Calculations
A.4
FireShield Technical Reference Manual
Notification appliance circuit maximum
wire length calculation
Use this worksheet to determine the maximum wire length of
a notification appliance circuit. Fill in one worksheet for each
NAC connected to the panel.
Wire length matrix
Wire lengths in the following table are based on a voltage drop
of 1.9 volts or 10% and total load at the end of the line.
Maximum wire length
Current
required
18 AWG
16 AWG
14 AWG
12 AWG
0.25
584
950
1460
2170
0.50
292
474
730
1084
0.75
194
316
486
722
1.00
146
236
364
542
1.25
116
190
292
434
1.50
92
158
242
362
Maximum signal loss allowed [1]
V
×
1000
Wire resistance per 1000 ft/pair [2]
÷
Ω
Total operating current required [3]
÷
A
Maximum circuit length
ft
Notes
[1] 1.6 V for 230 V at 50 Hz
1.8 V for 230 V at 60 Hz
1.9 V for 120 V at 60 Hz
[2] 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.
[3] Use the filtered 20 Vdc Average Operating Current ratings
found on the installation or catalog sheet of each device.
Summary of Contents for FireShield FS1004
Page 1: ...FireShield Technical Reference Manual P N 3100353 Rev 3 0 12MAY03 ...
Page 10: ...System overview and operation 1 8 FireShield Technical Reference Manual ...
Page 40: ...Programming 3 18 FireShield Technical Reference Manual ...
Page 42: ...Maintenance 4 2 FireShield Technical Reference Manual ...
Page 60: ...Panel specifications D 2 FireShield Technical Reference Manual ...
Page 66: ...Index Z 4 FireShield Technical Reference Manual ...
Page 68: ......