Siemens 125-5033 - Manual (Page 13)

Product Overview
Siemens Building Technologies, Inc. 5
Pressing the Emergency Purge button a second time reverts the Fume Hood Controller to
normal operation for the current conditions.
HI/LO: HI/OFF Select button – Pressing this button changes the controller from a high flow
setpoint to a low flow setpoint and back again or changes the controller from a high flow
setpoint to and OFF state and back again.
Auxiliary Button – The Auxiliary buttons are not used currently.
For more information on the ODP, see the Fume Hood Controller Operator Display Panel
User's Card (125-1976).
Figure 4. Operator Display Panel.
Laboratory Exhaust Air Terminal
The Laboratory Exhaust Air Terminal is a pre-packaged, easy to install, airflow measurement
and control station. See Figure 5. It combines an orifice plate flow sensor, differential
pressure transmitter, an electronic actuator assembly, or No. 3 pneumatic actuator, and
Analog Output-Pneumatic (AO-P) Module, and butterfly damper in a 20 gauge 316 stainless
steel duct section.
This arrangement provides fast acting, stable, and precise VAV fume hood exhaust airflow
control.