22
Advance Optima Ex Analyzer Modules Operator’s Manual
42/24-12-2 EN
Connect the System Bus,
continued
Zone 1 System Bus
Extension Cable
The yellow system bus cable should not be used for system bus extension in
Zone 1, that is to connect the connection box and isolation relay -K01 in the CU-Ex.
Instead, a shielded 4-conductor cable with twisted pairs and a wire section
≥
0.5 mm
2
should be used (part number 24009-4-0059201).
The unused conductor should be
•
connected to a PE (potential compensation) terminal in the connection box
•
Securely attached at a distance of > 8 mm from current-bearing components in
the CU-Ex
Connect the system bus extension cable shield to the metal threaded cable
connections on the connection box and (Ex) central unit.
Zone 2 System Bus
Cable
The standard system bus cable (wire section of 0.24 mm
2
) can be used in Zone 2
since in normal operation the system bus is not ignition capable per EN 50021.
Terminating Resistor
The Ex analyzer module comes with a terminating resistor but it is not connected.
Therefore at the last analyzer module the “BUS END LOW” and “BUS OUT LOW”
as well as “BUS END HIGH” and “BUS OUT HIGH” connections must be inter-
connected (see e.g. Figure 4, Page 17).
At the other analyzer modules the “BUS END LOW” and “BUS END HIGH”
connections should be joint at a PE terminal.
These connections are always made in the connection box so that the Ex analyzer
module does not have to be opened, even for expansion or maintenance purposes.
In the (Ex) central unit the terminating resistor is installed in the electronics module.
Total Length
The total length of the system bus wiring should not exceed 350 meters.
