Commissioning Instructions

Table Of Contents
Before You Begin
Setting AO2 Range
30
Siemens Industry, Inc. Start-up Procedures 140-1321
Restricted 2015-11-04
Change the flow by commanding EXH VOL STPT and examine the response. If the
airflow oscillates or overshoots significantly, or if the actuator oscillates, reduce the
gain (EXH P GAIN). If it takes too long to reach the setpoint, increase EXH P
GAIN. Try different valuesit should move accurately and with stability. When the
desired performance is achieved, release EXH VOL STPT.
Stabilizing Unsteady Control (Mode 1, 2)
NOTE:
This procedure does not apply to Venturi actuators that are configured to run open
loop.
HI LIMIT and LO LIMIT can be configured to keep the controller from hunting around
the exhaust airflow setpoints.
By increasing the HI LIMIT and decreasing the LO LIMIT, a deadband is set up around
the setpoints. For example, if the values for HI LIMIT and LO LIMIT are set to 1.10 and
0.90 respectively, and the flow is within 10% of setpoint, the airflow PID loop stops
controlling and leaves the actuator in its last position. Active control resumes once the
flow leaves the deadband. (Setting both points to 1.0 disables this feature. Setting LO
LIMIT greater than or equal to HI LIMIT also disables this feature.)
Set HI LIMIT and LOW LIMIT to the desired values.
Setting AO2 Range
1.
Set REPORT to
AIRFLOW IN
.
2.
Do one of the following:
For a single Fume Hood wired to an LRC:
Set AO2 RANGE to the maximum expected flow for the fume hood, plus
approximately 10%. For example, if the maximum flow is 900, set it to
1000.
For two to six Fume Hoods wired to an LRC using a Fume Hood
Averaging Module:
Set AO2 RANGE to the maximum expected flow for the largest fume
hood, plus approximately 10%.
The AO2 RANGE point must be set to the same value for all fume hoods
connected to the Fume Hood Averaging Module.
AO2 is now active and a proportional 1 to 10V signal can be read on
AO2.
3.
Set AO2 DEADBAND to the desired value.