Repair 390 ™ Airless Sprayer 310824D - For portable spray applications of architectural paints and coatings 3300 psi (22.7MPa, 227bar) Maximum Working Pressure IMPORTANT SAFETY INSTRUCTIONS! Read all warnings and instructions. Save these instructions. Contact Graco Customer Service or your local Graco distributor to obtain a manual in your language.
Manual Conventions Contents Manual Conventions . . . . . . . . . . . . . . . . . . . . . . . . 2 Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Component Identification . . . . . . . . . . . . . . . . . . . . 5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Pressure Relief Procedure . . . . . . . . . . . . . . . . . . . 7 General Repair Information . . . . . . . . . . . . . . . . . . 8 Troubleshooting . . . . . . . . . . . . . . . . . . . . . .
Warning Warning The following warnings are for the setup, use, grounding, maintenance and repair of this equipment. The exclamation point symbol alerts you to a general warning and the hazard symbol refers to procedure-specific risks. Refer back to these warnings. Additional, product-specific warnings may be found throughout the body of this manual where applicable. Grounding Instructions This product must be grounded.
Warning WARNING FIRE AND EXPLOSION HAZARD Flammable fumes, such as solvent and paint fumes, in work area can ignite or explode. To help prevent fire and explosion: • Do not spray flammable or combustible materials near an open flame or sources of ignition such as cigarettes, motors, and electrical equipment. • Paint or solvent flowing through the equipment is able to result in static electricity. Static electricity creates a risk of fire or explosion in the presence of paint or solvent fumes.
Warning WARNING EQUIPMENT MISUSE HAZARD Misuse can cause death or serious injury. • Always wear appropriate gloves, eye protection, and a respirator or mask when painting. • Do not operate or spray near children. Keep children away from equipment at all times. • Do not overreach or stand on an unstable support. Keep effective footing and balance at all times. • Stay alert and watch what you are doing. • Do not operate the unit when fatigued or under the influence of drugs or alcohol.
Component Identification Component Identification P S R U B B U K E A A E M N H F H F D J D K ti12008a J T Item 6 T V English A Pressure Control B ON/OFF switch D Power Cord E Fluid Outlet F Prime Valve H Pump J Suction Hose K Drain Hose M Fluid Hose N Gun P Tip R Guard S Trigger Safety Lock T Model/Serial Tag U Filter V Platform 310824D
Installation Installation Grounding and Electric Requirements Do not use the sprayer if the electrical cord has a damaged ground contact. Only use an extension cord with an undamaged ground contact. WARNING Your system must be grounded. Read warnings, page 3. The sprayer cord includes: a grounding wire with an appropriate grounding contact. Recommended extension cords for use with this sprayer: • 110-120V: 3-wire, 12 AWG (2.5 mm2) minimum, 300 ft. (90 m) maximum length. • 240V: 3-wire, 16 AWG (1.
Pressure Relief Procedure Pressure Relief Procedure 3. Turn prime valve down. WARNING Follow this Pressure Relief Procedure whenever you are instructed to relieve pressure, stop spraying, check or service equipment or install or clean spray tip. Read Injection Hazard Warning, page 3. ti5304a 1. Turn OFF power and turn pressure control to lowest pressure setting. 2. Hold gun against side of grounded metal flushing pail. Trigger gun to relieve pressure.
General Repair Information General Repair Information WARNING Read Electric Shock Warning, page 3 and Burn Hazard Warning, page 4. WARNING Flammable materials spilled on hot, bare, motor could cause fire or explosion. To reduce risk of burns, fire or explosion, do not operate sprayer with cover removed. • Keep all screws, nuts, washers, gaskets, and electrical fittings removed during repair procedures. These parts usually are not provided with replacement kits.
Troubleshooting Troubleshooting WARNING Read Electric Shock Warning, page 3, Burn Hazard Warning, page 4 and Pressure Relief Procedure, page 8. Problem What To Check What To Do (If check is OK, go to next check) (When check is not OK, refer to this column) Motor Won’t Operate Basic Fluid Pressure Basic Mechanical 1. Pressure control knob setting. Motor will not run if set at minimum (fully counter-clockwise). Slowly increase pressure setting to see if motor starts. 2.
