Safety Ground - Bosch PRAESENSA Manual

48 en | Installation wiring
Parts check and identification
3.5.4

Safety ground

Connecting the chassis ground screw to safety ground is mandatory for the PRAESENSA
power amplifiers:
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2021.12.21 | V0.15b | F.01U.402.882
The safety ground connection is needed for safety because of high internal voltages. All
PRAESENSA 19"‑devices have a chassis ground screw on the rear panel, which can be
used for a wire connection to the rack frame. The rack frame must be grounded to safety
ground. This is a conductive path to ground or earth that is designed to protect persons
from electrical shock by shunting away any dangerous currents that might occur due to
malfunction or accident. Use a thick, multi strand wire (>2.5 mm
washers for a solid connection.
The safety ground connection is needed as reference for the ground short detection
circuit. Without this connection, the amplifier could be electrically floating and no ground
shorts or leakage currents would be detected for loudspeaker lines that touch ground
Underwriters Laboratories Listing Document (ULLD)
A Amplifier
B 2‑pole screw plug (x2)
C 6‑pole screw plug (small)
D 4‑pole screw plug (large, x8)
E Wire‑end ferrules (small, x12)
F 2‑conductor cable (x2)
G 6‑conductor cable
H Wire‑end ferrules (large, x8)
2
) with wire eyelets and
Bosch Security Systems B.V.
PRAESENSA