Graco UNICARB Pro AA4500 User manual

U.S. Patent No. 4,290,091; 4,219,865; 4,497,447; 4,462,061; 4,660,774; 5,063,350; 5,080,289; 5,289,977
Patented 1986, 1987 Canada
Brevete 1986, 1987
U.K. Patent No. 2,147,158; 2,142,559B; 2,140,327–B
Other U.S. and Foreign Patents Pending
01944A
INSTRUCTIONS–PARTS LIST 308–294
Rev. J
Supersedes G
and PCN H
85 KV ELECTROSTATIC
Model PRO AA4500 
Air-Assisted Airless Spray Gun
100 psi (7 bar) Maximum Working Air Pressure
3000 psi (207 bar) Maximum Working Fluid Pressure
For use with Class , Group D paint spray materials
Part No. 236–030, Series A
Spray Gun with basic power supply ,
2-finger trigger
Part No. 236–031, Series A
Spray Gun with full-featured power supply ,
2-finger trigger
Part No. 236–032, Series A
Spray Gun with basic power supply ,
4-finger trigger
Part No. 236–033, Series A
Spray Gun with full-featured power supply ,
4-finger trigger
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
 COPYRIGHT 1993 GRACO INC.
This manual contains important
warnings and information.
READ AND RETAIN FOR REFERENCE

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WARNINGS
High Pressure Spray Can Cause Serious Injury . For Professional Use Only .
Seriou
s i njury , e xplosion, fire o r e lectrostati c s hoc k c an occu r i f the precautions belo w a re not followed.
Read and understand all instruction manuals, tags, and warning labels before operating equipment.
Electrical equipment shall only be installed, operated, and serviced by trained, qualified personnel who
shall be fully conversant with the requirements stated within this instruction manual.
FLUID INJECTION HAZARD
General Safety
This equipment operates at very high fluid pressure. Spray
from the gun, leaks or ruptured components can inject fluid
through your skin and into your body and cause extremely
serious injury , including the need for amputation. Also, fluid
injected or splashed into the eyes or on the skin can cause
serious damage.
Never point the spray gun at anyone or at any part of the
body.
Never put hand or fingers over the spray tip.
Never try to “blow back” paint; this is not an air spray gun.
Always have the tip guard in place on the spray gun when
spraying.
Always lock the trigger safety latch when you are not
spraying.
Always follow the Pressure Relief Procedure, at right, be -
fore
cleaning or removing the spray tip or servicing any sys -
tem equipment.
Never try to stop or deflect leaks with your hand or body .
Check operation of all equipment safety devices before
each use.
Medical Alert – Airless Spray W ounds
If any fluid appears to penetrate your skin, get emergency
medical care at once. Do not treat as a simple cut. T ell the
doctor exactly what fluid was injected.
Note to Physician: Injection into the skin is a traumatic injury . It
is important to treat the injury surgically as soon as possible.
Do not delay treatment to research toxicity . T oxicity is a concern
with some exotic coatings injected directly into the blood stream.
Consultation with a plastic surgeon or reconstructive hand surgeon
may be advisable.
Spray Gun Safety Devices
Be sure all gun safety devices are operating properly before
each use. Do not remove or modify any part of the gun; this
can cause a malfunction and result in serious injury .
Trigger Safety Latch
Whenever you stop spraying, even for a moment, always set
the gun trigger safety latch in the locked position, making the
gun inoperative. See Fig 3, page 10. Failure to lock the safety
latch can result in accidental triggering of the gun.
Tip Guard
Always have the tip guard in place on the spray gun while
spraying. The tip guard alerts you to the fluid injection hazard
and helps reduce, but does not prevent, risk of accidentally
placing your fingers or any part of your body close to the
spray tip.
Diffuser (part of seat housing, item 21 in Parts List)
The gun dif fuser breaks up spray and reduces the risk of fluid
injection when the tip is not installed. Check dif fuser operation
regularly . Follow the Pressure Relief Procedure , below , then
remove the spray tip. Aim the gun into a grounded metal pail,
holding the gun firmly to the pail. Using the lowest possible
pressure, trigger the gun. If the fluid coming from the gun is
not dif fused into an irregular stream, replace the dif fuser
immediately.
Spray T ip Safety
Use extreme caution when cleaning or changing spray tips. If
the spray tip clogs while spraying, lock the trigger safety latch
immediately . Always follow the Pressure Relief Procedure,
below , and then remove the spray tip to clean it. Never wipe
of f build-up around the spray tip or air cap until pressure is
fully relieved and the trigger safety latch is locked.
Pressure Relief Procedure
To reduce the risk of serious injury , including fluid injection,
splashing in the eyes or on skin, or electrostatic shock, al -
ways follow this procedure whenever the pump is shut of f,
when checking or servicing any part of system, when install -
ing or changing spray tips and whenever you stop spraying.
1. Lock the spray gun trigger safety latch.
2. T urn the gun’ s ES ON-OFF lever to the OFF position.
3. Shut of f the power to the pump.
4. Close the bleed-type master air valve (required in sys -
tem).
5.
Close the air valve for the gun air supply line.
6. Unlock the gun trigger safety latch.
7. T rigger the gun into a grounded metal waste container to
relieve fluid and air pressure.
8. Lock the gun trigger safety latch again.
9. Open the pump drain valve (required in system) to help
relieve fluid pressure in the displacement pump. In addi -
tion, open the drain valve connected to the fluid pressure
gauge (in a system with fluid regulation) to help relieve
fluid pressure in the hose and gun. T riggering the gun to
relieve pressure may not be suf ficient. Have a container
ready to catch the drainage.
10. Leave the drain valve(s) open until you are ready to spray
again.
If you suspect that the spray tip or hose is completely
clogged or that pressure has not been fully relieved after fol -
lowing the steps above, v ery slowly loosen the hose end cou -
pling and relieve pressure gradually , then loosen completely .
Now clear the tip or hose obstruction.

