Graco Series A Operation manual

308–452
Rev. C
Supersedes Rev B
and PCN C
First choice when
quality counts. 
INSTRUCTIONS-PARTS LIST
INSTRUCTIONS
This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.
HUSKY307, PAIL MOUNT
PRO 3500 Electrostatic Package
See the Data Sheet, 305–666, for application information
100 psi (0.69 MPa, 6.9 bar) Maximum Fluid Working Pressure
100 psi (0.69 MPa, 6.9 bar) Maximum Air Inlet Pressure
Model 237–415, Series A
Complete package includes pump, gun with .059 in.
(1.5 mm) fluid nozzle, pail cover , 25 ft. (7.6 m) air and
fluid hoses, air and fluid controls, and fluid feed.
IMPORTANT
This manual provides basic safety , installation,
and operation information for the package. For
your safety , also read the component manuals
supplied with this package before operating it.
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
COPYRIGHT 1994, GRACO INC.



Table of Contents
Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setup 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ground the System 6. . . . . . . . . . . . . . . . . . . . . . . .
System Component Information 7. . . . . . . . . . . . .
Operation 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flushing 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Data 15. . . . . . . . . . . . . . . . . . . . . . . . . . .
Warranty 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symbols
Warning Symbol
WARNING
WARNING
This symbol alerts you to the possibility of serious
injury or death if you do not follow the instructions.
Caution Symbol
CAUTION
This symbol alerts you to the possibility of damage to
or destruction of equipment if you do not follow the
corresponding instructions.
WARNING
FIRE EXPLOSION AND ELECTROSTATIC SHOCK HAZARD
Improper grounding, poor air ventilation, open flames, or sparks can cause a hazardous condition and
result in fire or explosion and serious injury .
 Electrostatic equipment must be used only by trained, qualified personnel who shall understand the
requirements stated in this instruction manual and the electrostatic gun manual.
 Ground the equipment, the object being sprayed and all other electrically conductive objects in the
spray area. Proper grounding dissipates static electricity generated in the equipment. See Ground
the System on page 6.
 If there is any static sparking while using the equipment, stop spraying immediately . Identify and
correct the problem.
 When flushing or purging electrostatic equipment, use solvents with a flash point equal to or great -
er than that of the fluid being sprayed.
T o clean the exterior of the electrostatic equipment, use solvents with a flash point higher than
100F (38 C).
 Remove all solvent from the system before reactivating the electrostatic spray gun.
 Use only non-sparking tools to clean residue from the booth and hangers.
 Spray only in a ventilated spray booth. Electrically interlock the gun air supply with the ventilators to
prevent operation of the electrostatic power supply unless ventilating fans are running.
 Do not smoke in the spray area.
 Extinguish all open flames or pilot lights in the spray area.
 Do not turn on or of f any light switch in the spray are.
 Electrically disconnect all equipment in the spray area.
 Keep the spray area free of debris, including solvent, rags, and gasoline.
 Do not operate a gasoline engine in the spray area.
W arnings are continued on the next page.

 
WARNING
PRESSURIZED FLUID HAZARD
Spray from the gun, hose leaks, or ruptured components can splash fluid in the eyes or on the skin
and cause serious injury .

Do not stop or deflect fluid leaks with your hand, glove, or rag.
 Follow the pressure relief procedure on page 9 before cleaning, checking, or servicing the
equipment.
T
ighten all fluid connections before each use.
 Check the hoses, tubes, and couplings daily . Replace parts immediately if worn, damaged, or
loose. Permanently coupled hoses cannot be repaired.
INSTRUCTIONS
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture, malfunction, or start unexpectedly and result
in a serious injury .
 This equipment is for professional use only .

Read all the instruction manuals, tags, and labels before operating the equipment.
 Use the equipment only for its intended purpose. If you are uncertain about usage, call your Graco
distributor.

Do not alter or modify this equipment. Use only genuine Graco parts and accessories.
 Check the equipment daily . Repair or replace worn or damaged parts immediately .

Do not exceed the maximum working pressure of the lowest rated system component. This pack -
age has a 100 psi (0.69 MPa, 6.9 bar) maximum working pressure.
 Use fluids that are compatible with the equipment wetted parts. See the T echnical Data section of
all the equipment manuals. Read the fluid manufacturer ’ s warnings.
 Route the hoses away from traffic areas, sharp edges, moving parts, and hot surfaces. Do not
expose Graco hoses to temperatures above 180 F (82 C) or below –40 F (–40C).

