18.9 V for 120 V at 60 Hz