PRAESENSA
Installation wiring | en
41
Bosch Security Systems B.V.
Underwriters Laboratories Listing Document (ULLD)
2021.12.21 | V0.15b | F.01U.402.882
Dual Class B wiring (A + B)
+
+
D
(EOL-US)
Figure 3.4:
Dual Class B wiring
If loudspeaker line redundancy is needed, then follow the procedure below to connect two
loudspeaker lines, one to output A and one to output B. Typically the loudspeakers are
mounted alternating A, B, A, B, and so on, half the number connected to A, half the number
connected to B.
1.
Connect half of the loudspeakers in parallel in a loop‑through fashion to output A.
Observe polarity.
–
Follow the same wiring procedure as for using a single line.
2.
Connect an end-of-line device to the end of loudspeaker line A.
3.
Repeat this procedure for the other half of the loudspeakers and connect them to output
B.
4.
Connect an end-of-line device to the end of loudspeaker line B. Loudspeaker lines A and
B must be separately supervised, each with its own end-of-line device. In case of a short
circuit in one of the loudspeaker lines, the amplifier will diagnose the overload condition
to find the affected loudspeaker line and switch‑off that line, so the other loudspeaker
line can continue operation.
