Honeywell Farenhyt IFP-2000 Manual page 47

Model IFP-2000/ECS Installation Manual
Note: The following formulas were used to generate the wire distance chart:
Maximum Resistance (Ohms) =
Maximum Wire Length (Feet) =
(6000 feet maximum)
where: Rpu = Ohms per 1000 feet for various wire gauges (see table below)
Table 4-2: Typical Wire Resistance Per 1000 ft. Using Copper Wire
Wiring Distance calculation example:
Suppose a system is configured with the following SBUS modules:
2 - Module RA-2000 Fire Annunciator
1 - RPS-1000 Intelligent Power Expander
1 - 5865 LED Annunciator
1 - 5824 Serial/Parallel Interface Module
The total worst case current is calculated as follows:
RA-2000 Current Draw
RPS-1000 Current Draw
5865 Current Draw
5824 Current Draw
Total Worst Case Current Draw
Using this value, and referring to the Wiring Distance table, it can be found that the available options are:
370 feet maximum using 22 Gauge wire
938 feet maximum using 18 Gauge wire
1493 feet maximum using 16 Gauge wire
2362 feet maximum using 14 Gauge wire
Total Worst Case Current Draw (amps)
Maximum Resistance (Ohms)
Wire Gauge Ohms per 1000 feet (Rpu)
22
18
16
14
= 2 x .120 amps
= 1 x .010 amps
= 1 x .200 amps
= 1 x .040 amps
4-7
6.0 Volts
* 500
Rpu
16.2
6.4
4.02
2.54
= .240 amps
= .010 amps
= .200 amps
= .040 amps
= .490 amps
151430-L8