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FIRE, EXPLOSION OR ELECTROSTA TIC SHOCK HAZARD
To reduce the risk of fire, explosion, or electrostatic shock,
which may result from electrical discharge, it is essential that:
S All parts of the electrostatic system are properly grounded.
S All personnel in or close to the spray area are properly
grounded.
S All electrically conductive objects or devices in the spray
area, including paint containers, wash cans and tools, are
properly grounded.
When operating the electrostatic device, any ungrounded
objects in the spray area (such as people, containers, tools,
etc.) can become electrically charged. Arcing may occur if
these objects then come in contact or close to ground. Arcing
of suf ficient energy levels can ignite the fluid being sprayed,
fumes from solvents, dust particles, and other flammable sub -
stances.
This can cause a fire, explosion, or electrostatic
shock and result in serious injury and property damage.
Static electricity can also be generated by the flow of fluid
through the pump, hose, gun, and nozzle, but it is dissipated
through proper grounding as described in Grounding below .
If you experience any arcing or feel even a slight shock, stop
spraying immediately . Check for proper grounding of the
entire system. Be sure you have corrected the problem
before starting to spray again.
Grounding
The following are minimum requirements for grounding a
basic electrostatic system. Y our system may include other
equipment or objects which must also be grounded. Always
check your local electrical code for detailed grounding in -
structions. Be sure your system is connected to a true earth
ground.
1.
Pump: ground by using a ground wire and clamp as
described in your separate pump instruction manual.
2. Air compressors and hydraulic power supplies: ground
according to the manufacturer ’ s recommendations.
3. Electrostatic Air Spray Gun: obtain grounding through
connection to a properly grounded air supply hose. Use
only the Graco Electrically Conductive Air Supply Hose;
see
ACCESSORIES section to order . Connect the air
hose ground wire to a true earth ground.
4. All air and fluid lines must be properly grounded. Use only
grounded hoses with a maximum of 500 feet (150 m)
combined hose length to ensure grounding continuity:
Refer also to Hose Grounding Continuity on page 4.
5. All electric cables must be properly grounded.
6. Object being sprayed: keep the workpiece hangers clean
and grounded at all times. Contact points must be sharp
points or knife edges.
7. All electrically conductive objects or devices in the spray
area, including paint containers and wash cans, must be
properly grounded.
8. All persons entering the spray area: shoes must have
conductive soles, such as leather
, or personal grounding
straps must be worn. Rubber or plastic soles are not con -
ductive. The operator must not wear gloves that insulate
the hand from the spray gun. The gloves must be conduc -
tive or modified as shown in Fig 2, page 9.
9. The floor of the spray area must be electrically conductive
and grounded. Do not cover the floor with cardboard or
any non-conductive material which would interrupt
grounding continuity .
10.
Flammable liquids in the spray area must be kept in
approved, grounded containers. Do not store more than
the quantity needed for one shift.
11. All solvent pails: use only grounded metal pails, which are
conductive. Do not place the pail on any non-conductive
surface, such as cardboard or paper , which would inter -
rupt grounding continuity .
Flushing and Cleaning Safety
To reduce the risk of fluid injection injury , static sparking or
splashing, always follow the Pressure Relief Procedure on
page 2 and remove the spray tip before flushing. Use the
lowest possible pressure to flush. T rigger the gun into a
grounded metal waste container .
Be sure the ES ON-OFF lever is OFF before flushing or
cleaning any part of the spray system.
To flush or purge equipment, always use solvents with a flash
point equal to or greater than that of the fluid being sprayed.
T o clean the exterior of the equipment, always use solvents
with a flash point of higher than 100 _ F (38 _C).
Always
remove all solvent from the system before reactivat -
ing the spray gun.
Use only non-sparking tools to clean residue from the booth
and hangers.
Ventilate the Spray Booth
To prevent hazardous concentrations of toxic and/or flam -
mable vapors, spray only in a properly ventilated spray booth.
Check and follow all National, State and Local codes regard -
ing air exhaust velocity requirements. Check and follow all
local safety and fire codes and OSHA standard 1910.107.
Never operate the spray gun unless the ventilating fans are
operating.

