Procedure
12
52 ASVxxx
pressure, i.e. do not connect the (
–) hose. Note down the measured duct
pressure in the service report. If the pressure is too low, check whether the
damper is properly closed.
If the damper is completely closed but the duct pressure is still too low,
check the current operating status of the ventilation system.
3.5
Zero adjustment of the differential pressure transmitter in the ASV and comparison of the
measured value
Loosen the supply hoses on the compact controller and make sure the
ends of the hoses or the connectors are not exposed to air flow. Then
select the “Zero adjustment” function in the CASE VAV software.
After that, reconnect the hoses, the ASV and the pressure gauge to the T-
hose. To do this, make a branch of the (+) hose and the (
–) hose to the
external measuring device. At 50% damper position, carry out calibration
measurement using the angle of rotation identified in step 3. Compare the
value measured by the external pressure gauge to that of the ASV and
note them down.
Only use certified measuring equipment.
Observe the stated error of the measuring instrument and note it down
along with the recorded measured value.
If there are still measured values outside the tolerance range, make a
control measurement at local atmospheric pressure. To do this, remove
the hoses again and select the “Online values” option in CASE VAV.
Compare the measured value with the calibration device. Note down the
results in the service report.
Leave the external testing equipment connected to the T-hose and the
VAV for step 6.
3.6
Measuring the volume flow at
max
and
min
In manual CASE VAV mode, set the maximum and then the minimum
volume flow via the VAV box. Compare the online values and those of the
external test equipment to the values stated in the commissioning
certificate. If the values are outside the specified tolerance range, check
the direction of operation of the actuator. Then repeat the measurement.
Another action is to compare the c-factor of the VAV box to the value set in
CASE VAV. If there is a change, note it down. Then remove the external
pressure gauge and return the VAV to operating status and check the
measured values at
max
and
min
again.