Do not use the hoses to pull equipment.
 Do not move pressurized equipment.
W ear hearing protection when operating this equipment.
 Comply with all applicable local, state, and national fire, electrical, and other safety regulations.
TOXIC FLUID HAZARD
Hazardous fluids or toxic fumes can cause a serious injury or death if splashed in the eyes or on the
skin, swallowed, or inhaled.
 Know the specific hazards of the fluid you are using. Read the fluid manufacturer ’ s warnings.
 Store hazardous fluid in an approved container . Dispose of the hazardous fluid according to all
local, state, and national guidelines.
W ear appropriate protective clothing, gloves, eyewear , and respirator .

If the pump diaphragm fails, hazardous fluid may be exhausted along with the air . See your sepa -
rate pump manual for further information.


Setup
CAUTION
This equipment is compatible with most water-based
materials. See the wetted parts in the Technical
Data section and your fluid and solvent manufactur -
er’
s compatibility information.
Do not use acid catalyzed materials; they are incom
-
patible with the acetal used in this pump.
I. Prepare the operator
All persons who operate the system should be trained
in the safe, efficient operation of all system compo -
nents as well as the proper handling of the chemical
coating. At a minimum, all operators should thoroughly
read the safety , installation, and operation sections of
this manual and the component manuals.
Electrostatic equipment must be used only by trained,
qualified personnel who understand the requirements
stated in this instruction manual and the electrostatic
gun manual.
II. Prepare the site
1. Use a minimum recommended 5 HP (3.7 kW) air
compressor for ef ficient operation.
2. Clear obstacles and debris that could cause an
unsafe operating environment.
3. Bring an air line from your compressed air supply
to the pump location. Be sure the air is dry and
filtered. Install a bleed-type master air valve up -
stream from the pump. When it is closed and the
pump air regulator (5a) is opened, the bleed-type
master air valve relieves all air pressure to the
system components.
4. V entilate the spray booth.
WARNING
T o prevent hazardous concentrations of toxic and /
or flammable vapors, spray only in a properly
ventilated spray booth. Never operate the spray
gun unless ventilation fans are operating.
Check and follow all of the national, state, and local
codes regarding air exhaust velocity requirements.
Fig. 1
BA
C
D
9
10 6
42
04001
KEY
Components you must supply:
A Bleed-T ype master air valve
Required for pump; order part no.
1 10–223, 1/4” npt(f)
B Air filter .
Order part no. 1 10–146, 1/4 npt(f)
C Air supply line
D Grounded 5 gallon metal pail
E Air line moisture trap
Components supplied with package:
1 Husky 307 pump
2 Electrostatic air spray gun
3 Gun fluid hose
4 Gun air hose
5a Pump air regulator
5b Gun air regulator
6 Fluid regulator
9 Pump ground wire
10 1/4” female quick disconnect coupler
3
5b
5a
1

 
Setup
III. Unpack the system
1. In addition to the assembled unit, these compo -
nents are packed loosely or separately: fluid feed
hoses, gun, and instruction manuals. These are
the manuals you should receive.
308–553 Husky 307 pump
307–912 Electrostatic air spray gun
308–325 Fluid regulator
308–167 Air regulator
IV. Setup the system
1. Connect the 1/4” female quick disconnect coupler
(10) to your air supply line.
2. Slide the suction and recirculation tube assembly
(33, 37) through the bottom of the pail cover .
3.
Insert the suction tube (33) into the elbow (26) to
its full depth (about 1/2”). Loosen the elbow nut if
the tube will not go all the way in. T ighten the nut
securely . See Fig. 2.
4. Insert the recirculation tube (37) into the connector
(36) to its full depth (about 1/4”). T ighten the nut
securely.
5.
Set the pump on a clean, empty , grounded, 5
gallon (20 liter pail).
6. Mount the gun mounting bracket on the wall. See
the gun manual 307–912. Use this bracket to hold
the gun nozzle downward when not in use.
Fig. 2
35
33
26
37
36
10

V. Connect the hoses and gun to the
system (Fig. 1)
1. Connect the special electrostatic air hose (4)
between the outlet of the gun air regulator (5b) and
the air inlet of the spray gun (2). The air hose and
gun have left hand threads.
2. Connect the fluid hose (3) between the fluid regu -
lator (6) and the fluid inlet of the spray gun (2).
These are 3/8–18 npsm swivel fittings.
3. V erify that all fittings throughout the system are
tightened securely .