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EQUIPMENT MISUSE HAZARD
General Safety
Any misuse of the spray equipment or accessories, such as
over pressurizing, modifying parts, using improper replace -
ment parts, using incompatible chemicals and fluids, or using
worn or damaged parts, can cause them to rupture and result
in serious injury , including fluid injection and splashing fluid in
the eyes or on the skin, or in fire, explosion or property dam -
age.
Only use genuine Graco replacement parts when servicing
the gun. Do not mix or use other PRO Gun parts that may
look similar
, but have dif ferent part numbers!
Never alter or modify any part of this equipment; doing so
could cause it to malfunction.
Check the gun and all spray equipment regularly and repair
or replace worn or damaged parts immediately
.
W
ear hearing protection when operating this equipment.
Read and follow the fluid and solvent manufacturer ’ s litera -
ture regarding the use of protective eyewear , gloves, clothing,
respirator and other equipment.
Fluid Compatibility
Be sure all fluids and solvents used are chemically compat -
ible with the “W etted Parts” shown in the TECHNICAL DATA
on the back cover
. Always read the fluid and solvent man -
ufacturer’
s literature before using fluid or solvent in this gun.
System Pressure
The PRO AA4500 electrostatic spray gun has a 3000 psi
(207 bar) Maximum Working Fluid Pressure and 100 psi (7
bar) Maximum Working Air Pressure . Never exceed these
pressures!
The high pressure fluid supply pump must be limited so that it
is not capable of producing a fluid pressure greater than the
maximum working fluid pressure of the spray gun or any
other system component.
Be sure that all spray equipment and accessories added to
the spray system are properly rated to withstand maximum
working pressure of your system. Do not exceed maximum
working pressure of any component or accessory used in the
system.
HOSE SAFETY
High pressure fluid in the hoses can be very dangerous. If the
hose develops a leak, split or rupture due to any kind of wear ,
damage or misuse, the high pressure spray coming from it
can cause a fluid injection injury or other serious injury or
property damage.
All fluid spray hoses must have a spring guard on both ends!
The spring guards help protect the hose from kinks or bends
at or close to the coupling which can result in hose rupture.
TIghten all fluid connections securely before each use. High
pressure fluid can dislodge a loose coupling or allow high
pressure spray to come out of the coupling.
Never use a damaged hose. Before each use, check the
entire hose for cuts, leaks, abrasion, bulging cover , or dam -
age or movement of the hose couplings. If any of these con -
ditions exist, replace the hose immediately . Do not try to
recouple high pressure hose or mend it with tape or any other
device. A repaired hose cannot contain the high pressure
fluid.
Handle and route hoses carefully . Do not pull on hoses to
move equipment. Do not use fluids or solvents which are not
compatible with the inner tube and cover of the hose. Do not
expose Graco hose to temperatures above 180  F (82  C)
or below –40  F (–40  C).
Hose Grounding Continuity
Proper hose grounding continuity is essential to maintaining a
grounded spray system. Check the electrical resistance of
your air and fluid hoses at least once a week. If your fluid
hose does not have a tag on it which specifies the maximum
electrical resistance, contact the hose supplier or manufac -
turer for the maximum resistance limits. Use a resistance
meter in the appropriate range for your hose to check the
resistance. If the resistance exceeds the recommended lim -
its, replace it immediately . An ungrounded or poorly grounded
hose can make your system hazardous. Also read FIRE, EX-
PLOSION, OR ELECTROSTATIC SHOCK HAZARD
on
page 2.
IMPORTANT
United States Government safety standards have been adopted under the Occupational Safety and Health Act. These standards––particularly the
General Standards, Part 1910.107 and any other appropriate regulations––should be consulted in connection with the installation, operation, and
maintenance of electrostatic spray painting equipment.

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Table of Contents
Warnings 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Terms 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gun Setup 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Daily Gun Care, Flushing, and Cleaning 16. . . . . . .
Spray Pattern T roubleshooting 21. . . . . . . . . . . . . . . .
Gun Operation Troubleshooting 22. . . . . . . . . . . . . . .
Electrical Troubleshooting 23. . . . . . . . . . . . . . . . . . . .
Electrical Tests
T
est Gun Resistance 25. . . . . . . . . . . . . . . . . . . . . . . .
Test Power Supply Resistance 25. . . . . . . . . . . . . . . .
Test Barrel Resistance 26. . . . . . . . . . . . . . . . . . . . . . .
Service
Read
This Page Before Servicing the Gun 27. . . . . .
Air Cap, Spray T ip, or Seat Housing
Replacement 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrode Replacement 29. . . . . . . . . . . . . . . . . . . . . .
Fluid T ube Removal and Replacement 30. . . . . . . . .
Fluid Filter Removal 30. . . . . . . . . . . . . . . . . . . . . . . . .
Barrel Removal 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Barrel Installation 32. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Packing Adjustment 33. . . . . . . . . . . . . . . . . . . .
Fluid Needle Removal 33. . . . . . . . . . . . . . . . . . . . . . .
Power Supply Removal & Replacement 34. . . . . . . .
Power Supply Adjustment,
Gun Part No. 236–031 Only 34. . . . . . . . . . . . . . . .
Turbine Alternator Removal & Replacement 35. . . .
ES ON-OFF V alve Repair 35. . . . . . . . . . . . . . . . . . . .
Fan Air Adjustment V alve Repair 36. . . . . . . . . . . . . .
Air V alve Repair 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts 38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories 40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Graco Phone Numbers 42. . . . . . . . . . . . . . . . . . . . . . .
Spray T ip Selection Chart 43. . . . . . . . . . . . . . . . . . . . .
Technical Data Back Cover . . . . . . . . . . . . . . . . . . . . . . .
Warranty Back Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Terms
WARNING: Alerts user to avoid or correct conditions that
could cause bodily harm.
CAUTION: Alerts user to avoid or correct conditions that
could cause damage to or destruction of
equipment.
NOTE: Identifies essential procedures or helpful
information.

