Graco Inc 3500WB Introduction, Spraying Waterborne Fluids Electrostatically, Refer to , page

Page 6

Introduction

Spraying Waterborne Fluids

Electrostatically

The PRO 3500wb spray gun is a 60 kV electrostatic spray gun that is designed to spray conductive, water- borne, non-flammable fluids. When spraying water- borne fluids electrostatically, the gun must be con- nected to a voltage isolation system, which isolates the fluid supply from ground and allows voltage to be maintained at the tip of the gun.

A safe, well designed isolation system should have the following features:

DAll components of the isolation system that are charged to high voltage must be contained within a fence or enclosure that prohibits personnel from making contact with the high voltage components.

DA means for automatically discharging the system voltage if anyone opens the fence or enclosure.

DA bleed resistor to drain off the system voltage when the spray gun is not in use.

DThe system should not have any severe arcing occurring when the isolation mechanism opens and closes. Severe arcing will shorten the life of the system components.

When connected to a voltage isolation system, all of the fluid in the spray gun, fluid hose, and isolated fluid supply are charged to high voltage, which means that the system has more electrical energy than a solvent- based system. Therefore, only non-flammable fluids (defined on the front cover of this manual) can be sprayed with the system or be used to clean, flush. or purge the system.

Precautions must be taken when using electrostatic waterborne equipment to avoid potential shock haz- ards. When the spray gun charges the isolated fluid to high voltage, it is similar to charging a capacitor or battery. The system will store some of the energy while spraying and retain some of that energy after the spray gun is shut off. It is not safe to touch the front end of the gun until the stored energy is discharged. The amount of time it takes to discharge the energy de- pends on the system design. Follow the Fluid Voltage Discharge and Grounding Procedure, page 16, before approaching the front of the gun.

Do not intentionally ground out the system by arcing the electrode to ground when you are done spraying. Sudden arcs or shocks to the gun and system puts extra stress on the components and will shorten the life of the gun and fluid hose. When hanging up the gun, avoid arcing the gun to a grounded gun hanger. An optional plastic gun holster is available, which can be used to hang up the gun without causing arcs.

Operating the Electrostatics

Refer to Fig. 1, page 7

To operate the electrostatics, air pressure is supplied through a Graco electrically conductive air hose to the gun air inlet (F). When the gun is triggered, air enters the gun and is directed to the inlet of the turbine/alter- nator (T). The air spins the turbine, which then pro- vides electrical power to the power supply. The fluid is charged by the spray gun electrode (B). The charged fluid is attracted to the nearest grounded object, wrap- ping around and evenly coating all surfaces.

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Contents 100 psi 0.7 MPa, 7 bar Maximum Working Pressure INSTRUCTIONS-PARTS LIST308584 Part No. 222700, Series CWarning Symbol Table of ContentsSymbols Caution SymbolELECTRIC SHOCK HAZARD FIRE AND EXPLOSION HAZARD PRESSURIZED EQUIPMENT HAZARDWarnings are continued on the next page EQUIPMENT MISUSE HAZARD TOXIC FLUID HAZARDOperating the Electrostatics IntroductionSpraying Waterborne Fluids Electrostatically Refer to Fig. 1, pageB A C D Conductive Hose Layer DD covers the PTFE tube Graco Waterborne Fluid Hose purchased separatelyD Inner Hose Layer EE is a PTFE tube H2O PRO Voltage Block connection shownVentilate the Spray Booth InstallationInstalling the System Warning SignsT S N K L Consult your isolation system manual for other configurationsPRO 3500wb Gun shown with the Graco H2O PRO Batch System M G F NH R B A E D P CConnect the Air Line Install the Air Line AccessoriesInstall the Fluid LIne Accessories Connect the Exhaust TubeFilter the Fluid Connect the Fluid HoseContinued on the next page Connect the Fluid Hose continued H2O PRO Voltage Blockconnection shown Ground the System FIRE, EXPLOSION, AND ELECTRIC SHOCK HAZARDCheck the Electrical Grounding Fluid Voltage Discharge and Grounding Procedure Pressure Relief ProcedureOperation Operating Checklist Selecting a Fluid Nozzle and Air CapOperating the Spray Gun FIRE AND EXPLOSION HAZARDCOMPONENT RUPTURE HAZARD Atomizing Air Valve Adjustment Fine Adjustments of the Spray GunMaintenance Daily Care and CleaningShutdown Flush the Spray Gun Clean the Air Cap and Fluid NozzleProcedure Equipment neededSpray Gun TroubleshootingVoltage Loss Troubleshooting Waterborne Fluid HoseVoltage Loss Troubleshooting continued TestsSolution Electrical TroubleshootingProblem CauseSpray Pattern Troubleshooting Poor Electrostatic Wrap Troubleshooting Gun Operation TroubleshootingGun Operation Troubleshooting continued Electrical Tests Test Gun ResistanceTest Power Supply Resistance Test Resistor Stud ResistanceAir Cap/Nozzle/Resistor Stud Replacement ServicePrepare the Gun for Service Tools Included with the GunAir Cap/Nozzle/Resistor Stud Replacement continued InstallationElectrode Needle Replacement Fluid Packing Rod Removal and Repair Preventative MaintenanceIf installing the complete fluid rod assembly, go to step 11, page WhereFluid Packing Rod Removal and Repair continued If installing the complete valve, go to step Fan Air Adjustment Valve RepairFluid Adjustment Assembly Repair DETAILFluid Adjustment Assembly Repair continued Air Trigger Valve Repair Apply a very light coat of lubricant to the o-rings 41 Atomizing Air Valve Repair ES ON-OFF Valve Repair MOVING PARTS HAZARD05363B Barrel Removal Power Supply Replacement  Apply a very light coat of lubricant to the o-rings 37a Do not expose the gasket 18a to solvents Turbine Alternator Replacement Barrel Installation05158B Graco Waterborne Fluid Hose Repair Measurements, inches mmPRO 3500SC Gun Disassembly NOTE Keep all the following parts for reassemblyPRO 3500sc Gun Conversion Installing the Fluid Needle Assembly 10. Tighten the nut 78* onto the ferrule housing Spray Gun Parts See Detail AY Replacement Warning signs are available at no cost EQUIPMENT MISUSE HAZARDPart No. 222700, Series C Model PRO 3500wb Spray Gun DescriptionWaterborne Fluid Hose Assembly AccessoriesUse Only Genuine Graco Parts and Accessories 100 psi 0.7 MPa, 7 bar Maximum Working PressureSnap Ring Pliers For use in the Fluid Voltage Discharge and Ground- ing ProcedureManual Change Summary Gun High Voltage Probe & MeterPage Technical Data CategoryData WARRANTY The Graco Warranty and DisclaimersGraco Phone Number EQUIPMENT NOT COVERED BY GRACO WARRANTY
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