Setup
VI. Ground the system
WARNING
To reduce the risk of static sparking, ground the
pump and all other equipment used or located in
the spray area. Check your local electrical code for
detailed grounding instructions for your area and
type of equipment. Ground all of this equipment.
Also read FIRE EXPLOSION AND ELEC -
TROSTA
TIC SHOCK HAZARD on page 2.
1. Pump : one end of the ground wire (9) is already
connected to the pump grounding strip. Connect
the clamp end of the ground wire to a true earth
ground.
2.
Electrostatic spray gun : grounding is obtained
through connection to a properly grounded air
supply hose. Use only Graco Electrically Conduc -
tive Air Supply hose (4) as supplied with this
system. Remove the nut and washer from the
pump grounding strip. Install the air spray gun
ground wire to the screw and reinstall the nut and
washer securely . See Fig. 3.
04090
Fig. 3
Connect
to a true earth ground

4
9

Remove nut and washer ,
connect air hose ground to the screw
and reinstall the washer and nut
3. Air compressor: according to manufacturer ’s
recommendations.
4. Object being sprayed: keep the workpiece hangers
clean and grounded at all times. Contact points
must be sharp points of knife edges. Use a me -
gohmeter or a circuit tester buzzer or light to verify
that the parts are properly grounded.
5. All electrically conductive objects or devices in the
spray area, including paint containers, wash cans.
6. All persons entering the spray area: shoes must
have conductive soles, such as leather , or person -
al grounding straps must be worn. Rubber or
plastic soles are not conductive. The operator
must not wear gloves which insulate the hand from
the spray gun. The gloves must be conductive or
modified as shown in Fig. 4. Use the gun cover ,
supplied, to help protect you hand and the gun
from overspray .
Fig. 4
3 in. (76 mm) square
cut out and finger
of glove cut of f


7. 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 .
8.
Flammable liquids in the spray area must be kept
in approved, grounded containers. Do not store
more than the quantity needed for one shift.
9. Fluid supply container: according to local code.
10. All solvent pails used when flushing, according to
local code. Use only metal pails, which are con -
ductive. Do not place the pail on a non–conductive
surface, such as paper or cardboard, which inter -
rupts the grounding continuity .

 
System Component Information
I. How to use the electrostatic air
spray gun (Fig. 5)
The air hose supplies air to the spray gun. Part of the
air operates the turbine and the rest of it atomizes the
fluid being sprayed. The turbine generates power
which is converted by the power cartridge to supply
high voltage to the gun’ s ionizing electrode.
The pump supplies fluid to the hose and gun, where
the fluid is electrostatically charged as it passes the
electrode. The charged fluid is attracted to the
grounded workpiece.
1. This gun has a dual triggering action. When you
squeeze the trigger , the first action is to open the
air . The second action, fully triggering the gun,
opens the fluid. Some startup procedures may
require that you trigger only the air .
2.
Loosen the air cap retaining ring (G) and rotate the
air horns to obtain the desired spray position.
T ighten the retaining ring snugly , but do not over -
tighten. If the horns of the air cap are vertical, the
spray pattern will be horizontal. If the horns are
horizontal, the spray pattern will be vertical. See
Fig. 6.
3. See the gun instruction manual, 307–912, for
detailed information, including troubleshooting,
cleaning, and repair .
CAUTION
Always hang the gun with its nozzle pointing down to
prevent solvent from running to the gun air pas -
sages. Solvent in the gun air passages can cause
poor atomization and excessive current demands
and damage the gun.
II. How to use the recirculation feature
(Fig. 7)
The recirculation tube (37) returns unused fluid to the
fluid container, ensuring an even flow at the gun.
Recirculation also provides gentle fluid agitation.
1. T o recirculate fluid, open the recirculating valve
(35).
2. T
o stop recirculation, close the valve (valve handle
at a right angle to the body of the valve). See Fig.
7.
3.
For gentle fluid agitation while spraying, open the
recirculation valve partially , but maintain the pump
cycle rate specified in Startup.
Fig. 5
IO
E
S
KEY
AES indicator light
B ES On–Of f lever
I is ON and 0 is OFF
C Fan air control valve
D Electrode
E
Air cap
A
B
C
DE
F
Fig. 6
Air cap horns shown horizontal
which produces a vertical
spray pattern
Air cap horns shown vertical
which produces a horizontal
spray pattern
Fig. 7
37
35
Shown
in open position