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Introduction
How the PRO AA4500 Electrostatic
Air-Assisted Airless Spray Gun Operates
WARNING
Remember, this is not an air spray gun; for your
safety be sure to read and follow the W arnings on
pages 2 to 4 and throughout the text of this
instruction manual.
The air-assisted airless spray gun combines airless
and air spraying concepts. The spray tip shapes the
fluid into a fan pattern, as does a conventional airless
spray tip. Air from the air cap further atomizes the fluid
and completes the atomization of the paint tails into
the pattern to produce a more uniform pattern.
As the gun is triggered, the regulated air is directed to
the air cap for the air-assist function and air is also
directed to the power cartridge turbine.
The regulated air that is directed to the air cap can be
further controlled using the gun’ s air control valve. This
valve can be used to restrict air flow to the air cap
while maintaining suf ficient air flow to the turbine. The
air control valve does not control pattern width. T o
change pattern width, a new tip size must be used.
The ability of the PRO AA4500 Electrostatic Spray
Gun to spray at higher fluid pressures provides the
additional power needed to atomize higher solids
materials.
The gun’ s internal power cartridge provides high volt -
age current. The fluid is electrostatically charged as it
passes the gun’ s electrode. The charged fluid is
attracted to the grounded object, wrapping around and
evenly coating all surfaces.
NOTE: The gun’ s air control valve can be completely
turned of f to have airless atomization if desired. Clos -
ing the air control valve does not ef fect the operation of
the turbine.
Power Supply’ s Adjustable Lower V oltage Setting
The gun’ s lower voltage setting (LO) is adjustable. The
LO setting can be adjusted from 45 to 80 kV ; it is pre -
set by the factory at 60 kV . See page 34 to change the
setting. NOTE: The gun’s full (HI) voltage setting is 85
kV.
Part No. 236–031 and 236–033,
with Full-Featured Power Supply
This full-featured power supply includes a radio fre -
quency (RF) transmitter . The transmitter sends a sig -
nal to a hand held spray voltage readout monitor ,
called an SVR. The SVR readout is the actual spray
voltage. A jumper pin is provided with the SVR and
must be installed in the gun’ s power supply before the
gun will transmit a signal. See ACCESSORIES to or-
der the SVR.
Part No. 236–030 and 236–032,
with Basic Power Supply
The basic power supply provided with Gun P/N
236–030 does not include the RF transmitter capability .
01947
Air Control
Valve
ES Indicator
Light
ES HI-LO
Lever
ES ON-OFF
Lever
T rigger Safety
Latch
Tip Guard
(orange)
Air
Cap
(orange)
Spray
Tip
(orange)
Retaining
Nut
Back V iew of Gun
01944A

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Installation
KEY
A* Bleed-type Air Shutof f V alve
B
Air Line Filter
C* Pump Air Regulator
D Air Line Lubricator
E Pump Runaway V alve
F Pump
G*
Pump Ground Wire
H Fluid Shutof f V alve
J*
Fluid Pressure Regulator
K Pressure Gauge
L* Grounded Fluid Hose
with spring guards
M Gun Fluid Inlet (1/4 npsm)
N Gun Air Regulator
P Gun Air Shut-of f V alve
Q*
Graco Electrically Conductive
Air Supply Hose
(1/4 npsm x 1/4 npsm LH)
R* Fluid Drain V alve
S
Fluid Filter
T Pump Fluid Inlet
W PRO AA4500 Spray Gun
X Gun Air Inlet (1/4 npsm LH)
* Equipment required for safe operation of
system. Must be purchased separately .
See ACCESSORIES.
Fig. 1
A
CA
B
E
F
G
H
J
K
S
R
T
L
N
P
Q
M
R
D
WARNING
SIGN
W
X
01945A
The typical installation shown in Fig. 1 is only a guide
for selecting and installing electrostatic air-assisted
airless spray systems. It is not an actual system
design. The particular type and size system for your
operation must be custom designed for your needs.
For assistance in designing a system, contact your
Graco representative.
Warning Signs
Mount warning signs in the spray area where they can
easily be seen and read by all operators. An English
W arning Sign is provided with the gun. Additional
English, French, German, and Spanish signs are avail -
able at no charge. See Accessories to order them.
WARNING
Installing and servicing this equipment requires
access to parts which may cause electrostatic
shock or other serious injury if work is not per -
formed properly .

Do not install or service this equipment unless
you are trained and qualified.
 Be sure your installation complies with National,
State and Local codes for the installation of
electrical apparatus in a Class  , Group D Haz -
ardous Location.
 Check and follow all local safety and fire codes,
NFP A 33, NEC 504 and 516, and OSHA stan -
dard 1910.107.

