Can-Bus; Ems Bus - Bosch Compress 3400i AWS Installation Manual

Installation
Coding switches A and P must not be adjusted! Otherwise malfunctions
and faults will occur.
Important: check the coding when a replacement part is used ( Fig.
36).
5.7.3

CAN-BUS

NOTICE
Malfunction due to faults!
Power circuit cables (230V~) cannot be near any CAN-BUS, sensor and
other signal circuit cables (12V DC).
▶ Ensure there is a minimum distance of 100 mm between power
circuit cables and CAN-BUS, sensor and other signal circuit cables.
CAN-BUS: do not connect 12V direct voltage output "Out 12V DC" on the
installation module.
NOTICE
Mixing up the 12V and CAN-BUS connections will result in a system
fault!
The communication circuits are not designed for a constant voltage of
12V.
▶ Make sure that both cables are connected to the correspondingly
marked connections on the printed circuit board (CAN high / CAN
low).
The outdoor unit and indoor unit are connected to each other via a
communication cable, the CAN-BUS.
2
A LIYCY cable (TP) 3x0.75 mm
extension cable outside of the unit. Alternatively, twisted pair cables
approved for outdoor use with a minimum cross-section of 0.75 mm
can be used. One of the shielded ends must be connected to the nearest
grounding terminal in the indoor unit structure. The other end cannot be
connected to the grounding or any metal part of the outdoor unit
structure.
The maximum permissible cable length is 30 m.
The Can Termination Switch marks the start and end of the CAN-BUS
connection. Make sure that the right boards are terminated and that all
other boards within the CAN-BUS connection are not terminated.
16
(or equivalent) is suitable as an
Fig. 12 CAN-BUS connection
[1] Indoor unit
[2] Outdoor unit
2
5.7.4

EMS BUS

NOTICE
Malfunction due to faults!
Power circuit cables (230V~) cannot be near any EMS-BUS, sensor and
other signal circuit cables (12V DC).
▶ Ensure there is a minimum distance of 100 mm between power
circuit cables and EMS-BUS, sensors and other signal circuit cables.
The control unit is connected via the EMS-BUS to the installer module of
the indoor unit.
The control unit is supplied with power via the BUS cable. The polarity of
the two EMS-BUS cables is irrelevant.
The following applies to accessories that are connected to the EMS-BUS
(see also the installation instructions for the respective accessories):
▶ If several BUS units are installed, there must be a minimum spacing of
100 mm between them.
▶ If several BUS units are installed, connect them in parallel or in a star
configuration.
▶ Use cable with a minimum cross-section of 0.5 mm
▶ In case of external inductive interferences (e.g. from PV systems),
use screened cables. Connect only one end of the cable shield to the
nearest ground.
Out 12V DC
CAN high
CAN low
gnd
GND Can L Can H N L
2
Compress 3400i AWS – 6721852066 (2023/01)
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0010036947-001
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