User`s guide

User’s Guide ______________________________________________________________________
50 ___________________________________________________________________M210662EN-A
The heating element in the shaft tunnel keeps the temperature of the
bearings above the freezing level in cold climates. Nominally it
provides 10 W of heating power. It is recommended to use a thermostat
switch in the sensor cross arm for switching the heating power on below
+4 °C.
Introduction to Heated Anemometer
9608-044
Figure 40 Anemometer WAA252
Heated Anemometer WAA252 is designed for environments where a
non-freezing sensor is required. The foil heaters are inserted into each
cup and in the cup wheel hub.
The transmission of heating power to the WAA252's rotor is
contactless, with no slip rings or brushes. This feature eliminates sparks
and excessive friction or wear. Power to the heaters is supplied via a
rotary transformer, with 26 kHz low-EMI sine wave.
Power consumption, typically 72 W, is very low considering the heating
efficiency and the protection against freezing provided.