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-ECTRICAL TROUBLESHOOTI G CHART
PROBLEM
~
CAUSE
Poor wrap-around. *ES ON-OFF valve in OFF position.
'Turbine alternator not operating
Ino audible whine).
Improper distance between gun and workpiece.
Pans poorly grounded.
Operator gets mild shock.
High booth exhaust velocity.
Too high.atomizing air pressure.
*Too low-material resistivity.
'Faulty gun resistance.
'Faulty resistor stud resistance.
'Faulty power supply resistance.
'Faulty needle electrode assembly
'Faulty turbine alternator.
Operator not properly grounded
Gun not properly grounded.
Operator gets mild shock when touching workpiece.
~~~~ ~
Workpiece not properly grounded.
*ES
indicator lights not
"ON" gun is triggered.
SOLUTION
Turn valve to ON.
Check air supply to gun.'Turn ES
ON-OFF valve to on. Check for dirt or moisture in turbine.
Adjust spraying distance to mm (8"-12).
20.30
Clean workpiece hangers. Check for proper ground on conveyor or track.
Reduce, within code limits.
Reduce air pressure.
Check material resistivity with paint meter and probe (refer to instruc- tion manual 307-263).
Check gun resistance. See page 11.
Check resistor stud resistance. See page 11.
Check power supply resistance. See page 11.
Replace needle electrode assembly.
Be sure plug 13cI is in place on back of turbine alternator housing;
Remove and test turbine alternator;
See Service Section: Replace tur- bine alternator if necessary.
Be sure floor is properly grounded,
Wear shoes with non-insulating soles. If gloves are worn, be sure to modify as described in Operation section.
Be sure Graco air supply hose is be- ing used and is properly grounded.
Clean workpiece hangers. Check for proper ground on conveyor or track.
-
The performance of the spray gun is directly affected by the condition of the electrical components contained side the gun. The electrical tests below can be in- used to determine the condition of the power supply (5) and the resistor stud (16) as well as the continuity of the elec- trical path between the components.
L between volts. the
See
WARNING testing to prevent serious bodily injury resulting from explosion or fire caused by sparking.
'Test Gun Resistance
Using a megohmmeter
(DD),
end of gun electrode range, .proceed to the next test.
1 to the air inlet on the gun handle (-), using an applied voltage of
Fig 5. The resistance should be 65-130 megohms. If the resistance is outside the specified
If
( +
1000 the resistance is cor- rect, refer back to the Electrical Troubleshooting Chart for other possible causes of poor performance. -
Test Power Supply Resistance
Remove the power cartridge 13) from gun handle
, described under Power Cartridge Replacement.
(2)
., ,
Remove the turbine alternator (3a) from the power sup- ply (5) as described under Turbine Alternator
Disassembly.
Using a megohmmeter
(DD),
between the center prong (EE) in the power supply
(-1
to the contact spring (+)(5C) on the other end of the power supply, using an applied voltage of 1000 volts.
See
Fig 6. The resistance should be 65-130 megohms. If
the resistance is outside the specified range, the power supply is defective and must be replaced. If the resistance of the power supply next test. is correct, proceed to the
Test Resistor Stud Resistance
Insert a
(GG) conductive rod IFF) into the gun barrel (remov- ed for power supply test) and against the metal contact molded into the front of the barrel. See
Using a megohmmeter (DD), measure the resistance between conductive rod (FF) and gun electrode 112). using an applied voltage of 50-100 volts. The resistance should be 20-30 megohms. If the resistance is correct, refer back to the Electrical Troubleshooting Chart for other possible causes of poor performance or contact the nearest authorized service agency.
If the resistance is outside the specified range, remove electrode 112) as described under Electrode Replace- ment in the Service section and measure the resistance between conductive rod and the resistor in the in- side diameter of resistor stud (16). The resistance electrode (12) is defective and must be replaced. If the resistance is still outside the specified range, resistor stud 116) is defective and must be replaced,
KEY
2
DD
Gun
Gun
Handle
Electrode
KEY
5
Megohmmeter
Prong
Fig 6
5c
KEY
12
18 Gun Barrel
DD
FF
GG
Gun Electrode
Metal Contact
Fig
7
12 f
DD
L 1 8
FF
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