Troubleshooting - Greenheck Vektor Installation, Operation And Maintenance Manual

General Electrical Controls Information

Troubleshooting

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