Graco 333013B, Instructions - Parts Manual

Page: 29 / 62

Electrical Tests
333013B 29
Electrical Tests
Use the following procedures to test the condition of the
power supply and gun body, and electrical continuity
between components. See
Power Supply Removal
and Replacement , page 43.
Use megohmmeter Part No. 241079 (AA) and an
applied voltage of 500 V. Connect the leads as shown.
Test Gun Resistance
1. Flush and dry the fluid passage.
2. Measure the resistance between the electrode (25a)
and the turbine air fitting. The resistance should be
104–150 megohms. If outside this range, go to
Test
Power Supply Resistance , page 29. If in range,
see Voltage Loss Troubleshooting , page 31 for
other possible causes of poor performance, or con-
tact your Graco distributor.
Test Power Supply Resistance
1. Remove the power supply (7), page 43.
2. Remove the turbine (8) from the power supply, page
44.
3. Measure resistance from the power supply's ground
strips (EE) to the spring (7a). See F
IGURE
21.
4. The resistance should be 90-115 megohms. If out-
side this range, replace the power supply. If in
range, proceed to the next test.
5. If you still have problems, refer to Electrical Trou-
bleshooting , page 37 for other possible causes of
poor performance, or contact your Graco distributor.
6. Be sure the spring (7a) is in place before reinstalling
the power supply.
Test Barrel Resistance
1. Insert a conductive rod (B) into the gun barrel
(removed for the power supply test) and against the
metal contact (C) in the front of the barrel.
2. Measure the resistance between the conductive rod
(B) and the conductive ring (33). See F
IGURE
22.
The resistance should be 10-30 megohms. If the
resistance is incorrect, make sure the metal contact
(C) in the barrel and the conductive ring (33) are
clean and undamaged.
Megohmmeter Part No. 241079 (AA-see F
IGURE
20)
is not approved for use in a hazardous area. To
reduce the risk of sparking, do not use the
megohmmeter to check electrical grounding unless:
• The gun has been removed from the hazardous
area;
• Or all spraying devices in the hazardous area are
turned off, ventilation fans in the hazardous area
are operating, and there are no flammable vapors
in the area (such as open solvent containers or
fumes from spraying).
Failure to follow this warning could cause fire,
explosion, and electric shock and result in serious
injury and property damage.
F
IG
. 20 . Test Gun Resistance
AA
25a
TA
TA
F
IG
. 21 . Test Power Supply Resistance
7a
EE