Troubleshooting 3Z8 038 Rev B INSTRUCTIONS WARNING INJECTION HAZARD This form is only a quick reference for troubleshooting Graco sprayers. To reduce the risk of serious injury, including fluid injection, while operating, checking, or repairing the sprayer, follow the warnings and instructions in the appropriate complete instruction manual. General Applies to all Airless Paint Sprayers Problem Cause Solution Poor spray pattern, tails Spray tip is worn or too big. Replace the tip. Not enough pressure Paint is too thick. Thin the paint. Stall pressure is out of calibration. Recalibrate the stall pressure. Low fluid delivery Pressure setting is too low. Increase the pressure setting. Excessive surges at the gun Hose is too long, or the diameter is too large. Tip is plugged. Outlet filter is clogged. Pump parts are worn. For longer hoses, pressure drop is much less with 3/8 in. hose than with 1/4 in. hose. One 50 ft. (15 m) length of 3/8 in. hose can increase spraying pressure by as much as 300 psi (21 bar). Unplug the tip. Flush and clean the outlet filter. Check rod, cylinder, piston valve, and intake valve for wear. Repack the pump; use available kit. Paint runs or sags Tip is worn or too big. Replace the tip. Static sparking from gun Sprayer and/or work are not properly grounded. Hose is damaged or is not a static-free airless hose. Ensure that the sprayer and work are grounded. Replace the hose. Spray gun will not shut off Needle and/or diffuser is worn. Repair the gun; use available kit. Paint is built up between needle and diffuser. Clean the gun. Spray gun will not spray Paint supply is empty. Replenish the paint supply. Displacement pump output low Spray tip is clogged. Filter is clogged (gun or sprayer). Pump inlet screen is plugged. Piston ball check is not seating. Intake ball is not seating. Packings are worn or damaged. Clean the tip. Clean the filter. Clean the screen. Replace the piston ball. Replace the intake ball. Repack the pump; use available kit. General Troubleshooting continued
General Applies to all Airless Paint Sprayers (continued) Problem Cause Solution Paint leaks into wet-cup Throat packings are worn or damaged. Repack the pump; use available kit. Throat packing nut is loose. Piston rod is damaged. Tighten the throat packing nut just enough to stop the leakage. Replace the piston rod. Pump is hard to prime Air is trapped in the pump. Open the drain valve. When fluid appears, close it. There is an air leak in the connection between the pump and suction tube or siphon tube. Intake valve or piston valve is leaking or stuck. Packings are worn. Paint is too thick. Inlet screen is plugged Tighten the connection. Clean or replace the valve. Repack the pump; use available kit. Thin the paint. Clean or replace the screen. General Applies to Specified Types of Sprayers Problem Applies To: Cause Solution Sprayer will not start Electric sprayers Sprayer is not plugged in. Plug in the sprayer. Motor does not run, or it stops while spraying Electric sprayers ON/OFF switch is turned off. Turn on the switch. Sprayer was left pressurized. Trigger the gun. EM, GM, Ultra sprayers Pressure setting is too low. Motor is overheated. Circuit breaker is tripped, or power supply fuse is blown. Motor is damaged. Spray tip or filter is plugged. Bourdon tube is damaged from freezing or overpressurization. Increase the pressure. Allow the motor to cool. Reset the circuit breaker, or replace the power supply fuse. Replace the motor. Clean the tip or filter. Replace the control box. EM390, EM490 Extension cord is too long. Use a maximum 50 ft (15 m), 12 ga., grounded extension cord. AC motor labors when starting EM390, EM490 Capacitor has failed. Replace the capacitor. Circuit board has failed. Replace the circuit board. Gasoline engine will not start All gas-powered sprayers Gasoline tank is empty. Spark plug cable is disconnected. Refill the gasoline tank. Reconnect the cable. GM3500, GM5000 Oil level is low. Engine switch is not on. Add oil. Turn on the switch. General Troubleshooting continued
General Applies to Specified Types of Sprayers (continued) Problem Applies To: Cause Solution Gasoline engine will not start (continued) GH733 Battery is dead. Recharge or replace the battery. Excessive leakage around hydraulic motor piston rod wiper All hydraulicpowered sprayers Piston rod seal is worn or damaged. Replace the seal. Motor/engine runs, but pump does not work All sprayers Pressure setting is too low. Increase the pressure. Tip or filter is plugged. Clean the tip or filter. EH333, EH433 GH533, GH733 GM3500, GM5000 Outlet filter is plugged. Pump is stuck, because material has dried in it. Hydraulic fluid is low. Hydraulic pump is worn or damaged. Hydraulic motor is worn or damaged. Hydraulic motor is stalled. Pressure control switch is turned off. Clutch field is not energized. Clutch is sticking, worn, or damaged. Flush and clean the filter. Repack the pump; use available kit. Add hydraulic fluid. Replace the pump. Replace the motor. For EH333 and EH433, reset the hydraulic motor as follows: 1. Shut off the engine/electric motor to relieve pressure in the hydraulic motor. 2. Remove the nut from the top of the hydraulic motor. The spool is revealed. 3. Use a screwdriver to push down on the top of the spool about 1/2 in. until it is about 1 in. below flush with the top of the hydraulic motor. 4. Replace the nut on the top of the hydraulic motor. For GH533 and GH733, reset the hydraulic motor as follows: 1. Shut off the engine/electric motor to relieve pressure in the hydraulic motor. 2. Press the reset button on the top of the hydraulic motor. Turn on the switch. Check for loose connections; replace the clutch field. Replace the clutch.
