Wiring Distance Calculation Example - Fire-Lite Alarms MS-9600LS Manual

Product Description
capacitance is the limiting factor. These cases are marked in the chart with an asterisk (*). Maxi-
mum length can never be more than 6,000 feet (1,800 m), regardless of gauge used. The formula
used to generate this chart is shown in the note below.
Total Worst Case Current
The following formulas were used to generate the wire distance chart:
Exception: When using the ANN-RLY module, the installer must ensure that the maximum
24VDC power line drop does not exceed 0.3 volts. This results in the following wiring limitations:

Wiring Distance Calculation Example:

Suppose a system is configured with the following ANN-BUS modules:
• 3 ANN-80 Remote Fire Annunciators
• 1 ANN-S/PG Serial/Parallel Printer Interface Module
• 1 ANN-I/O LED Driver Module
24
Wiring Distance: ANN-BUS Modules to FACP
22 Gauge
Draw (amps)
0.100 1,852 ft.
0.200
0.300
0.400
0.500
Table 1.1 Wiring Distances
Maximum Resistance (Ohms)
Maximum Wire Length (feet)
(6,000 feet maximum)
where: Rpu = Ohms per 1,000 feet for various Wire Gauges (see table below)
Wire Gauge
22
18
16
14
Wire Gauge
18
16
14
12
18 Gauge
4,688 ft.
926 ft. 2,344 ft.
617 ft. 1,563 ft.
463 ft. 1,172 ft.
370 ft. 938 ft.
6.0 volts
=
Total Worst Case Current Draw (amps)
Maximum Resistance (Ohms)
=
Rpu
Ohms per 1,000 feet (Rpu)
Maximum Wire Length
312 feet
497 feet
787 feet
1,250 feet
MS-9600LS Series Manual — P/N 52646:B2 2/12/2010
Accessories
16 Gauge 14 Gauge
* 6,000 ft. *6,000 ft.
3,731 ft. 5,906 ft.
2,488 ft. 3,937 ft.
1,866 ft. 2,953 ft.
1,493 ft. 2,362 ft.
*500
16.2
6.4
4.02
2.54