HP GRACO OR PRO TI1681A - Manual (Page 34)

Troubleshooting
34 309293J
Troubleshooting
Voltage Loss Troubleshooting
Normal spraying voltage for a system using the water-
borne gun is 45-55 kV. The system voltage is lower due
to spraying current demands and voltage isolation sys-
tem losses.
A loss of spraying voltage can be caused by a problem
with the spray gun, fluid hose, or voltage isolation sys-
tem, since all of the system components are electrically
connected through the conductive, waterborne fluid.
Before troubleshooting or servicing the voltage isolation
system itself, you need to determine which component
in the system is most likely causing a problem. Possible
causes include the following:
Spray Gun
• Fluid leakage
• Dielectric breakdown at the fluid hose connection or
fluid packings
• Not enough air pressure for the turbine
• Faulty power supply
• Excessive overspray on gun surfaces
• Fluid in the air passages
Waterborne Fluid Hose
• Dielectric failure of hose (pin-hole leak through
PTFE layer)
• Air gap in the fluid column between the gun and iso-
lated fluid supply, causing a low voltage reading on
the isolation system voltage meter.
Voltage Isolation System
• Fluid leakage
• Dirty interior
WARNING
Electric Shock Hazard
Installing and servicing this equipment
requires access to parts which may cause
an electric shock or other serious injury if
the work is not performed properly. Do not install or
repair this equipment unless you are trained and
qualified.
Follow the Fluid Voltage Discharge and Grounding
Procedure on page 20 before checking or servicing
the system and whenever you are instructed to dis-
charge the voltage.
WARNING
Pressurized Equipment Hazard
To reduce the risk of an injury, follow the
Pressure Relief Procedure on page 20
before checking or servicing any part of the
system and whenever you are instructed to
relieve the pressure.