Graco Inc 247937, 247936, 312900C Electrical Tests, Test Gun Resistance, Test Total Gun Resistance

Electrical Tests

Electrical components inside the gun affect performance and safety. The following procedures test the condition of the power supply (18), barrel (16) and charging probe (31), and electrical continuity between components.

Use megohmmeter Part No. 241079 (AA) and an applied voltage of 500 V. Connect the leads as shown.

Electrical Tests

Test Gun Resistance

Measure resistance between the air swivel (35) and the charging probe socket (CC) (see FIG. 9); it should be

70-95 megohms. If outside this range, check the power supply and barrel resistance. If in range, test the charg- ing probe resistance.

Fire, Explosion, and Electric Shock Hazard

Megohmmeter Part No. 241079 (AA-see FIG. 8. through FIG. 12.) is not approved for use in a hazard- ous areas. 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, explo- sion, and electric shock and result in serious injury and property damage.

Test Total Gun Resistance

Measure resistance between the charging probe tip

(BB)and the air swivel (35) (see FIG. 8.); it should be 90-130 megohms. If outside this range, go to the next test. If in range, refer to Gun Repair on page 27 for other possible causes of poor performance.

AA

BB

35

ti1468ax

Fig. 8. Test Total Gun Resistance

	AA
35	CC
	ti13731

FIG. 9. Test Gun Resistance

Test Charging Probe Resistance

Measure resistance between the metal spring in the charging probe (DD) and the charging probe tip (BB) (see FIG. 9); it should be 15-30 megohms. If outside this range, replace the charging probe. If in range, inspect the spring and barrel socket for possible causes of poor continuity. Reassemble the charging probe and retest the gun resistance.

AA

BB

DD

ti13732

FIG. 10. Test Charging Probe Resistance

312900C 23