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Siemens
Ultrasonic heat and cooling energy meters UH50..
CE2N5324en
Building Technologies
2013-01-14
In addition to the M-bus connection facility, the WZU-MI module has 2 pulse inputs
for the connection of metering pulses from hot and cold water meters with Reed
contact, relay or open collector. The cumulated volume is calculated based on the
pulses and the set pulse valency, stored in the processor unit at 5-minute intervals
and passed on via M-bus.
The volume values calculated by the meter from the pulse inputs are not
capable of being officially calibrated.
In addition to possible power supply from the M-bus connection, the WZU-MI mod-
ule is equipped with a battery. It powers the module processor and the pulse input,
if no M-bus voltage is applied.
As pulse transmitters for the pulse inputs, either isolated contacts (e.g. relay or
Reed contacts) or electronic transmitters (open collectors) can be used.
If an open collector circuit is used as the transmitter of the pulse inputs, the cable
must always be electrically isolated from the M-bus inputs of the MI module.
The analog module (WZU-AM) converts the measured value from the heat meter to
an analog signal. Each module has 2 channels whose functions can be configured
independently.
Parameterization (selection of measured value and output range) is performed with
the service software.
The output signal is refreshed at 4-second intervals.
The analog module can be plugged into any of the 2 sockets. Both modules can be
used concurrently.
The module must be powered via an external power pack (e.g. NZR-NE).
The 2 cables of the power pack are interchangeable.
If 2 analog modules are used, they can be powered by the same power pack. If the
meter is mains-powered (AC/DC 24 V), the module(s) and the meter can be con-
nected to the same power outlet. In this case, the wires must be bridged on the
module. The connection terminals on the meter’s power pack are not suited for that
purpose.
If a meter is used with an analog module, a D-cell is required – if battery-powered.
M-bus module WZU-MI
with 2 pulse inputs
Function data
Note
Analog module
WZU-AM
Function data
Note
Power supply
RF module, 433 MHz,
WZU-RM