Recommendation For The Signal Lines; Connecting Signal Lines Of The Selectone System To The 300Scw-1 - Federal Signal SelecTone 300SCW-1 Manual De Instalación Y Mantenimiento

Recommendation for the Signal Lines

REDUCED SOUND OUTPUT — If too small a diameter cable is used, unacceptable
signal voltage drop in the signal line will cause reduced sound output from the
remote signal device. Only use a cable having wire diameter greater than 22 AWG.
The signal lines transfer tone signals and verbal messages from the 300SCW-1 to the remote SelecTone
devices. To reduce the possibility of cross talk, hum, and static noise pickup, the signal lines must be twisted-
pair, shielded audio cable. In the majority of systems, use AWG 18 twisted-pair audio cables. Federal Signal
does not recommend that new or existing telephone lines be used as signal lines in a SelecTone system for
the following reasons:
✓ Interference from other services or systems, or interference from the system to other services
✓ Cross talk, interference, or hum induced by other telephone lines
✓ Extended downtime because of the second party involvement required to service the lines
✓ The additional cost of installation, interfacing devices and monthly charges as opposed to a one-time
cost of performing the installation

Connecting Signal Lines of the SelecTone System to the 300SCW-1

See Figure 2 on page 12. To connect signal lines of the SelecTone system to the 300SCW-1, connect a
color-coded twisted pair of audio cables with conductors no smaller than 18 AWG to 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 need to be considered when calculating how
many speakers can be connected to the 300SCW-1.
CROSSTALK INTERFERENCE — Mixing signal lines with power lines could
cause electrical interference, which could impede or render the system
inoperable. Do not install signal lines in the same conduit with power 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.
Model 300SCW-1 Wall-Mounted Command Unit
Installation and Maintenance Manual
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