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Installation
Ventilate the Spray Booth
WARNING
To prevent hazardous concentrations of toxic and/
or flammable vapors, spray only in a properly venti -
lated spray booth. Never operate the spray gun
unless ventilation fans are operating.
Electrically interlock the gun air supply with the ventila -
tors to prevent gun operation without ventilating fans
operating. Check and follow all National, State, and
Local codes regarding air exhaust velocity
requirements.
NOTE:
High velocity air exhaust will decrease the
operating ef ficiency of the electrostatic system. Air ex -
haust velocity of 100 ft/min (31 linear meters/minute)
should be suf ficient.
Air Line Accessories (Refer to Fig. 1)
1. Install an air shut-of f valve ( P) on each gun air
supply line (Q) to shut of
f air to the gun(s).
2. Install an air regulator (N) on the gun air supply
line to control air pressure to the gun.
3. Install an air line filter (B) on the air supply line to
ensure a dry , clean air supply to the gun. Dirt and
moisture can ruin the appearance of your finished
work-piece and can cause the gun to malfunction.
4. Install a bleed-type air regulator (C) on the pump
air supply line to control air pressure to the pump.
WARNING
T o reduce the risk of serious injury due to compo -
nent rupture, pump pressure must be limited by
the pump air regulator . Do not rely on the gun fluid
regulator to limit the fluid pressure to the gun.
The fluid supply pump must be prevented from pro -
ducing a fluid pressure greater than the 3000 psi
(207 bar) Maximum Working Pressure of the spray
gun. For example, the air supply pressure to a 30:1
pump must not exceed 100 psi (7 bar).
WARNING
T o reduce the risk of serious injury due to compo -
nent rupture, be sure that all spray equipment and
accessories added to the spray system are prop -
erly rated to withstand the maximum working pres -
sure of your system.
5. Install a bleed-type air shutof f valve (A) on the
main air line and the pump air line to shut of f air to
the pump. Install an additional bleed-type valve on
each pump air supply line to relieve air trapped
between this valve and the pump after the air regu
-
lator is shut of f.
WARNING
The bleed-type air shutoff valve (A) is required in
your system to relieve air trapped between this
valve and the pump after the air regulator is closed.
T rapped air can cause the pump to cycle unexpect -
edly
, which could result in serious bodily injury ,
including splashing in the eyes or on the skin and
injury from moving parts.
6. Install an air line lubricator (D) as close to the
pump (F) as possible.
Fluid Line Accessories (Refer to Fig. 1)
1. Install a fluid filter (S) and drain valve (R) at the
pump outlet. Filtering the fluid will help remove
coarse particles and sediment that could clog the
spray tip.
WARNING
The fluid drain valve (R) is required in your system
to assist in relieving fluid pressure in the displace -
ment pump, hose and gun; triggering the gun to
relieve pressure may not be suf ficient. Install a
drain valve close to the pump’ s fluid outlet. The
drain valve reduces the risk of property damage or
serious bodily injury , including splashing in the eyes
or on the skin and contamination from hazardous
fluids.
2.
Install a fluid regulator (J) on the fluid line to con -
trol fluid pressure to the gun.

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Operation
Operating Checklist
Check the following list daily , before starting to operate
the system, to help ensure safe, ef ficient operation.
1. Be sure all operators are properly trained to
safely operate an electrostatic air-assisted
airless
spray system.
2. Be sure all operators are trained how to prop -
erly and completely relieve system pressure,
using the Pressure Relief Procedure on
page
10.
3. Be sure the system is thoroughly grounded.
See FIRE, EXPLOSION OR ELECTRO-
STATIC SHOCK HAZARD on page 3, and
Check the Electrical Grounding on
page 1 1.
4. Be sure the warning sign provided with the gun
is mounted in the spray area where it can be
easily
seen and read by all operators.
5. Be sure the operator and all persons entering
the spray area are properly grounded by wear -
ing shoes with conductive soles or personal
grounding
straps.
6. Operator must not wear gloves which insulate
the hand from the spray gun. If worn, gloves
must be conductive or modified as shown in
Fig. 2 so as not to interfere with operator
grounding
through the gun.
7. Be sure ventilation fans are operating
properly.
8. Be
sure the work-piece hangers are clean and
grounded. Contact points must be sharp
points
or knife edges.
9. Be sure all refuse and non-essential equip-
ment
is removed from the spray booth.
10. Be sure all flammable liquids in the spray
booth
are in approved, grounded containers.
11. Be sure all electrically conductive objects in
the
spray area, including paint containers and
wash cans, are properly grounded and the
floor
of the spray area is electrically conductive
and grounded.
WARNING
The wallet sized warning card 179–960, provided
with the gun, should be available and easily
accessible at all times for anyone operating or
servicing this equipment. The card contains impor -
tant information on what to do if a fluid injection
injury occurs. Additional cards are available at no
charge from Graco.
Fig. 2
3 in. (76 mm)
Square Cut Out
and Finger of
Glove Cut Off
NOTE: If gloves are worn,
they must be conductive or
modified as shown so as not
to interfere with operator
grounding through the gun.

