Commissioning Instructions

Before You Begin
AVS FAILMODE
15
Siemens Industry, Inc. 140-1318
Restricted 2015-11-04
AVS FAILMODE
AVS FAILMODE is a point that describes how the Venturi Air Valve will respond if the
Air Velocity Sensor (AVS1) fails.
Set AVS FAILMODE to the desired value.
AVS1 failure and AVS FAILMODE values.
AVS FAILMODE
OPEN
(default)
Exhaust fails Open
HOLD Exhaust Holds current Position
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.
NOTE:
AO2 DEADBAND can be set from 0 to 102% in 0.4% increments. 0% will give the
actual flow all the time. This signal may be too bouncy to give a stable output and will
cause short-term room instability during fume hood sash movements. A 10%
deadband is equal to ±5% of the flow. Any value over 100% will turn the feature off
and revert to standard control.
For stable pressure reading, lower the AO2 DEADBAND. For unstable pressure
readings, raise the AO2 DEADBAND until the output signal stabilizes.