Kidde FX-64 - Worksheet Method

Appendix B: Worksheets
190 P/N 3102352-EN • REV 005 • ISS 28DEC18
Worksheet method
Use this worksheet to determine the maximum cable length of a notification appliance circuit
for a given number of appliances.
Use this worksheet only if all the appliances are regulated. That is, they must have a minimum
operating voltage of 16 V. For other appliances, use the “Equation method.”
NAC cable length
NAC1 NAC2 NAC3 NAC4
Total operating current [1]
A
Load factor (
FX-64 panel) ×
0.20
0.20 0.20 0.20
V/A
Load factor (
FX-1000 panel) 0.24 0.24 0.24 0.24
Load voltage drop
= V
Source voltage
20.4
20.4 20.4 20.4
V
Load voltage drop
− V
Minimum voltage
= V
Regulated appliance voltage
− 16.0 16.0 16.0 16.0 V
Voltage drop [2]
= V
Total operating current
÷ A
Maximum resistance
= Ω
Wire resistance
(Ω/ft) [3] ÷
Maximum wire length
= ft.
÷ 2 2 2 2
Maximum cable length
= ft.
[1]
Total of the maximum operating currents for all appliances as specified for FWR power. See the appliance
installation sheets for operating currents.
[2]
This voltage drop is valid for regulated notification appliances only. For unregulated appliances, see “
Equation
method
” on page 191.
[3]
Use the manufacturer’s published wire resistance expressed in ohms per foot. For typical values, see
Table 48 on page 191.