10308-294
Operation
WARNING
Pressure Relief Procedure
T o reduce the risk of serious injury , including fluid
injection, splashing in the eyes or on skin, or elec -
trostatic shock, always follow this procedure when -
ever the pump is shut of f, when checking or servic -
ing any part of system, when installing or changing
spray tips and whenever you stop spraying.
1. Lock the spray gun trigger safety latch. See
Fig. 3.
2. T urn the gun’ s ES ON-OFF lever to the OFF
position.
3.
Shut of f the power to the pump.
4. Close the bleed-type master air valve (required
in system).
5. Close the air valve for the gun air supply line.
6. Unlock the gun trigger safety latch.
7. T rigger the gun into a grounded metal waste
container to relieve fluid and air pressure.
8. Lock the gun trigger safety latch again.
9. Open the pump drain valve (required in sys -
tem) to help relieve fluid pressure in the dis -
placement pump. In addition, open the drain
valve connected to the fluid pressure gauge (in
a system with fluid regulation) to help relieve
fluid pressure in the hose and gun. T riggering
the gun to relieve pressure may not be suf fi-
cient. Have a container ready to catch the
drainage.
10.
Leave the drain valve(s) open until you are
ready to spray again.
If you suspect that the spray tip or hose is com -
pletely clogged or that pressure has not been fully
relieved after following the steps above, v ery slowly
loosen the hose end coupling and relieve pressure
gradually , then loosen completely . Now clear the tip
or hose obstruction.
Fig. 3
T
rigger Safety
Latch Unlocked
T
rigger Safety
Latch Locked 01988A

308-29411
Gun Setup
1. Complete the Operating Checklist and
follow the Warnings on pages 9 and 10.
2. Connect the Graco air hose.
WARNING
To reduce the risk of electrostatic shock or other
serious injury, the air supply hose must be electri -
cally connected to a true earth ground. Use Only
Graco Electrically Conductive Air Supply Hose.
NOTE: The Graco air hose and the gun have special
left-hand threads to prevent connecting another type of
air supply hose to the gun air inlet and is available in
lengths ranging from 6 to 100 feet (1.83 to 30.5 m).
See Accessories to order the hose.
A. Connect the 1/4 npsm(f) left-hand end of the
Graco conductive air supply hose (A) to the gun air
fitting (17).
A
Fig. 2A
01989A
17
left-hand
thread
B. Connect the other end of the air supply hose (A) to
a filtered and regulated air supply line (B).
C. Connect the air supply hose ground wire (C) to a
true earth ground.
B
Fig. 2B-C
01990
C
A
NOTE: T
o connect two or more air hoses, use air
adapter nipple 185–493. See Accessories.
3. Check the gun’s electrical grounding.
WARNING
Proper electrical grounding of every part of your
system is essential. For your safety , read the warn -
ing section, FIRE, EXPLOSION, OR ELECTRO -
STA
TIC SHOCK HAZARD , on page 3. Ground
the system as explained there. Then check the gun
as explained below .
A.
Have a qualified electrician check the electrical
grounding continuity of the spray gun and air hose,
using the accessory Graco megohmmeter (E). Use
an applied voltage of 500 minimum to 1000 volts
maximum.
B.
With the fluid and air supply turned of f and the
gun’ s ES ON-OFF Lever turned to OFF , set the
megohmmeter to the “20M” scale and measure the
resistance between the gun handle (7) and a true
earth ground (D).
01946A
E
A
Fig. 3B
D
7
C.
If the resistance is greater than 2 megohms*,
check the tightness of the ground connections, and
be sure the air supply hose ground wire is con -
nected to a true earth ground. If the resistance is
still greater than 2 megohms*, replace the air sup -
ply hose.
* If you are using the red colored conductive air
hose, resistance should not exceed 100 ohms.

12308-294
Gun Setup
4. Connect the gun exhaust tube.
Press the exhaust tube (56) onto the barbed adapter
on the bottom of the gun handle. Secure the tube with
the clamp (57) provided.
Fig. 4 01992A
56
57
5. Connect the fluid hose.
A. Before connecting the fluid line, blow it out with air
and flush it with solvent. Use solvent which is com -
patible with the fluid to be sprayed.
B. Connect the static-free fluid hose (F) to the 1/4–18
npsm (R1/4–19) gun fluid fitting (10).
Fig. 5B
01993A
F
10
NOTE: The PRO AA4500 spray gun has a 100 mesh
in-line fluid inlet filter . A 60 mesh filter is also available.
See Accessories.
C.
Connect the other end of the fluid hose (F) to a
grounded, filtered, and regulated fluid line (G).
G
Fig. 5C
01994A
F
6. Flush the spray gun.
Before running any paint through the spray gun, make
sure the trigger safety latch is in the locked position,
and the ES ON-OFF lever is turned to OFF , then
remove the spray tip. Flush the gun out with a solvent
that is compatible with the fluid to be sprayed, using
the lowest possible pressure.
7. Follow the Pressure Relief Procedure.
WARNING
To reduce the risk of a fluid injection injury , always
follow the Pressure Relief Procedure on page 10
before removing or installing the spray tip, air cap
or tip guard.
8. Select a spray tip.
The fluid output and pattern width depend on the size
of the spray tip, the fluid viscosity , and the fluid pres -
sure. Use the Spray T ip Selection Chart on page 43,
as a guide for selecting an appropriate spray tip for
your application.

