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INSTRUCTIONS–PARTS LIST 308–548
Rev. D
This manual contains important
Supercedes Rev. C
warnings and information.
READ AND RETAIN FOR REFERENCE
ELECTRIC, 120 VAC
390sts Airless Paint Sprayer
2750 psi (195 bar) Maximum Working Pressure
Model 231–353, Series A
Complete sprayer with hoses, gun, RAC IV DripLess
Tip Guard and SwitchTip
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
COPYRIGHT 1994, GRACO INC.
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Table of Contents Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ON/OFF Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Major Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Drive Housing, Connecting Rod, Crankshaft . . . . . . 28 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Pressure Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Operation .
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WARNING WARNING INJECTION HAZARD Spray from the gun, leaks or ruptured components can inject fluid into your body and cause ex- tremely serious injury, including the need for amputation. Fluid splashed in the eyes or on the skin can also cause serious injury. Fluid injected into the skin is a serious injury. The injury may look like just a cut, but it is a serious injury. Get immediate medical attention. Do not point the gun at anyone or at any part of the body. Do not put your hand or fin
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WARNING WARNING EQUIPMENT MISUSE HAZARD Equipment misuse can cause the equipment to rupture or malfunction and result in serious injury. INSTRUCTIONS This equipment is for professional use only. Read all instruction manuals, tags, and labels before operating the equipment. Use the equipment only for its intended purpose. If you are not sure, call Graco Technical Assis- tance at 1–800–543–0339. Do not alter or modify this equipment. Check equipment daily. Repair or replace worn or damag
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Major Components N B C A H K E G D M L F J Fig. 1 A Motor DC motor, 120 Vac, 15A, 1 phase B Drive Assembly Transfers power from DC motor to the displacement pump C Pressure Adjusting Knob Controls fluid outlet pressure D ON/OFF Switch Power switch that controls 120 Vac power to sprayer E Fluid Outlet Hose and spray gun is connected here F Displacement Pump Pressurizes fluid to be sprayed through spray gun G 50 ft (15 m) Main Hose 1/4 in. ID, grounded, nylon hose with spring guards o
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Setup 2. Fill the wet–cup (102). Pry off the wet-cup seal. WARNING Fill the cup 1/3 full with Graco Throat Seal Liquid (TSL), supplied. Install the wet-cup seal. If you supply your own hoses and spray gun, be sure the hoses are electrically conductive, that the 3. Plug in the sprayer. Be sure the ON/OFF switch gun has a tip guard, and that each part is rated for (52) is OFF. Plug the cord into a grounded outlet at at least 2750 psi (195 bar) Working Pressure. This least 20 feet away from the spr
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Operation How to Use the Gun Trigger Safety Open or drain, position Closed, or spray position WARNING INJECTION HAZARD If the gun still sprays when the gun trig- ger safety is locked, repair the gun. See manual 308–645, supplied. 1. To engage the gun trigger safety, turn the latch counterclockwise toward the handle until the detent of the latch locks on and the pin is at a right angle with the gun body. See Fig. 3. 04646 Fig. 4 2. To disengage the gun trigger safety, turn the latch clock
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Operation How to use the RAC IV tip guard. WARNING INJECTION HAZARD To reduce the risk of serious injury, whenever you are instructed to relieve pressure, follow the Pressure Relief Procedure on page 9. The tip guard alerts you to the risk and helps prevent placing any part of the body close to the spray tip. The Tip handle shown in spraying position. tip guard also adjusts the vertical or horizontal spray pattern. See Fig. 8. The tip guard holds a reversing Turn handle 180, spray tip.
