Fire-Lite MS-9050UDC Addressable Fire Alarm Control Panel - Manual (Page 38)

38 MS-9050 Series Manual — P/N 52413:G 4/14/2014
Installation ANN-BUS Devices
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
The total worst case current is calculated as follows:
Using this value and referring to the Wiring Distance Table 2.1 on page 37, it can be found that the
available options are:
 463 feet maximum using 22 Gauge wire
 1,172 feet maximum using 18 Gauge wire
 1,866 feet maximum using 16 Gauge wire
 2,953 feet maximum using 14 Gauge wire
Wire Gauge Ohms per 1,000 feet (Rpu)
22 16.2
18 6.4
16 4.02
14 2.54
Wire Gauge Maximum Wire Length
18 312 feet
16 497 feet
14 787 feet
12 1,250 feet
ANN-80 Current Draw = 3 X 0.040 amps = 0.120 amps
ANN-S/PG Current Draw = 1 X.0.040 amps = 0.040 amps
ANN-I/O Current Draw = 1 X.0.200 amps = 0.200 amps
Total Worst Case Current Draw = 0.360 amps