Application

Sequence of Operation
Start-up/Decommission Mode
24
Siemens Industry, Inc. Application Note 140-1344
Restricted 2015-11-09
Emergency Purge Schedule.
NOTE:
Norm
= Normal operation in which control is at the EXH STPT.
EMER STPT
= EXH STPT increased by the value (%) of EMER STPT.
MAX
= Maximum flow, where the damper is controlled to fully opened.
Start-up/Decommission Mode
The Fume Hood Controller contains different modes controlled by STARTUP MODE
(default is 3). These modes of operation allow the controller to be started up without
the sound of nuisance alarms at the hood. These modes are useful at different stages
of construction and after decommissioning.
The FHC also contains decommission modes and allow some or all of the functionality
of the controller to be turned off.
The modes are described as an enumerated point:
STARTUP MODE
Mode
Description
0 Normal The controller is fully functional.
1 Decommission The controller is fully functional, except the flow
setpoint is set to 0, alarming is limited and the ODP
displays “Out of service” and “OFF”. If the sash is
opened, control is returned and you are notified that
the hood is “Out of service”.
2 Non-functional
Decommission,
closed
The controller is fully functional, except the flow
setpoint is set to 0, alarming is limited and the ODP
displays “Out of service” and “OFF”. If the sash is
opened, nothing changes.
3
(default)
Non-functional
Startup
The controller is fully functional, except alarming does
not work and the ODP displays “Controller – Startup”
and “OFF”.
To enter modes 1 and 2, the fume hood sashes must be in the closed position, and
FACE AREA must be smaller than UN ALRT AREA.