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Startup NOTE: If this is a first-time startup, flush the sprayer. WARNING See page 13. INJECTION HAZARD NOTE: Refer to Fig. 9 and the other figures referenced The system pressure must be manually in the text as you start the sprayer. relieved to prevent the system from starting or spraying accidentally. Fluid 1. Open the pressure drain valve (42). See Fig. 7. under high pressure can be injected through the skin and cause serious injury. To reduce the risk of 2. Don’t install the spray tip until
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Startup b. If more coverage is needed, use a larger tip WARNING rather than increasing the pressure. FIRE AND EXPLOSION HAZARD To reduce the risk of static sparking and c. Adjust the direction of the spray pattern. See splashing when priming or flushing the Fig. 8. Engage the gun safety latch. Loosen system, hold a metal part of the gun the retaining nut (A). Position the tip guard for firmly to the side of a grounded metal pail before a horizontal or vertical pattern. Hold the tip triggering th
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Startup 32 1/4 npsm(m) fluid outlet 33 Do not install any shutoff device here Rotate clockwise to increase pressure 64 Shown in closed or spray position Fill 1/3 full with TSL 28 74 52 102 67 Fig. 9
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Shutdown and Care WARNING WARNING INJECTION HAZARD INJECTION HAZARD See the warning section INJECTION To reduce the risk of serious injury, HAZARD on page 3 for information on whenever you are instructed to relieve the hazard of using damaged hoses. pressure, follow the Pressure Relief Procedure on page 9. Shutdown and Care Turn packing nut clockwise to tighten 1. Check the packing nut/wet-cup daily (102). Re- lieve pressure first. Keep the wet-cup 1/3 full of TSL at all times to help prevent
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Flushing 3. Pour one-half gallon (2 liters) of compatible solvent When to Flush into a grounded metal flushing pail. Put the suction 1. Before using a new sprayer: flush out the oil hose in the pail. which was left in to protect pump parts. 4. Open the pressure drain valve. See Fig. 4, page Before using water-base paint: flush with min- 7. eral spirits followed by soapy water, and then a clean water flush. 5. To save the paint still in the pump and hose, follow Step 6, except put the drain tube
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Troubleshooting WARNING INJECTION HAZARD To reduce the risk of serious injury, whenever you are instructed to relieve pressure, follow the Pressure Relief Procedure on page 9. Basic Problem Solving Check everything in the troubleshooting table before disassembling the sprayer. TYPE OF PROBLEM WHAT TO CHECK WHAT TO DO If check is OK, go to next check When check is not OK, refer to this column Fluid pressure 1. Check pressure control knob setting. The pump 1. Slowly increase pressure setting to se
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Basic Problem Solving TYPE OF PROBLEM WHAT TO CHECK WHAT TO DO If check is OK, go to next check When check is not OK, refer to this column Electrical (continued) 5. Check motor armature commutator for burn 5. Remove motor and have motor shop spots, gouges and extreme roughness. Re- resurface commutator if possible. See move motor cover and brush inspection plates page 26. to check. See page 20. 6. Check motor armature for shorts using arma- 6. Replace motor. See page 26. ture tester (growler) or
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Intermediate Problem Solving TYPE OF PROBLEM WHAT TO CHECK WHAT TO DO If check is OK, go to next check When check is not OK, refer to this column Low output (continued) 3. Release gun trigger. Observe resting position of 3. If pump consistently comes to rest with pump rod (107). rod (107) fully extended, the piston pack- ings and/or piston valve may be worn. Service the pump. See page 22. 4. Check electrical supply with volt meter. Meter 4. Reset building circuit breaker; replace should read 105
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Intermediate Problem Solving TYPE OF PROBLEM WHAT TO CHECK WHAT TO DO If check is OK, go to next check When check is not OK, refer to this column 1. Spray tip worn beyond sprayer pressure capa- 1. Replace spray tip. Spray Pattern Variations bility. NOTE: A smaller size tip will provide longer life. 2. Check transducer (29) for wear or damage. 2. Replace transducer. See page 31. 3. Check pressure control (64) for smooth opera- 3. Replace pressure control. See page 30. tion. 4. Check Low output se
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Motor Test WARNING INJECTION HAZARD To reduce the risk of serious injury, whenever you are instructed to relieve pressure, follow the Pressure Relief Procedure on page 9. B For checking armature, motor winding and brush elec- trical continuity. Setup A Remove the drive housing. See page 28. This is to ensure that any resistance you notice in the armature test is due to the motor and not to worn gears in the drive housing. Remove the motor brush inspection covers (A). See Fig. 12. Fig. 12 R
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General Repair Information WARNING WARNING INJECTION HAZARD HOT SURFACE HAZARD During operation, the motor and drive To reduce the risk of serious injury, housing become very hot and could burn whenever you are instructed to relieve your skin if touched. Flammable materi- pressure, follow the Pressure Relief als spilled on the hot, bare motor could cause a fire Procedure on page 9. or explosion Tool List CAUTION These are the tools required to service all parts of the To reduce the risk of a pr
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Motor Brushes NOTE: Replace brushes when worn to about 0.5 in. Motor lead; do not disconnect (12.5 mm). Always check both brushes. Brush Repair Minimum 0.5” (12.5 mm) Kit 236–967, which includes spring clip 112–766, is Included in Brush Repair available for motors manufactured by Pacific Scientific. Kit 236–967 NOTE: Replacement brushes may last only half as C H long as the original ones. To maximize brush life, break G in new brushes by operating the sprayer for at least F one hour
