Greenheck Vektor Installation, Operation And Maintenance Manual page 7

General Electrical Controls Information
B. Sashes closing in the lab
1. Fan(s) will operate at BMS required speed and
nozzle will modulate as necessary to achieve the
required velocity. Typical system response should
be to decrease fan(s) speed and decrease nozzle
open area.
2. Sure-Aire will measure airflow of the fan. VFD or the
nozzle controller for each fan will report this value
to BMS.
3. Duct pressure control, by the BMS, will modulate
bypass damper(s) as required.
Note: Follow bypass damper(s) operation
depending on number of fans running.
4. VFD speed, duct pressure control and the bypass
damper(s) operation is provided by the BMS
system.
Mode #4: Fault Mode. Defined as safety mode;
the system has an issue and needs to default to VFD
bypass.
1. VFD failure detected, automatically or manually put
into VFD bypass if available by operator or BMS.
2. Nozzle area to increase proportional to fan airflow
which will increase as fan speed is at maximum.
3. Sure-Aire will measure airflow of the fan. VFD or the
nozzle controller for each fan will report this value to
BMS.
4. Duct pressure control will modulate bypass
damper(s) as required if system is in alarm mode.
Duct pressure control is provided and programmed
by the BMS system.
5. System manually to be reset and placed back in VFD
auto mode.
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