Commissioning Instructions

Before You Begin
Setting AO2 Voltage Minimum
16
Siemens Industry, Inc. 140-1318
Restricted 2015-11-04
Setting AO2 Voltage Minimum
This section can be skipped, if the FHC is connected to a room controller or field panel
from Siemens Industry, Inc.
This function allows the minimum voltage to be set to a value other than 1 (default).
The minimum voltage is output when the flow is equal to 0 cfm.
Set AO2 V MIN to the desired value.
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.
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”.
The digital output DO6 can be used for local indication that the sash was opened after
the hood entered Out of Service mode. The output will remain ON until STARTUP
MODE is changed.
Loop Tuning Procedures
Set REPORT to TUNING.
General Information
The FHC uses one Proportional, Integral, and Derivative (PID) loop. It is similar to the
LOOP in a PPCL statement except gains are smaller by a factor of 1000. The process
variable (PV) is EXH VOL. The setpoint is EXH STPT. The control variable (CV) is
DMPR CMD.
You can evaluate loop performance and do loop tuning by observing the display at the
Operator’s Display Panel. The displayed face velocity is related to the exhaust flow,
which is directly controlled by the loop.
However, the most reliable way to evaluate loop performance is to collect trend data on
the exhaust volume and the exhaust setpoint.
When using the Operator Display Panel for loop evaluation or tuning, set DISPLAY WT
to 100%.