User Manual

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Siemens Flow switch QVE1902.0.. CM1N1596en
Building Technologies 2017-02-16
Commissioning notes
The switching unit is factory set as a make contact, i.e. the reed contact opens if
the set switching point is breached.
Type of contact Setting Flow rate Electric contact
NO
(closer)
RED arrow
increasing closing
decreasing opening
NC
(opener)
WHITE arrow
increasing opening
decreasing closing
The setting can be changed as needed by the customer:
· Loosen the locking screw (Phillips-head screw) and position the switching unit
until the red or white arrow are visible at the entry of the switching contact guide
for a desired normally open (NO) or normally closed (NC) contact respectively.
· You can use the arrow length to make fine adjustments to the switching point:
Adjust to the arrowhead means: Switching point is at a lower flow rate.
Adjust to the arrow end: Switching point is at a higher flow rate.
· Carefully retighten the locking screw.
· We recommend using thread locker to secure the locking screw on the switching
unit after carrying out individual adjustments.
NO contact (red arrow) NC (white arrow)
Operating notes
· Please make sure that there are no external magnetic fields in the immediate
vicinity of the flow switch, since these can impair device operation.
· Ensure that the maximum operating pressure is not exceeded.
Service notes
· Never remove a flow switch or its body from a system under pressure.
· The flow switch is maintenance-free and cannot be repaired by the user.
Contact type factory
setting
NO or NC contact
Setting the
switching unit