308-29413
Gun Setup
9. Install the spray tip.
A. With the pressure relieved, trigger safety latch
locked, and ES ON-OFF lever OFF , place the
spray tip (9) in the air cap (1), aligning the tab of
the tip with the groove in the air cap. Be careful
not to bend the electrode wire.
WARNING
T o reduce the risk of electrostatic shock or explo -
sion, never operate the spray gun with a bent,
damaged or missing electrode.
Fig. 9A
01995
9
1
B.
Install the spray tip (9) and air cap (1), tip guard
(2), and retaining nut (8) onto the gun; tighten the
retaining nut firmly .
T
o avoid damaging the tip guard (2), orientate the
air cap (1) before tightening the retaining nut (8).
Do not turn the air cap when the retaining nut is
tight.
CAUTION
8
Fig. 9B
02088A
2
1, 9
10.Set the air pressure.
A. Close
the air control valve (43) by turning it fully
clockwise.
B. T
urn the ES ON-OFF lever (26) to ON.
Fig. 10A-B
01947
26
ON
43
close
C. Make sure the fluid supply is shut of f.
D. T
rigger the gun and adjust the air pressure with the
gun air regulator (H); use the Recommended Air
Hose Inlet Pressure chart, below , as a guide.
Fig. 10D
01997
H
Recommended Air Hose Inlet Pressure
Air Hose Length
Recommended Air
Hose Inlet Pressure
6 ft ((1.8 m) 40 psi (2.8 bar)
15 ft (5 m) 43 psi (3.0 bar)
25 ft (8 m) 45 psi (3.1 bar)
36 ft (1 1 m) 47 psi (3.2 bar)
50 ft (15 m) 50 psi (3.5 bar)
75 ft (23 m) 55 psi (3.8 bar)
100 ft (30.5 m) 60 psi (4.1 bar)
NOTE: Using higher than recommended air pressures
can reduce the life of the turbine/alternator
. Lower
pressures can be used but may reduce electrostatic
wrap.

14308-294
Gun Setup
11. Set the atomization fluid pressure.
NOTE: Atomization fluid pressure will vary based on
the viscosity of the fluid, the flow rate desired, and oth -
er characteristics of your system.
Atomization Chart
Fluid V iscosity
Starting Fluid
Pressure
Fluid Pressure
Increments
40 or more
seconds in #2
Zahn cup*
1500 psi
(105 bar)
200 psi
(14 bar)
25–40 seconds
in #2 Zahn
cup**
1000 psi
(70 bar)
100 psi
(7 bar)
25 or less
seconds in #2
Zahn cup***
500 psi
(35 bar)
100 psi
(7 bar)
* Includes fluids with 60% volume solids or greater .
Examples: high-build high-solids protective urethanes and
epoxies
** Includes fluids with 40 to 60% (medium) volume solids.
Examples: alkyd enamels, some protective urethanes and
epoxies
*** Includes fluids with 40% volume solids or less.
Examples: stains, lacquers, and decorative urethanes
A. Close the air control valve (43) by turning it fully
clockwise and turn the ES ON-OFF lever (26) to
OFF.
Fig. 11A 01998
26
OFF
43
close
B. Set the fluid pressure with the fluid regulator (J),
based on the Starting Fluid Pressure in the Atom-
ization Chart at left for the type of fluid you are
spraying.
Fig. 11B
J
01999A
C. With the ES ON-OFF lever OFF and the air control
valve closed, spray a test pattern across a piece of
paper , holding the gun 12 inches (305 mm) from
the surface.
Without being concerned about the presence of
“tails”, note the particle size.
D. Increase the fluid pressure by the Fluid Pressure
Increment shown in the Atomization Chart for the
type of fluid you are spraying.
E. Spray another test pattern across a piece of paper .
F.
Without being concerned about the presence of
“tails”, compare the particle size of the two test
patterns.
A decrease in particle size indicates improved at -
omization.

308-29415
Gun Setup
11 Set the atomization fluid pressure.
(continued)
G. Continue to increase the fluid pressure by the
increments shown in the chart until the particle
size no longer reduces in size; do not exceed the
gun’ s Maximum Fluid Pressure of 3000 psi (207
bar).
When the particle size no longer reduces in size,
the pattern is atomized at the lowest possible fluid
pressure, but will still have tails.
H. T o eliminate the tails, gradually open the air control
valve, by turning it counterclockwise, until there
are no tails in the pattern.
Fig. 11H

No Air Too Little Air Right Amount
of Air
01998
43
open
12.Turn the ES ON-OFF lever (26) to ON.
13.Use the ES HI-LO lever (43g)
to change
to either full voltage (HI) or a lower volt-
age level (LO).
Fig. 12-13
01947
26
ON
43g
HI
K
The LO setting is factory set to 60 kV . This setting can
be adjusted between 45 and 80 kV. See page 34 to
adjust.
NOTE: When spraying, the ES indicator light (K) will
glow , indicating the electrostatic charge.