Ultra and Ultra Plus+ Electrical Troubleshooting NOTE: Check the GENERAL troubleshooting on the previous pages also. Problem Cause Solution Electrical problems Sprayer circuit breaker has popped up. Press the button to reset the circuit breaker. If the circuit breaker continues to open, see Electrical Short on page 6. Diagnosing circuit board indicator lamps. The normal condition is red lamp on, clear lamp on when board is telling pump to run. Condition A Both lamps on, pump does not operate, and motor is not running Motor brush leads or terminals are loose or damaged. Brushes are worn. Brushes should be at least 1/2 in. long. Leads from bridge to motor are not securely fastened and properly mated. G1 and G2 connections between circuit board and bridge or terminals are damaged or loose. Motor brush lead connections and terminals are loose. Brushes are worn. Brushes should be at least 1/2 in. long. Motor brush springs are broken or misaligned. Rolled portion of spring must rest squarely on top of brush. Motor brushes are binding in brush holders. Motor armature commutator has burn spots, gouges and extreme roughness. Motor armature has shorts. Bridge is not functioning properly. Tighten the terminal screws. Replace the terminals and brushes. Replace loose terminals; crimp to leads. Be sure male terminal blades are straight and firmly connected to their mating parts. Clean the circuit board male terminals. Replace loose or damaged terminals. Securely reconnect the leads. Tighten the terminal screws. Replace the brushes if the leads are damaged. Replace the brushes. NOTE: The brushes do not wear at the same rate on both sides of the motor. Check both brushes. Replace the spring if it is broken. Realign the spring with the brush. Clean the brush holders. Remove the carbon with a small cleaning brush. Align the brush leads with the slots in the brush holder to assure free vertical brush movement. Remove the motor cover and brush inspection plates to check. Remove the motor and have the motor shop resurface the commutator, if possible. Check the motor armature for shorts using an armature tester (growler), or perform the spin test. Replace the motor. Check the bridge by substituting it with a good bridge or by performing the bridge test. Replace the bridge. CAUTION Do not perform this check until the motor armature is determined to be good. A bad motor armature will immediately burn out a good bridge. Ultra and Ultra Plus+ Electrical Troubleshooting continued
Ultra and Ultra Plus+ Electrical Troubleshooting (continued) Problem Cause Solution Condition B Both lamps off Condition C Red lamps on, clear lamp off Unplug sprayer Low output Circuit breaker button has popped up. Power supply cord is damaged. ON/OFF switch is not working. Circuit breaker is not working. Motor thermal cutout switch is not working. Microswitch is not working. Microswitch is faulty. Circuit board is not functioning properly. Circuit board is not functioning properly. Bourdon tube flag and detector are not properly positioned. G1 and G2 leads from bridge to circuit board are defective. Circuit board is not functioning properly. Motor brush leads and terminals are loose. Motor brushes are worn. Motor brushes should be at least 1/2 in. long. Pressure control board is not functioning properly. Motor armature has shorts. Press the button to reset the circuit breaker. If the circuit breaker continues to open, see Electrical Short on page 6. Replace the cord. Replace the switch. Replace the circuit breaker. Allow the motor to cool, correct the cause of overheating, and replace the motor. Clean the microswitch terminals. Replace loose or damaged terminals. Securely reconnect the leads. Visually inspect the microswitch button. The adjustment stud should not press the button when the fluid pressure is zero. Press the button with a small screwdriver. An audible click indicates that the microswitch is in its normal position. If the microswitch is faulty, return the sprayer for repair. Check the circuit board by substituting it with a good board. Replace the circuit board. Replace the circuit board. Perform the pressure control adjustment procedure. If that does not correct the problem, replace the pressure control. Clean the circuit board male terminals. Replace loose or defective lead terminals. Securely reconnect the lead terminals to the board. Check the circuit board by substituting it with a new board. Replace the circuit board. Tighten the terminal screws. Replace the brushes if the leads are damaged. Replace the brushes. Check the pressure control board by substituting it with a good pressure control board. Replace, if necessary. Check the motor armature for shorts, using an armature tester (growler), or perform the spin test. Replace the motor.
