Connecting Signal Lines
See Figure 1. To connect the signal lines of the SelecTone system to the 300VSC, connect a color-
coded twisted pair of audio cables having conductors no smaller than 18 AWG to the TB1-4 and TB1-5
terminals on TB1. Every remote SelecTone signaling device in the system can be connected in parallel
or series to these lines.
For non-SelecTone 25 Vrms speakers, such as ceiling speakers, connect the signal lines directly to
TB1-4 and TB1-5 of terminal block TB1. Signal line losses must be considered when calculating how
many speakers can be connected to the 300VSC.
1
2 3 4 5 6
7 8
SHIELDED TWISTED
PAIR SIGNAL LINES
Connecting to Remote Devices
Install the remote SelecTone device(s) following the instructions included with the device.
Balanced Line Application
For 300GC, 300GCX, 300X, 302GC, 302GCX, 302X, or 50GC speakers, an AM25CK Connector Kit is
required for connection to the balanced signal output of the 300VSC. The AM25CK properly terminates
the balanced signal lines to the amplifier in the 300GC, 300GCX, 300X, 302GC, 302GCX, 302X and
50GC. As shown in Figure 2 on page 12, connect the white input wires on the AM25CK to the terminals
TB1-4 and TB1-5 of terminal block TB1 on the 300VSC. The AM25CK and AM70CK Connector Kits
are NOT polarity sensitive, but you must observe polarity when placing speakers in close proximity to
each other.
Model 300VSC-1 and Model 300VSC-1044SB SelecTone Command Units
CROSSTALK/INTERFERENCE HAZARD — Mixing power lines with signal
lines can cause cross talk, interference, or hum in the signal lines, which
interferes with the emergency warning capability of this equipment. Do not
install power lines in the same conduit as signal lines.
SHOCK HAZARD — Do not install signal lines in the same conduit with power
lines. Avoid routing signal lines on cable trays with high voltage power lines.
Figure 1 Connections on the back of Model 300VSC
9 10 11 12 13 14 15 16 17
1
TB1
Installation and Maintenance Manual
2 3 4
5 6
7 8 9 10 11 12 13 14 15 16
FROM EXTERNAL
SWITCHING DEVICES
LEVEL CONTROLS
TB2
290A7323
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