The Isolator Boards are daisy-chained in the loudspeaker loop. Their main function is to:
–
detect and isolate short circuits in the adjacent section.
–
detect and isolate open circuits, short circuits, and overloads on a tap-off.
These functions can be configured with jumper settings.
The Isolator Board can be mounted inside the included IP30 housing or in Bosch loudspeakers
that have mounting provisions for loudspeaker or line supervision. A test button and LED
indicator on the Isolator Board are used to check if the Isolator Board and loudspeaker cable
(including polarity) are correctly connected.
PM1‑LISD - Loudspeaker DC Blocking Board
Referred to in this manual as DC Blocking Board:
The DC Blocking Board blocks DC and provides overload protection by current limiting. It has
the same connections as the Isolator Board, which allows for quick and convenient connection
of the loudspeaker loop and tap-off connections (maximum 20 watt loudspeaker load). The DC
Blocking Board can be mounted inside Bosch loudspeakers that have mounting provisions for
loudspeaker or line supervision.
Loudspeakers Line Isolator System
System overview | en
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Bosch Security Systems B.V.
Installation and Operation Manual
2014.03 | V1.1 |