Bosch INTELLIVOX DDC LBC 3251/00, Installation Manual

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3. Appendix.
3.1 Reference part list.
Connectors for external wiring.
Table 3 Intellivox external connectors details.
Other installation related accessories.
Table 4 Specific installation related accessories.
Other network related accessories.
Table 5 Specific network related accessories
3.2Grounding strategy.
The ground (GND) terminals on the electronics
module serve different purposes.
1. Safety . The GND terminal located at the mains
IEC connector provides a direct low impedance
path from the metal parts of the chassis to ground.
In conjunction with a proper designed mains
distribution network, this offers extra safety in
situations where the standard class 2 insulation is
not sufficient (fire, moisture etc.). Always connect
the IEC ground terminal.
2.
Reduction of RF emission
. Although the
Intellivox electronics module is well shielded and
external connections are de-coupled to prevent RF
emission from the internal high speed digital
circuits, this protection will not work properly when
the chassis has no solid ground reference.
3. Immunity . The GND terminal shorts currents
which are induced by (RF) fields in the signal
cables effectively to chassis-ground, provided that
the cable shield is of sufficiently low impedance.
To make things even more complex, the RS-485
terminal of the chassis also has a DGND pin, while the
ambient SPL/temperature terminal has both GND and
AGND pins.
The pins labeled GND are connected directly to the
chassis.
The RS-485 DGND pin is not a ground pin, but serves
as a reference for the RS-485 AB and YZ wires.
Although the DGND pin should be connected to the
shielding of the RS-485 cable (when in use), DGND
(and ABYZ) has no relation to GND except for the
fact that the voltage between DGND and GND is
clamped to a maximum voltage of 50 V for reasons of
safety and immunity. In an installation with a
connected network, the RS-485 cable shield must be
grounded at some central position.
• DGND should not be connected to any other
ground pin (GND or AGND) on the chassis.
Intellivox DDC | Installation Manual | Appendix
Bosch Security Systems | July 2003
EN
| 13
Terminal Description Manufacturer Manufacturer code
RS-485 Wago cage clamp connector 5 pin
female 5 mm pitch WAGO 231-105/026-000
Audio input Wago cage clamp connector 6 pin
female 5 mm pitch WAGO 231-106/026-000
Failure, Fan, Ambient
SPL and Temperature Wago cage clamp connector 5 pin
male 5 mm pitch WAGO 231-605
Description Type Number
Intellivox swivel bracket 90° LBC 3270/00
Intellivox swivel bracket 45° LBC 3271/00
Ambient mic. and temperature sensor LBC 3262/00
Description Type Number
Program set
(Adapter cable+RS-232 to RS-485
WinControl CD-Rom) LBC 3260/00