Air Motor Troubleshooting; Junction Box Panel Troubleshooting - Graco Uni-Drum Instructions Manual

Troubleshooting

Air Motor Troubleshooting

For additional information about the air motor, refer to Related Manuals on page 3 to find the applicable instruction
manual.
Problem
Air motor will not shift directions,
stalled in DOWN position
Air motor will not shift directions,
stalled in UP position
Air motor stalled halfway between
the top and bottom
Air continually exhausting around air
motor shaft.
Air continually exhausting around
the air valve/slide valve
Air continually exhausting from
muffler while the motor is idle
Oil leaking from exhaust port
Frost build-up on muffler

Junction Box Panel Troubleshooting

Problem
Power from PLC control panel is
ON, but no indicator lights are lit at
Junction Box Panel.
54
Cause
Main air valve spool is dirty or
damaged
Air motor shaft seal is damaged
Air valve/slide valve gasket is
damaged
Internal seal damage
Too much lubricant mixed in with the
air supply
Air motor operating at high pressure,
or high cycle rate
Cause
The knife switch disconnect contacts
(KS100 and KS102) are open.
One or more fuses blown.
Voltage limit to circuits in Junction
Box Panel was exceeded.
Solution
Clean/rebuild main air valve.
Replace air motor shaft seal.
Replace the valve gasket.
Rebuild air motor.
Reduce lubricant supply.
Reduce pressure, cycle rate, or duty
cycle of the air motor.
Solution
Check the PLC power connections
at customer's site.
Replace the blown fuse(s). Check
FU136 and FU143 located inside
the knife switch disconnect blocks.
Check the surge suppressors
SUP136 and SUP144. Replace if
required. Reset power to unit.
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