Troubleshooting Problem Basic Electrical See wiring diagram, page 28 What To Check What To Do (If check is OK, go to next check) (When check is not OK, refer to this column) 1. Electric supply. Meter must read Reset building circuit breaker, replace building fuses. Try another outlet. 100-130 VAC for 110-120 VAC models and 210-255 VAC for 240 VAC models. 2. Extension cord. Check extension Replace extension cord. cord continuity with volt meter. 3. Sprayer power supply cord. Replace power supply cord.
Troubleshooting Problem Low Output What To Check What To Do (If check is OK, go to next check) (When check is not OK, refer to this column) 1. Worn spray tip. Relieve pressure, page 8. Replace tip. Refer to gun instruction manual, 309639. 2. Verify pump does not continue to Service pump. See page 14, Displacement stroke when gun trigger is Pump Replacement. released. 3. Prime valve leaking. Relieve pressure, page 8. Then repair prime valve. See page 24, Manifold Replacement. 4.
Troubleshooting Problem Motor runs and pump strokes Motor runs but pump does not stroke Motor is hot and runs intermittently What To Check What To Do (If check is OK, go to next check) (When check is not OK, refer to this column) 1. Prime Valve Open. Close prime valve. 2. Paint supply. Refill and reprime pump. 3. Intake strainer clogged. Remove and clean, then reinstall. 4. Suction hose leaking air. Tighten nut. Check o-rings on swivel. 5.
Displacement Pump Replacement Displacement Pump Replacement See manual 309250 for pump repair instructions. Removal 4. Cycle pump until pin (32) is in position to be removed. 5. Disconnect power cord from outlet. 6. Using a flat screwdriver, push retaining spring (C) up. Push out pump pin (32). WARNING Read Injection Hazard Warning, page 3, Moving Parts Hazard Warning, page 4 and Pressure Relief Procedure, page 8. 1. Relieve pressure, page 8. C 2. Loosen two screws (30) and rotate cover (44).
Displacement Pump Replacement Installation 5. Screw in pump until threads are flush with top of drive housing opening. WARNING If pump pin works loose, parts could break off due to force of pumping action. Parts could project through air and result in serious injury or property damage. CAUTION If the pump jam nut loosens during operation, the threads of the drive housing will be damaged. 6. Align pump outlet (E) to back. 1. Extend pump piston rod full.
Drive Housing Replacement Drive Housing Replacement Installation WARNING 1. Apply a liberal coat of grease to gears and needle bearing surfaces. Install thrust bearing (4) and gears (2) and (3) in front endbell housing. Read Injection Hazard Warning, page 3 and page 8. Needle bearing surfaces Removal 1. Relieve pressure, page 8. 3 2. Remove pump (9). Displacement Pump Replacement, page 14. Disconnect power cord from outlet. 4 3 4 2 5 7 ti6121a 6 ti5641a 32 30 2 6 2.
Spin Test Spin Test See Wiring Diagram, page 28. WARNING 2. If uneven or no resistance, check for missing brush caps, broken brush springs, brush leads, and worn brushes. Repair as needed, page 19. 3. If still uneven or no resistance, replace motor, page 27. Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. 30 To check armature, motor winding and brush electrical continuity: 1. Relieve pressure, page 8. Disconnect power cord from outlet. 29 2.
Fan Replacement Fan Replacement Removal 3. Remove spring clip (101) on back of motor. WARNING 4. Pull off fan (100). Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. 1. Relieve pressure, page 8. Disconnect power cord from outlet. 2. Remove two screws (30) and shroud (29). Installation 1. Slide new fan (100) in place on back of motor. Be sure blades of fan face motor as shown. 2. Install spring clip (101). 3. Replace shroud (29) and two screws (30).
Motor Brush Replacement Motor Brush Replacement See Wiring Diagram, page 28. Removal Replace brushes worn to less than 1/4 in. (6mm). Brushes wear differently on each side of motor, check both sides. WARNING 2. Push each cap (A) into place over brush. Orient each cap with the 2 projections on either side of the brush lead. You will hear a “snap” when cap is securely in place. 3.
Control Board Replacement Control Board Replacement 6. Pull control board out slightly and then slide it back and off of frame. See Wiring Diagram, page 28. WARNING Make sure power cord is free and NOT wrapped around cord wrap. Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. 7. Remove grommet and wires from strain relief. Removal 1. Relieve pressure, page 8. Disconnect power cord from outlet. A B B 2. Remove two screws (30) and shroud (29). 3.
