Greenheck Vektor Laboratory Exhaust with VGN Technology Electrical Controls Information (476072) - Manual (Page 26)

General Electrical Controls Information
General
Issue Possible Cause Recommended Action
Fan is running but no
pressure is being created
in the duct.
Isolation damper not open.
Check power at isolation damper and determine
if it is open.
Bypass damper maybe open. Verify bypass damper is closed.
Nozzle actuator is not
responding to fan speed
changes.
Sure-Aire transducer not reading air flow.
Inspect pressure tubing to transducer and verify
voltages.
No power at the nozzle actuator. Verify power and signal at the actuator.
Low cfm due to laboratory hoods being
closed. Open all laboratory hoods to verify nozzle
operation.
Unstable fan conditions.
Fan is not balancing
the system and keeps
changing speed.
BMS PID timing is incorrect. Increase time functions in the system.
BMS PID overlap is incorrect.
Create an increased dead band between PID for
fan and bypass.
System has a positive
pressure condition.
Isolation damper not open.
Check power at isolation damper and determine
if it is open.
BMS fan control not working properly.
Check BMS control and determine if condition is
occurring at full speed and bypass is closed.
Duct pressure transducer failure.
Verify power and signal at duct pressure
transducer(s).
Broken fan belt. Check fan belt for failure.
Bypass damper maybe open. Verify bypass damper is closed.
Access panel is missing on fan or bypass air
plenum.
Replace missing access panels.
Nozzle is not operating and is at minimum
area.
Check actuator power and signal.
System has an unfavorable
negative pressure
condition.
BMS fan control not working properly.
Check BMS control and determine if condition is
occurring at fan low speed and bypass full open.
Duct pressure transducer failure.
Verify power and signal at duct pressure
transducer(s).
Bypass damper operation. Verify bypass damper operation.
CFM reading is low or at
zero even though fan is
operating.
Isolation damper is not open.
Check power at isolation damper and determine
if it is open.
Sure-Aire tubing leak or blockage. Inspect tubing and blow out tubing with air.
Sure-Aire tube lines hooked up backwards. Flip the high and low tube lines.
Sure-Aire transducer for system is bad.
Test voltage with meter for 24V and output
signal.
Laboratory hoods are closed in the building Open all laboratory hoods and verify operation.
VGN Factory-Supplied VFD
Issue Possible Cause Recommended Action
Fault on either keypad
display.
Multiple.
Consult VFD manufacturer fault guide for
solution.
VFD is not communicating
to the BMS system.
Multiple. Consult VFD manufacturer communication guide.
VGN Nozzle Controller Customer-Supplied VFD
Issue Possible Cause Recommended Action
Alarm contact on nozzle
controller is “Active”
Velocity is below the required preset value
Fan speed is too low. Not creating enough
airflow. Speed up fan.
Fan is shown as running, but no flow is being
created. Airflow not present. Check flow station and
components.
General System Failure Mode
If the 2-10 VCD signal is lost from the controls and the 24V power is still present, the nozzle actuators will move to the minimum
area position.
If the 24V power is lost from the controls but the 2-10VCD signal is still present, the nozzle actuators will stay in place at the
moment when 24V power was lost.
Troubleshooting
26 VGN Technology
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