Introduction
6
309457G
Introduction
How the Electrostatic Air Spray
Gun Works
The automatic electrostatic air spray gun operates very
similar to a traditional air spray gun. The atomization
and fan air are emitted from the air cap. The atomization
air breaks up the fluid stream and controls the droplet
size. The fan air controls the shape and width of the
spray pattern. The fan and atomization air can be
adjusted independently.
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 21 before
approaching the front of the gun.
A safe, well designed voltage isolation system should
have the following features:
•
All components of the isolation system that are
charged to high voltage must be contained within an
enclosure that prohibits persons from making con-
tact with the high voltage components before the
system voltage is discharged.
•
The voltage isolation system must be interlocked
with the spray area entrance to automatically dis-
charge the voltage and ground the fluid whenever
someone opens the enclosure or enters the spray
area.
•
A bleed resistor to drain off the system voltage when
the spray gun is not in use.
•
The system should not have any severe arcing
occurring when the isolation mechanism opens and
closes. Severe arcing will shorten the life of the sys-
tem components.
Gun Features and Options
•
The gun is designed for use with a reciprocator, and
can be mounted directly on a 1/2 in. (13 mm) rod.
With additional brackets, the gun can be mounted
for robotic applications.
•
Gun functions are activated from a separate control-
ler that sends the appropriate signal to the actuating
solenoids.
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.
Summary of Contents for PRO Auto Xs
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