Technical data

Chapter 4: Installation
Series SPB Audio Boosters Manual, Revision A
4-8
4.2.4 Installing Audio and Auxiliary Input Connections
The audio input circuit (AUD IN) consists of either the power limited 1V, 25V, or 70.7V circuit
of the SP40S panel. The input uses a blocking capacitor for DC supervision. The audio return
(AUD RET) can be used to link other Series SPB Audio Boosters to the host voice evacuation
panel, additional speakers powered by the host panel, or connecting the host panels 1/2W 1/2W
EOLR.
The auxiliary input circuit is used to trigger the Series SPB Audio Booster to return to full power
from a reduced power mode when operating on the backup battery supply. The input can be
selected to be a power-limited, 8-33VDC NAC circuit or a contact closure. This is selected by
switching SW3. The AUX RET is used to link additional Audio Boosters to the Auxiliary Circuit
or connecting the host panel’s 1/2W EOLR.
Audio Input and
Alarm Mode
Figure 4-5 Audio and Auxiliary Input Connections
1. Connect the audio output from the voice evacuation panel to the AUD IN terminals.
Connect the SP40S panel’s 1/2W EOLR to the AUD RET terminals.
2. Select the proper audio input voltage, using jumper J4 (Input Voltage Select). Location of
the jumper is shown in Figures 4-25 through 4-27.
3. Connect the NAC or Contact Closure input to the AUX IN terminals. Connect the voice
evacuation panel’s 1/2W EOLR to the AUD RET terminals.