Voltage Loss Troubleshooting - Graco HydroShield WMBL00 Instructions - Parts Manual

Troubleshooting
Voltage Loss Loss Troubleshooting Troubleshooting
Voltage Voltage Loss Troubleshooting
Normal spraying voltage for a system is 45-55
kV. The system voltage is lower than the rated
voltage due to spraying current demands and normal
isolation system losses.
A loss of spraying voltage can be caused by a
problem with the spray gun, the fluid hose, or the
voltage isolation system, since all of the system
components are electrically connected through the
conductive, waterborne fluid.
Note
It is important to keep the inside of the
isolation cabinet clean. If the exterior of the
isolation fluid pump (K), the isolation valve
connecting rods (225), or plastic walls of the
cabinet (9) are dirty, voltage will be lost along
those paths.
1. Check the isolation system for fluid leaks as
described in Check for Fluid Leaks, page
2. Check for connections between high voltage
components and grounded components
within the isolation system. The figure in
Troubleshooting HydroShield Voltage, page
77 identifies the high voltage, the isolation, and
the grounded components.
3. Verify that the inlet air supply pressure is above
the minimum required 70 psi (0.5 MPa, 4.8 bar)
and the inlet air status bar is green. The air
inlet field appears on the Home screen. See
Home Screen, page
4. Follow the troubleshooting procedure listed in the
spray gun manual 3A7504.
5. Dispense enough fluid to expel any air pockets
from the fluid line.
6. Verify that the electrostatic shield (12) is in place,
and then close and latch the cabinet door.
76
68.
45.
7. Put the system in Spray mode. Trigger the gun
with the electrostatics on by turning the ES
ON/OFF valve to the ON position. Look at the
Volt Level display on the Home screen to see the
spraying voltage. Under normal conditions, the
spraying voltage should be between 45 and 55
kV. If the display shows 0 kV then continue with
the next step. If the voltage is above 0 but lower
than expected, continue with step 10.
8. If the system is completely shorted out (0 kV)
the fault may be with the mechanical operation
of the isolation valve, grounding rod, or door
switch. Open the cabinet door and go to the
maintenance screens on the control interface.
• Activate the shuttle down and shuttle up valves
and verify that the shuttle travels up and down
smoothly. See Maintenance 3: Shuttle Valve
Resets and Test, page 61
shuttle.
• Activate the ground rod and make sure the
cylinder is retracting fully. (See
Misc Valve Resets and Test, page
cylinders are working properly, then continue
with the next step.
Note
For the ground rod to activate, either
the cabinet door must be closed or
the door switch must be manually
switched.
9. Verify that the door switch is working
properly. Follow the procedure in
Check the Door Switch, page
10. If the kV is low, verify the accuracy of the kV
meter. Use a high voltage measurement probe
to measure the kV at the spray gun electrode.
The readings should be within a few kV. If they
are not, proceed to the next step.
11. Leakage internal to the isolation fluid pump could
also cause voltage loss. Check the pump weep
holes (WH) in the middle housing (307) for fluid
leaks. Service the pump if needed.
12. If voltage is still low, retest the gun and hose.
to activate the
Maintenance 5:
62.) If both
70.
3A7312D