FISCHER DE44, Operating Manual

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If the device is intended for outdoor use, we rec-
ommend permanently protecting the membrane
keypad against UV radiation and using a suitable
enclosure or at least the erection of a sufficiently
dimensioned canopy as a protection measure
against constant rain or snow.
4.1 Process connection
•
By authorized and qualified specialized person-
nel only.
•
The pipes need to be depressurized when the
instrument is being connected.
•
Appropriate steps must be taken to protect the
device from pressure surges.
•
Check the suitability of the device for the media
to be measured.
•
Check that the pressure connections do not
leak before commissioning.
•
Maximum pressures shall be observed.
•
Do not blow into the pressure connections!
The pressure connections are marked with (+) and
(-) symbols on the device. For differential pressure
measurements, the higher pressure is connected to
the (+) side and the lower pressure to the (-) side of
the device.
The pressure measuring lines must be installed on
a gradient so that no air pockets e.g. for liquid
measurements, water pockets or for gas measure-
ments can be created. If the required incline is not
reached, water and/or air filters need to be installed
at suitable points.
The pressure sensing lines need to be kept as short
as possible and installed without sharp bends to
avoid interfering delay times.
If the pressure sensing lines are already
pressurised at the time of commission-
ing, zero-point control and adjustment
cannot be performed. In such cases, the
device should be only connected to the mains with-
out the pressure sensing lines.
4.2 Electronic connection
•
By authorized and qualified specialized person-
nel only.
•
The electrical connection of the device shall be
performed according to relevant VDE and local
electricity board regulations.
•
Disconnect the system from the mains before
connecting the device.
•
Add a fuse adapted to the energy requirements.
Connector 1: Power supply and output signal
Connector 2 : Switching outputs
The nominal supply voltage and the permissible
range can be found in the technical data.
The admissible load / resistance for the signal out-
put is stated in the technical data.
The connection "Signal ground
“(-Sig) is connected
internally to the supply ground. It only serves as the
ground connection for the output signal. This means
that the output signal is free of interference levels
on the power supply lines.
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