Defined Modes - Greenheck Vektor Installation, Operation And Maintenance Manual

General Electrical Controls Information
Fan Operation - Multiple Fans, With Staging
Definition of typical operation modes:
Mode #1: Unoccupied. Defined as no one inside the
lab(s), all lab hoods are closed.
1. Fan(s) will operate at BMS required speed and nozzle
will modulate as necessary to achieve the required
velocity out the fan(s). BMS to monitor nozzle
actuator feedback for each fan and keep fan speed
above the minimum required to maintain velocity.
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 #2: Occupied; no lab hoods being used.
Defined as people entering the lab(s), no work being
done at the hoods.
1. Fan(s) will operate at BMS required speed and nozzle
will modulate as necessary to achieve the required
velocity out the fan(s). BMS to monitor nozzle
actuator feedback for each fan and keep fan speed
above the minimum required to maintain velocity.
2. Sure-Aire will measure airflow of the fan. VFD or the
nozzle controller 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.
4. VFD speed, duct pressure control and the bypass
damper(s) operation is provided by the BMS system.
Mode #3: Occupied; some or all lab hoods being
used. Defined as people in the lab(s), lab hood sashes
being used.
A. Sashes opening 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 increase fan speed and increase nozzle open
area. Additional fans may be added as necessary.
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.
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VGN Technology
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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 speed and decrease nozzle
open area. Removal of fans may be required as
necessary.
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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