Introduction; How The Pro Aa5500Sc Electrostatic Air-Assisted; Airless Spray Gun Operates; Operating The Spray Function - Graco PRO AA5500SC Instruction Manual

How the PRO AA5500sc Electrostatic
Air-Assisted Airless Spray Gun Operates
(Refer to page 6)
WARNING
INJECTION HAZARD
This is not an air spray gun. To reduce
the risk of an injection injury, read and
follow the Warnings on pages 2 and 3
and throughout the text of this instruction manual.
The air-assisted airless spray gun combines airless
and air spraying concepts. The spray tip (B) shapes
the fluid into a fan pattern, as does a conventional
airless spray tip. Air from the air cap (A) further atom-
izes the fluid and completes the atomization of the
paint tails into the pattern to produce a more uniform
pattern. The ability of the PRO AA5500 Electrostatic
Spray Gun to spray at higher fluid pressures provides
the additional power needed to atomize higher solids
materials.

Operating the Spray Function

Applying a minimum of 50 psi (3.5 bar, 0.35 MPa) air
pressure to the gun manifold's cylinder air fitting (which
is marked "CYL", see page 6) will retract the gun
piston, which opens the air valves and a short time
later opens the fluid needle. This provides 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, air pressure is applied to
the gun manifold's turbine air fitting (which is marked
"TA", see page 6) through a Graco electrically con-
ductive air hose. The air enters the manifold and is
directed to the inlet of the power supply turbine (H).
The air spins the turbine, which then provides electrical
power to the internal high voltage power supply (J).
The fluid is charged by the spray gun electrode (K).
The charged fluid is attracted to the nearest grounded
object, wrapping around and evenly coating all sur-
faces.

Introduction

The turbine air is exhausted into the shroud (E) and
out the back of the manifold through the fitting marked
"EXH". The exhaust air helps keep contaminants out
and helps keep the gun clean.
Switching to the Higher or Lower
kV Setting
The gun's full high voltage setting is 85 kilovolts. The
gun's spraying voltage can be reduced by switching to
the low voltage setting for spraying in areas where too
much electrostatic wrap is not desirable. Applying a
minimum of 50 psi (3.5 bar, 0.35 MPa) air pressure to
the kV switch air inlet (which is marked "KV", see page
6) will activate it and switch to the lower voltage
setting. The lower voltage is factory set to 60 kilovolts
at zero microamperes. This setting can be adjusted
from 45 to 80 kilovolts, as instructed on page 38. The
solenoid valve used to activate the kV switch must
bleed the air out of the line for the switch to draw back
to the higher voltage setting.

Gun Features and Options

D The gun is designed for use with a reciprocator,
and it can be directly mounted to a one-half inch
rod. With additional brackets, the gun can be
mounted for robotic applications.
D The gun is designed for quick-disconnect, which
enables the operator to quickly remove the spray
gun without disconnecting the air lines to the gun.
D The gun functions are activated from a separate
controller that sends the appropriate signal to the
actuating solenoids (S). See Fig. 1, page 8.
D An optional fiber optic readout system can be
installed to monitor the gun's spraying voltage. A
fiber optic cable (KK) connected to the gun man-
ifold carries the signal from the gun to a remote ES
(electrostatic) display module. See Fig. 2, page 8.
An ES Display Module (GG), P/N 224117, is avail-
able and will display the gun's spraying voltage and
current. A battery operated ES Display Module
(FF), P/N 189762, is also available; it displays the
gun's spraying voltage only.
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