Troubleshooting - Graco PR70 Series Operation And Maintenance Manual

Troubleshooting

Troubleshooting
Before starting any troubleshooting procedures:
1. Relieve pressure (refer to Pressure Relief
Procedure Section).
2. Disconnect AC power to the machine.
PROBLEM
HMI Display Completely Dark
No or incorrect amount of
material dispensed from either
side
Piston stalled (E21 Error)
Significant material leaking
from pump rear seal
Material dispensed not correct
weight
Machine dispensing off ratio
Pumps drawing material back
from valve hose
312393C
CAUSE
No Power
Fuse Blown
Loose connection
Bad HMI
Ball Valve Closed
Tank empty
Tank Cloged
Air in material
Check valve malfunction
Piston worn or broken
Input Air Reduced or
removed
Mixer blocked
ODV adjustment too late
Blocked Check valve
Air Cylinder Failure
Pump Shaft worn
Specific gravity of 1 or more
of the 2 materials has
changed since calibration.
Machine Air pressure has
changed since calibration.
Not enough material in 1 or
more tanks
Mixer has slight obstruction
Check valve malfunction
Piston worn or broken
One tank is empty
Tank Ball valve Closed
Machine out of phase
Check valve malfunction
Piston worn or broken
Check valve stuck open
3. Allow the machine to cool, if the machine has a heat
control option.
Try the recommended solutions in the order given for
the each problem to avoid unnecessary repairs. Also
verify all circuit breakers, switches, and controls are
properly set and wiring is correct before assuming there
is a problem.
Verify rear AC Power switch is ON.
Replace Machine fuses (Refer to "Miscellaneous
Mechanical Assemblies" Section).
Tighten 5 pin cable on HMI.
Replace HMI
Open Tank Ball Valve (if installed).
Fill tank with material
Verify no obstruction in the tank
Prime the machine until the air is removed.
Remove, clean or replace check valve.
Remove and replace piston if worn.
Re-connect input air line to machine. Increase
air pressure regulator adjustment.
Replace static mixer. Incorporate or decrease
purge time amount to prevent mixer blockage.
Re-adjust the ODV setting to occur sooner (C3
screen section).
Remove check valve, clean and replace.
Remove air cylinder and re-install cylinder kit
items if necessary.
Remove pump shaft assembly, and re-install rear
pump re-built kit.
Mix materials in tanks, dispense another shot,
then re-weigh. Re-calibrate if necessary (C4
section).
Re-adjust air pressure regulator to value used
when machine was calibrated, or re-calibrate (C4
section). Turn ON or decrease
Check tank levels, and fill and prime if
necessary.
Replace static mixer. Re-prime machine.
Remove check valve(s), clean or replace if
necessary.
Remove and replace piston(s) if necessary.
Check tank levels. Add material if necessary.
Open tank ball valve. Re-prime machine.
Re-phase machine (C2 section).
Remove check valve(s), clean or replace if
necessary.
Remove and replace piston(s) if necessary.
Remove check valve(s), clean or replace if
necessary.
SOLUTION
% level.
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