Operating Instructions

Applications
Siemens Building Technologies, Inc. 19
Pneumatic Damper Actuator
If the damper actuator fails due to a leak, then the damper will go to the full open position.
Alarms will be displayed on the ODP indicating unsafe operating conditions.
Venturi Air Valve
If the Venturi Air Valve fails, alarms will be displayed on the ODP indicating unsafe operating
conditions.
AO-P Module
If the AO-P module fails, alarms will be displayed on the ODP indicating unsafe operating
conditions.
Fume Hood Controller: Universal Sash Configuration
with Damper or Venturi Air Valve
Application 941 and Application 942 are designed for use with a wide range of fume hood
sash configurations in a manifolded fume hood exhaust system. The sash configurations
include:
 Bench style fume hoods – single vertical sash
 Bench style fume hoods – 2 to 8 horizontal sashes (multiple widths)
 Bench style fume hoods – combination with 2 to 8 horizontal sashes (multiple widths)
in the vertical carrier
 Walk-in style fume hoods – 2 vertical sashes, one on top of the other
 Walk-in style fume hoods – 2 vertical sashes, with top sash having 2 to 8 horizontal
sashes (multiple widths)
These applications use sash alarms and three face velocity setpoints to limit the air entering
the hood, each fume hood has an individual exhaust damper or valve connected to a central
fan and allows face velocity setpoint changes at the ODP. Application 942 has an optional
Autozero module that automatically calibrates the flow input to the FHC. The application
incorporates special functionality that changes AO2 to a value that more closely matches the
exact measured airflow rather than the setpoint. These applications also modulate the
exhaust air valve or damper based on inputs from the vertical sash sensor(s), horizontal sash
sensor(s), an exhaust airflow sensor, and the controller setpoints.