Greenheck Vektor Laboratory Exhaust with VGN Technology Electrical Controls Information (476072) User 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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