16308-294
Daily Gun Care, Flushing, and Cleaning
WARNING
To reduce the risk of serious injury , including fluid
injection, splashing in the eyes or on the skin or
electrostatic shock, always follow the Pressure
Relief Procedure W arning on page 10 when shut -
ting off the system, when you stop spraying and
before checking, servicing, installing, cleaning or
changing any part in the system.
CAUTION
Clean all parts with a non-conductive solvent, com -
patible with the fluid being sprayed. Conductive
solvents can cause the gun to malfunction.
Methylene chloride is not recommended as a flush -
ing or cleaning solvent with this gun as it will dam -
age nylon components.
CAUTION
Solvent left in gun passages could result in a poor quality paint finish and may draw current and reduce the
electrostatic ef fect. Solvent in the power supply cavity can reduce the alternator life. Do not use any cleaning
method which may allow solvent into the gun air passages.
Do not point the gun up while cleaning it.
Do not immerse the gun in solvent.
Do not wipe the gun with a cloth soaked in
solvent; ring out the excess.
Do not use metal tools to clean the air cap holes
as this may scratch them, and make sure the
electrode wire is not damaged. Scratches in the air
cap holes or a damaged electrode wire can distort
the spray pattern.
02000 02001
0202702028
General System Maintenance
1. Clean the fluid and air line filters daily .
2.
Check all of the work hangers for material build-up;
clean them if necessary .
3.
Check for any fluid leakage from the gun and fluid
hoses. T ighten fittings or replace equipment as
needed.
4.
Flush the gun before changing colors and when -
ever you are done operating the gun.
WARNING
To reduce the risk of fire, explosion, or electrostatic
shock,
be sure the ES ON-OFF lever is turned to OFF
before flushing the gun.

308-29417
Daily Gun Care, Flushing, and Cleaning
1. Follow the Pressure Relief Procedure
Warning on page 10.
2. Make sure the ES ON-OFF lever is
turned to OFF and the trigger safety
latch is locked before proceeding.
Fig. 2
02002A
ES
OFF
locked
3. Pointing the gun down, unscrew and
remove the retaining nut (8), tip guard
(2), air cap (1) and fluid tip (9).
You may have to turn the air cap with the tip guard
to remove the air cap from the gun. Set these
parts aside.
Fig. 3 02004A
8
2
19
4. Make sure the air and coating supply is
turned off. Turn on the solvent supply.
Fig. 4
01999A
5. Flush the Spray Gun.
Unlock the trigger safety latch, point the gun down
into a grounded metal container , and flush the gun
with solvent until it is clean. Use the lowest pos -
sible fluid pressure when flushing.
Fig. 5 02005A
6. Lock the trigger safety latch and turn
off the solvent supply.
7. Follow the Pressure Relief Procedure
Warning on page 10.

18308-294
Daily Gun Care, Flushing, and Cleaning
8. Make sure the trigger safety latch is
locked, then disconnect the solvent
and air supply hoses from the gun.
02341 02338
Fig. 8
F A
9. Unlock the trigger safety latch and trig-
ger the gun into a grounded metal con-
tainer to drain the fluid tube.
Fig. 9
02006
L
10.Lock the trigger safety latch.
11. Dip the end of a soft-bristle brush into
a compatible solvent. Then point the
gun down and clean the front with the
brush and solvent.
01948
02007
Fig. 1 1
12.Dampen a soft cloth with solvent and
wring-out the excess. Point the gun
down and wipe off the outside.
Fig. 12
02008

308-29419
Daily Gun Care, Flushing, and Cleaning
13.Remove the bottom fluid tube fitting
(P) and filter (14). Clean the filter in a
compatible solvent.
14.Reinstall the filter and fitting. Do not
over-tighten and make sure the top
fluid tube fitting (Q) remains tightened.
Fig. 13–14
02009
P
14
Q
15.Hang up the gun.
Fig. 15
02010A
CAUTION
Always hang the gun with its nozzle pointing down
to avoid having solvent run into the gun air pas -
sages. Solvent in the gun air passages can cause
poor atomization and excessive current demands
and can damage the gun.
16.Clean the retaining nut, tip guard, air
cap and fluid tip with a soft brush dai-
ly, minimum.
Clean the parts with a soft brush and replace them
if they are damaged. Be careful not to bend, dam -
age, or disengage the electrode wire.
Fig. 16 02011
17.Wipe off the parts with a dry cloth. Be
careful not to bend the electrode wire.
18.Check the electrode wire. Replace it if
it is bent or damaged. See page 29.
WARNING
To reduce the risk of electrostatic shock or explo -
sion,
never operate the spray gun with a bent,
damaged or missing electrode.


Daily Gun Care, Flushing, and Cleaning
19.Place the spray tip (9) in the air cap (1).
Align the tab of the tip with the groove in the air
cap. Be careful not to bend the electrode wire.
WARNING
T o reduce the risk of electrostatic shock or explo -
sion, never operate the spray gun with a bent,
damaged or missing electrode.
Fig. 19 01995
9
1
20.Install the spray tip (9) and air cap (1),
tip guard (2), and retaining nut (8).
Tighten the retaining nut firmly.
To avoid damaging the tip guard (2), orientate the
air cap (1) before tightening the retaining nut (8).
Do not turn the air cap when the retaining nut is
tight.
CAUTION
8
02088A
2
1, 9
Fig. 20
21.Hang up the gun until it is used again.
Fig. 21
02012B
CAUTION
Always hang the gun with its nozzle pointing down
to avoid having solvent run into the gun air pas -
sages. Solvent in the gun air passages can cause
poor atomization and excessive current demands
and can damage the gun.