User's Manual

Overview
313227C 5
Overview
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.
Operating the Spray Function
Applying a minimum of 50 psi (0.35 MPa, 3.5 bar) air
pressure to the gun manifold’s cylinder air fitting (CYL)
will retract the gun piston, which opens the air valves
and a short time later opens the fluid needle. This pro-
vides the proper air lead and lag when triggering the
gun. A spring returns the piston when the cylinder air is
shut off.
Operating the Electrostatics
To operate the electrostatics, apply air pressure to the
gun manifold’s turbine air fitting (TA) through a Graco
grounded air hose. The air enters the manifold and is
directed to the inlet of the power supply turbine. The air
spins the turbine, which then provides electrical power
to the internal high voltage power supply and external
charging probe. Atomized fluid particles become
charged as they pass by the external probe, and are
attracted to the grounded workpiece, evenly coating all
surfaces. The external charging allows the fluid supply
to remain grounded at all times, eliminating the need for
an isolation system.
The turbine air is exhausted into the shroud and out the
back of the manifold through the exhaust fitting (EXH).
The exhaust air helps keep contaminants out and helps
keep the gun clean.
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.
• The gun’s quick-disconnect design enables its
removal without disconnecting the fluid and air lines
to the gun.
• Gun functions are activated from a separate control-
ler that sends the appropriate signal to the actuating
solenoids.
• The optional fiber optic readout system can be
installed to monitor the gun’s spraying voltage. A
fiber optic cable connected to the gun manifold car-
ries the signal from the gun to a remote display
module. Part No. 224117 Display Module displays
the gun’s spraying voltage and current. Bat-
tery-operated Display Module 189762 displays the
gun’s spraying voltage only.
Changing the kV Setting
For this external charge gun it is recommended that the
gun be left at full voltage, but if needed the voltage can
be reduced.
The gun’s full voltage setting is 60 kV. Three lower volt-
age settings are possible by actuating the KV1 and KV2
switches. Supply 50 psi (0.35 MPa, 3.5 bar) air pressure
to the KV1 and KV2 ports. Turn the air on or off as
shown in Table 1 to set the desired voltage.
NOTE: The solenoid valves used to activate the KV1
and KV2 switches must bleed the air out of the lines for
the switches to draw back to the higher voltage setting.
Table 1: KV1 and KV2 Switch Settings
KV1 Air KV2 Air Output Voltage (kV)
OFF OFF 60
OFF ON 50
ON OFF 40
ON ON 35