TEL AFA4000/2, Installation And Operating Manual

Page: 146 / 177

AFA4000/2 Airflow Monitor / p.146
12. Operation: Auto Sash Controller
12.1 Control philosophy
When all components are installed, setup and calibrated correctly, the Auto Sash
Controller closes the sash after a pre-set delay, provided that the area in front of the
fume hood is clear.
The following additional protocols also apply:
•
When the user returns to the fume hood during the delay period, the control timer
will stop and reset once the user leaves the fume hood again.
• When the user returns to a fume hood that is closing, the drive will stop when it
senses the user.
•
When an obstruction is detected under the sash, the Auto Sash Controller will not
open or close the sash and will give a visual alarm to indicate a fault condition.
•
When an obstruction is detected whilst the sash is closing, the sash drive will stop and
give a visual indication to demonstrate a fault condition. To reset the fault alarm,
press the reset button.
•
When the sash starts to close a timer is initiated. When the sash does not close within
the specified time, the sash drive will stop and will give a visual alarm to indicate a
fault condition.
•
When a user is present in front of the fume hood, the sash can be operated by hand.
12.2 Modes of operation
The Auto Sash Controller has the following modes of operation:
• User Present
•
User Not Detected
•
Auto-Open (User Configurable)
• Building Management System (BMS) Inputs
•
Sash Lock