If you wish to use
many
AV102SS intercoms on a site, you may also connect the system
without
any AVPSU4 units as shown in the diagram below.
The advantage of this configuration is that the wiring is easier, as there are no AVPSU4s
to install or connect, no “D” type connectors to wire, and the cables from the intercom
units connect directly into the BINREL02 terminals. The call-button wiring is opto-isolated
only at the intercom end
, and care should be taken when connecting these outputs, as
they are polarity conscious.
The audio signals are transformer isolated at the intercom end, and the BINREL02 has
on-board matching transformers which are switched in and out with the signal switching.
This provides a high degree of protection against unwanted voltage which may appear on
the sites’ audio cabling, and which could otherwise cause damage to the equipment.
The audio transformers also provide both a balanced-line signal path between the
intercom and the AVPSU4 (reducing noise pickup), and a “Ground Lift” which prevents the
familiar “Ground Loop Hum” problem which plagues some installations.
SITE WIRING BETWEEN INTERCOMS AND EQUIPMENT ROOM
DOCUMENT NUMBER AV102SS/OEM/01 REVISION 6.1 1st August 2006 Page
14
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