Introduction

Introduction

How the Electrostatic Air Spray Gun Works

The air hose supplies air to the spray gun. Part of the air operates the turbine and the rest of the air atomizes the fluid being sprayed. The turbine generates power, which is converted by the power cartridge to supply high volt- age current to the gun’s electrode.

The fluid source supplies fluid to the hose and gun. The gun must be connected to a voltage isolation system to maintain voltage at the gun. In an isolation system, the entire fluid supply is electrostatically charged. The charged fluid is attracted to the grounded workpiece, wrapping around and evenly coating all surfaces.

Spraying Waterborne Fluids Electrostatically

This electrostatic air spray gun is designed to spray only waterborne fluids with a flash point above 140°F (60°C) and a maximum organic solvent concentration of 20%, by weight, per ASTM Standard D93. Also, the fluid must not sustain burning when tested per ASTM Standard D4206 Sustained Burn Test.

When connected to a voltage isolation system, all of the fluid in the spray gun, fluid hose, and isolated fluid sup- ply is charged to high voltage, which means that the sys- tem has more electrical energy than a solvent-based system. Therefore, only non-flammable fluids (as 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 hazards. When the spray gun charges the isolated fluid to high voltage, it is similar to charging a capacitor or a 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 depends on the system design. Follow the Fluid Voltage Discharge and Grounding Procedure on page 20 before approaching the front of the gun.

CAUTION

The Graco warranty is void if the spray gun is con- nected to a non-Graco voltage isolation system or if the gun is operated above 60 kV.

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HP GRACO OR PRO TI1681A manual Introduction, How the Electrostatic Air Spray Gun Works