Application

Sequence of Operation
Minimum Exhaust Mode
20
Siemens Industry, Inc. Application Note 140-1344
Restricted 2015-11-09
If specific information about the voltage at low flow is known, that would be entered into
point 1 which is reserved for information about low flow. See Example 2.
Point
Flow
Volt
1 300 7.0
2 0 10.0
3 0 10.0
15 0 10.0
16 1200 0.0
Example 2 - Table with Voltage End Limits and Low Flow Value
You can also manually populate the table with additional values as shown in Example
3 below. In this case, the table becomes indistinguishable from a table generated via
the calibration process.
Point
Flow
Volt
1 300 10
2 340 7.0
3 390 5.8
4 521 4.9
5 531 4.1
6 598 3.8
7 691 3.5
8 798 3.2
9 1200 3.0
10 0 0
16 0 0
Example 3 - Multi-point Table
NOTE:
Since
PID Only Mode
uses PID without a Venturi table and
Open Loop Mode
uses
Venturi table without PID, these two modes cannot be used at the same time.
Minimum Exhaust Mode
If, as the open sash area is decreased, the calculated exhaust airflow setpoint, EXH
STPT, falls below the minimum exhaust airflow specified in EXH MIN, then EXH STPT
is set equal to EXH MIN. Under this minimum flow condition the ODP displays the
closed status instead of the average face velocity.