36 MS-5UD & MS-10UD Series Manual — P/N 52626:C7 6/12/2018
Installation ANN-BUS Devices
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:
• 2 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 2.2 on page 35, 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
Maximum Resistance (Ohms) = 6.0 Volts
Total Worst Case Current Draw (amps)
Maximum Wire Length (feet)
(6,000 feet maximum)
= Maximum Resistance (Ohms) *500
Rpu
where: Rpu = Ohms per 1,000 feet for various Wire Gauges (see table below)
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 = 2 X 0.040 amps = 0.080 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 = 0.320 amps