Graco Electrostatic Air Spray Gun L40T31

Electrical components inside the gun affect performance and safety. Use the following procedures to test the condition of the power supply and gun body, and electrical continuity between components.

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

⚠️⚠️⚡️ Megohmmeter Part No. 241079 (AA – see Fig. 17) is not approved for use in a hazardous location. To reduce the risk of sparking, do not use the megohmmeter to check electrical grounding unless:

• The gun has been removed from the hazardous location;

• Or all spraying devices in the hazardous location are turned off, ventilation fans in the hazardous location 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.

Test Gun Resistance 1. Flush and dry the fluid passage.

2. For Model L40M14, L40T14, L40M15, and L40T15 guns only: Test the barrel continuity to verify that the metal pin in the barrel is properly grounded. Measure resistance between the metal pin (GP) and the air swivel (21). The resistance should be less than 100 ohms. If the resistance is 100 ohms or more, replace the gun body.

3. For all guns: Trigger the gun and measure resistance between the electrode needle tip (3) and the air swivel (21). The resistance should be:

Warning: Always follow the Pressure Relief Procedure whenever you are instructed to relieve the pressure.

Check hoses, tubes, and couplings

Daily Care and Cleaning Checklist

Clean the fluid and air line filters

NOTE: Replace alternator bearings after 2000 hours of operation. Order Part No. 24N706 Bearing Kit. Parts included in the kit are marked with a symbol (♦).

Follow the steps in Prepare the Gun for Service, page 48.

Remove the power supply/alternator assembly and disconnect the alternator. See Power Supply Removal and Replacement, page 54.

Measure resistance between the two outer terminals of the 3-wire connector (PC); it should be 2.0–6.0 ohms.

If outside this range, replace the alternator coil (15a).

Using a flat blade screwdriver, pry the clip (15h) off the housing (15d). Remove the cap (15f), using a thin blade or screwdriver.

If necessary, rotate the fan (15e) so its blades clear the four bearing tabs (T) of the housing (15d).

Push the fan and coil assembly (15a) out the front of the housing (15d).

NOTICE: Do not scratch or damage the magnet (M) or shaft (S). Do not pinch or damage the 3-wire connector (PC) when disassembling and reassembling the bearings.