5
Troubleshooting
These procedures cover only the most common problems you may encounter. Refer to your RA-20R rotary
atomizer manual, valve manual, or turbine manual for more information. If you cannot solve the problem with the
information in your manuals, contact your local Nordson representative for help.
Problem
Possible Cause
Corrective Action
Poor coating material
transfer efficiency
Workpieces not properly grounded
Poor coating material formulation
Booth air flow too high or too low
Power supply or control unit defective
Defective high-voltage cable or IPS cable
Defective charge ring
Poor connections
Check the workpiece-to-ground resist-
ance.
Check the coating material.
Adjust the air flow.
Check the power supply output.
Check cable resistance or continuity.
Check the charge ring resistance.
Check all electrical connections.
Coating material wraps
back on atomizer
Spray booth air velocity too low
Vector air pressure too low
Poor coating material formulation
No grounded part in front of atomizer
Increase air flow through booth.
Increase vector air pressure.
Check coating material.
Reprogram system controls.
Poor coating material
atomization
Turbine speed too low
Cup assembly plugged or damaged
Coating material viscosity incorrect
Flow rate too high
Coating material not charging
Increase turbine speed.
Clean and inspect cup assembly.
Change material viscosity.
Lower flow rate.
Check electrostatic system.
Turbine will not rotate,
rotates slowly, or
oscillates
Turbine or bearing air pressure low
Leaking O-ring in transition plate
Turbine air regulators not set properly
Turbine air bearings worn or plugged
Cup out of balance or damaged
Check turbine and bearing air pressure.
Remove turbine and replace O-ring.
Check regulator settings.
Repair or replace turbine.
Check cup, replace if necessary.
No turbine speed
control or display
Defective transmitter assembly
Defective fiber-optic cable
Defective fiber-optic module
Defective display or control unit
Check transmitter output.
Check cable output.
Check module output.
Repair or replace defective component.
No spray when coating
material turned on
Nozzle or fluid tube plugged
Fluid tubing plugged
Valve trigger air pressure low
Valve adjusted incorrectly or malfunction-
ing
Trigger air switch or solenoid defective
Clean or replace nozzle or fluid tube.
Check tubing for blockage.
Check trigger air pressure at valve.
Repair or replace valve.
Repair or replace component.
Pattern cannot be
shaped, no vector air or
pressure low
Vector air tubing kinked or plugged
Leaking O-ring in transition plate
Leak in charge ring or front shroud
Vector air slots plugged
Resistor sleeve installed incorrectly
Valve or regulator malfunction
Repair or replace tubing.
Remove turbine and replace O-ring.
Replace O-rings or duckbill seal.
Clean air slots in charge ring.
Install sleeve correctly.
Repair or replace component.
Material keeps flowing
when valve is closed
Valve worn or jammed open
Switch or solenoid valve defective
Repair or replace valve.
Repair or replace component.
Material leaking from
valve weep holes
Valve seals worn
Repair or replace valve.
