Operating Instructions
s
en
Operating Instructions
M-bus module WZU-MB G4, WZU-MI
A6V12318596_----_a
2021.01.28
Translation
Siemens Smart Infrastructure A6V12318596_----_a 2021-01-28 4
1. Safety Information
Ensure ESD protection.
Avoid short-circuits on the PCB.
Always route connecting cables through the grom-
mets of the meter.
Do not cut the grommets shorter than necessary
since this may lower the degree of protection.
Disconnect the M-bus voltage during connection
work.
2. Description of functions
The M-bus module is an add-on module for the type UH50..;
Firmware ≥ 5.15 and UC50.. .
The module enables the meter to communicate with an M-bus
center in order to transmit measured values.
These modules are available in 2 types:
• M-bus module G4 (WZU-MB G4)
• M-bus module with pulse inputs (WZU-MI) for connection of
pulse generator
3. Installation and assembly
The meter has two module slots for additional modules.
Number
Description
1
Service button (under the housing cover)
2
Slot “module 1”
3
Slot “module 2”
4
Bushing for power cable
5
Bush sleeves
For connection with the M-bus master or M-bus repeater, 2
flexible cables with a conductor cross-section of 0.25 mm
2
to
0.75 mm
2
are provided, which are to be combined to a multi-
core line.
The outer diameter of the cable must be between 4 mm and 6
mm. All cables have to be routed through the existing bush
sleeves “a” or “b” in the meter. It may be convenient to connect
the cables before the meter in a single multi-conductor cable
on a splitting box.
Installing the communication module
The communication modules are connected via a 6-pole reac-
tion-free connector so that installation or replacement is possi-
ble at any time.
To install a communication module proceed as follows:
• Press the 4 side lugs of the housing cover inwards and
remove the cover.
• Determine the correct slot.
Note: Das WZU-MB G4 module may be fitted on both
slots.
Note: The WZU-MI module can only be used in slot
“module 1”.
• Put the communication module into the correct position.
• Place the communication module carefully in both the guide
slots and push it in.
• To connect an external cable, open the sleeve matching
the cross section of the connection cable.
Note: Open the cable sleeves in such a way that they
enclose the cable tightly.
Note: The circuit of the pulse generator and the M-
bus must be galvanically isolated.
• Guide the cable through the sleeve from outside.