3M 2475 - Manual (Page 10)

Wiring the System Performance Series
6
Wiring the System
Depending on distance, use twisted pair, 14-22 AWG audio cables when wiring the Wired Intercom System,
components. Figure 7 shows an overview of the cable types and number of conductors required for each unit.
Table 1 shows wire gauge required for different distances between components. We recommend installing a
separate power supply transformer (3M part number 78-8095-0910-8), for each Station Selector located over 100
feet from the Communications Controller,
Note:
The RS 485 cable carries DC power for the Station Selectors, requiring a larger gauge wire.
Figure 7. Cable and Connection Requirements
All Audio Wiring
Wire Gauge
Distance Between
Components
22 Up to-309 feet
20 310-493 feet
18 494-783 feet
16 784-1245 feet
14 1246-1980 feet
RS 485 Cable (only)
Wire Gauge
Distance Between
Components
22 Up to 62 feet
20 63-99 feet
18 100-157 feet
16 158-249 feet
14 250-396 feet
Table 1. Wire Size Requirements