Control Board Replacement Installation 1. Position grommet and power cord wires through strain relief in control board (33). ti6122a ti6125a 33 3. Carefully slide control board back into place on the side of the motor frame. 2. Reconnect the power cord connectors to the correct terminals indicated on the control board (120V, black and white, 240V, blue and brown) on control board (33). Be sure power cord is routed between the blue high pressure hose to the manifold and the sprayer frame. 4.
Fuse Replacement Fuse Replacement Removal Installation 1. Relieve pressure, page 8. Disconnect power cord from outlet. 1. Replace fuse on control board with spare fuse. 2. Install shroud (29) and two screws (30). 2. Remove two screws (30) and shroud (29). 3. Remove fuse from control board. 4. Remove spare fuse from motor.
Pressure Control Assembly Replacement Pressure Control Assembly Replacement See Wiring Diagram, page 28. 30 WARNING 29 Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. Removal 1. Relieve pressure, page 8. Disconnect power cord from outlet. 2. Remove two screws (30) and shroud (29). ti5766a 3. Disconnect pressure switch connector (A) from control board (33). 4. Remove tape (22) holding wires to manifold. 5. Pull wires back through hole (K) in housing.
Manifold Replacement Manifold Replacement See Wiring Diagram, page 28. WARNING 7. Reconnect fluid hose at pump outlet. 8. Replace barbed fitting (20) and drain line (40). See Drain Line Replacement, page 25. 9. Install shroud (29) and two screws (30). Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. Removal A 1. Relieve pressure, page 8. Disconnect power cord from outlet. 18 33 A 2. Remove drain line (40) and barbed fitting (20) from manifold.
Drain Line Replacement Drain Line Replacement This procedure should be used whenever you replace the manifold and reinstall an existing drain line or install a new drain line using the Drain Line Kit. Removal To remove the drain line (40) from the manifold: 1. Cut drain line (40) from barbed fitting (20). 2. Unscrew barbed fitting (20) from manifold.
Power Cord Replacement Power Cord Replacement Installation See Wiring Diagram, page 28. 1. Follow Control Board Replacement installation instructions, steps 1-4, page 20. WARNING Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. Removal 2. Reconnect, green ground wire (G) to green grounding screw (31) on frame. Be sure terminal on ground faces UP or wires could get caught in shroud. 3. Reattach motor connector (B) and pressure control switch connect (A). 4.
Motor Replacement Motor Replacement 5. Disconnect all leads from board (33) and remove control board. Control Board Replacement, page 20. See Wiring Diagram, page 28. WARNING 6. Remove ground wire (G) from motor endbell. Read Electric Shock Warning, page 3 and Pressure Relief Procedure, page 8. 7. Remove four screws (6) and motor (1) from frame (45). Installation CAUTION Do not drop gear cluster (3) and (2) when removing drive housing (5).
Wiring Diagram Wiring Diagram 120V Model from Motor Red (+) 2 x Yellow Black (-) Replaceable Fuse Pressure Control Assembly ON/OFF Switch ti5643a Black Power Plug Capacitor White Green 240V Model Capacitor Pressure Control Assembly from Motor Red (+) 2 x Yellow Black (-) Replaceable Fuse ON/OFF Switch ti5857a Blue Brown Power Plug Green 28 310824D
Technical Data Technical Data Power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100/120V AC, 50/60 hz, 11A, 1 phase 230V AC, 50/60 hz, 7.5A, 1 phase Generator required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3000 w minimum Maximum working pressure . . . . . . . . . . . . . . . . . . . . . . . 3300 psi (22.7 MPa, 227 bar) Cycles per gallon (liter) . . . . . . . . . . . . . . . . . . . . . . . . . . . 680 (180) Maximum delivery gpm (lpm) . . . . . . . . . . . .
Graco Standard Warranty Graco warrants all equipment referenced in this document which is manufactured by Graco and bearing its name to be free from defects in material and workmanship on the date of sale to the original purchaser for use. With the exception of any special, extended, or limited warranty published by Graco, Graco will, for a period of twelve months from the date of sale, repair or replace any part of the equipment determined by Graco to be defective.