Ultra and Ultra Plus+ Electrical Troubleshooting (continued) Motor Does Not Operate Type of Problem Basic electrical problems What to Check If check is OK, go to next check. 1. Check the pressure control safety circuit. NOTE: This is possible on Ultra Plus+ sprayers only. 2. Check the electrical supply with a volt meter. The meter should read 105 to 125 VAC. 3. Check the extension cord for damage, and check the extension cord continuity with a volt meter. 4. Check the sprayer power supply cord for damage, such as broken insulation or wires. 5. Check the motor brush leads, terminals, and brush length. Brushes should be at least 1/2 in. long. What to Do When check is not OK refer to this column. 1. Turn the pressure control ON/OFF switch to OFF to RESET. If the pressure control safety continues to trip, see Electrical Short on page 6. 2. Reset the building circuit breaker or replace the building fuse. Try another outlet. 3. Replace the extension cord. 4. Replace the power supply cord. 5. Tighten the terminal screws. Replace the brushes. Electrical Short Type of Problem Building circuit breaker opens as soon as sprayer switch is turned on. CAUTION Any short in any part of the motor power circuit will cause the control circuit to inhibit sprayer operation. Correctly diagnose and repair all shorts before checking and replacing control board. Building circuit breaker opens as soon as sprayer is plugged into outlet, and sprayer is NOT turned on. Sprayer quits after 5 to 10 minutes of operation. What to Check If check is OK, go to next check. 1. Check all electrical wiring for damaged insulation and all terminals for loose fit or damage. Also, check the wires between the pressure control and the motor that are encased in the conduit. 2. Check for missing inspection plate gasket, bent terminal forks, or other metal-to-metal contact points that could cause a short. 3. Check the motor armature for shorts. Use an armature tester (growler), or perform the spin test. Inspect windings for burns. 4. Check the pressure control board by substituting it with a good control board. 1. Check the basic electrical problems under Motor Does Not Operate above. 2. Check the ON/OFF switch. Be sure the sprayer is unplugged! Disconnect the wires from the switch. Check the switch with an ohmmeter. The reading should be infinity with the ON/OFF switch OFF, and zero with the switch ON. 3. Check for damaged or pinched wires in the pressure control. 1. Check the basic electrical problems under Motor Does Not Operate above. 2. Check the electrical supply with a volt meter. The meter should read 105 to 125 VAC. 3. Check the tightness of pump packing nut. Overtightening tightens the packings on the rod, restricts pump action, and damages the packings. What to Do When check is not OK refer to this column. 1. Repair or replace any damaged wiring or terminals. Securely reconnect all wires. 2. Correct any faulty conditions. 3. Replace the motor. 4. Replace the pressure control board with a new board. 1. Perform any necessary procedures. 2. Replace the ON/OFF switch. 3. Replace any damaged parts. 1. Perform any necessary procedures. 2. If the voltage is too high, do not operate the sprayer until it is corrected. 3. Loosen the packing nut. Check for leaking around the throat. Replace the pump packings if necessary.
Notes
Notes GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440 1441 COPYRIGHT 1995, GRACO INC. PRINTED IN U.S.A. 3Z8 038 August 1995 TO PLACE AN ORDER, call 1 800 367 4023 Toll Free FOR TECHNICAL ASSISTANCE, call 1 800 543 0339 Toll Free