Commissioning Instructions
Table Of Contents
- Before You Begin
- Verifying Power
- Verifying Slave Mode Application Number
- Setting Controller Address
- Setting the Application
- Setting Display Units
- Testing the Operator Display Panel
- Setting Duct Area
- Setting Airflow Sensing Input
- Setting Flow Coefficients
- Automatic Calibration Option
- Setting Blank Display
- Setting Display Weight
- Setting Display Resolution
- Setting High Flow Setpoint
- Setting Low Flow Setpoint
- Setting ODP Display
- Setting Hi and Low Warn Limits
- Setting Hi and Low Alarm Limits
- Setting Alarm Timer
- Setting Emergency Setpoint
- Setting Emergency Timer
- Setting Damper Control
- Checkout of Damper
- (Optional) Setting Airflow Input Type
- (Optional) Calibrating the DP Transmitter without an Autozero Module
- (Optional) Calibrating with an Autozero Module
- AVS FAILMODE
- Setting AO2 Range
- Setting AO2 Voltage Minimum
- Start-up/Decommission Mode
- Loop Tuning Procedures
- Flashing Controller Firmware
Before You Begin
Loop Tuning Procedures
17
Siemens Industry, Inc. 140-1318
Restricted 2015-11-04
Loop Time
Commanding LOOP TIME controls the speed of the loop calculations. The value of
LOOP TIME controls how often the loop calculations are performed. The default value
is 0.1 seconds and can be increased to slow the response of the system.
Steady State Performance
Steady state performance is the ability of the loop to maintain its setpoint. Variation of
the EXH VOL from setpoint (with the sash position fixed) can be a sign of poor loop
tuning. However, if the exhaust flow measurement is very noisy, even with a perfectly
tuned loop, the exhaust volume display may still fluctuate.
To distinguish measurement noise from control loop hunting, set the DMPR CMD
output to a fixed value (0%). This locks the actuator; any remaining variation is
probably measurement noise.
Remember to release DMPR CMD when you are done.
Dynamic Performance
Dynamic performance is the speed and the overshoot involved in the response of the
face velocity to a movement of the sash. The face velocity display should return to
within 10% of the setpoint in three seconds or less with minimal overshoot.
Setting P-Gain
The loop should work well with P-only control. For any steady-state flow, the loop
output settles at 0% to maintain the actuator at a fixed position.
Trial and Error Method
If the loop responds too slowly to sash movement, double the EXH P GAIN and
reevaluate it.
If the face velocity overshoots a lot or swings back and forth after a sash movement,
decrease the EXH P GAIN and reevaluate it again.
Exhaust Flow Accuracy Verification
This section presents the steps for verifying the exhaust flow accuracy.
NOTE:
It is recommended that this procedure be performed with the balancer so that the flow
coefficient is coordinated with the measured exhaust flow.
Verify the exhaust flow as follows:
1. Move the sash to an open position. Using a hand-held air velocity meter, perform a
grid measurement of the face velocity. (Divide the face of the fume hood into 1’ × 1’
squares.) Calculate the average face velocity as shown in Figure
Grid
Measurement of Face Velocity
.