System Component Information
III. How to adjust the air and fluid
regulators (Fig. 8)
1. Always open air and fluid regulators slowly to
prevent surging during startup.
2. The fluid regulator (6) controls fluid from the pump
to the gun. For an accurate setting, adjust the fluid
regulator only when the gun is triggered and fluid is
flowing through the regulator . Be sure the jam nut
(H) under the T–handle does not interfere with
your adjustments. T ighten the jam nut to lock in
the setting, if desired.
3. T o open the fluid regulator , which allows fluid to
flow, turn the T -hand IN (clockwise).
4. T o close the fluid regulator , which restricts or shuts
of f the fluid flow , turn the T -handle OUT (counter -
clockwise).
5.
As you look at the system in Fig. 8 the air regulator
(5a) on the left of the pump controls air to the
pump and the regulator (5b) on the right controls
the air to the gun.
6. T o open the air regulator , pull out the adjusting
knob. T urn the knob IN (clockwise) to open and
turn the knob fully OUT (counterclockwise) to
close. Push the adjusting knob in to lock the
setting, if desired.
Fig. 8
6H
5a
5b
03994

 
Operation
I. Pressure relief procedure
The system remains pressurized until pressure is
manually relieved. To reduce the risk of serious
injury from pressurized fluid, accidental spray from
the gun or splashing of any fluid, follow this proce -
dure whenever you:
 are instructed to relieve pressure;
 stop spraying;
 check or service any system equipment;
 install, clean or change spray nozzles.
WARNING
1. Be sure the pump air regulator (5a) is still open.
Close the master air valve (A) to relieve pump air
pressure.
2. T
urn the ES On/Of f valve lever to OFF .
3. T
rigger the spray gun to relieve fluid pressure.
4. Open the fluid recirculating valve (35) to relieve all
fluid pressure.
II. Flush the pump before the first use
Flush with a solvent compatible to your fluid. Consult
the fluid manufacturer ’ s literature for recommenda -
tions. See Flushing on page 12.
III. Prime the system (Fig. 9)
1. Place the pump on a grounded metal pail of pre -
pared fluid. T ighten the thumbscrews lightly .
2.
Close the gun air regulator (5b) and the fluid
regulator (6).
3.
Open the recirculating valve (35).
4. Connect the air line (C) to the pump.
5. Open the master air valves (A).
6. T rigger the gun into a waste pail to release any
trapped pressure.
7. Slowly raise the pump air regulator (5a) pressure
to 20–30 psi (140–210 kPa, 1.4–2.1 bar). The
pump will cycle quickly until it is primed. When it is
primed, close the recirculating valve (35); the
pump will stall against pressure. If not, reopen the
recirculating valve for 30 seconds and then close.
Now set the pump air pressure to 40 psi (280 kPa,
2.8 bar).
8.
Hold the gun against and aimed into a grounded
metal waste pail. Trigger the gun and slowly open
the fluid regulator (6). The gun will emit air until the
fluid arrives. When fluid flows freely , release the
gun trigger .
Fig. 9
A
C
10 6
04001
5b
5a
KEY
A Bleed-Type
master air valve
C Air supply line
5a Pump air regulator
5b Gun air regulator
6 Fluid regulator
10 1/4” female quick disconnect coupler
35 Recirculating ball valve
14 Air cap
35 Recirculation ball valve
35

308-45210
Operation
IV. Set the fluid and air pressure
1. With the system primed and the gun regulator
closed, trigger the gun and adjust the pump air
pressure regulator (5a) to 60 psi (420 kPa, 4.2
bar).
2.
With the air cap removed, trigger the gun into a
grounded metal waste pail and set the fluid pres -
sure regulator (6). Use the fluid pressure setting
provided by your fluid supplier , if available. Other -
wise use the following instructions to determine the
fluid pressure.
T o determine the fluid pressure setting, hold the
gun parallel to the floor . (Be sure to catch the fluid
in a container). With the gun air pressure turned
OFF , trigger the gun. Adjust the fluid pressure
regulator (6) until the straight fluid stream is within
the range indicated for the viscosity of your fluid
before it drop of f. See Fig. 10. Make note of this
pressure on the fluid gauge; it is your optimal fluid
pressure setting.
3. Release the gun trigger . Install the air cap.
Fluid droop:
straight
stream
before fluid
drops of f
Fig. 10
Fluid V iscosity Fluid Droop
Measured with #2 Zahn cup
Light (18–25 seconds) 8–10” (200–250 mm)
Medium (25–40 seconds) 6–8” (150–200 mm)
Heavy (40–60 seconds) 4–6” (100–150 mm)
1
03998
1
1
4. Partially trigger the gun so only air is emitted. Set
the gun air regulator (5b) pressure to 70 psi (490
kPa, 4.9 bar).
5. Spray a stationary test pattern on scrap paper .
Hold the gun 10–12 in. (250–300 mm) from the
paper and spray for 2 or 3 seconds. If the spray
pattern is poorly atomized, the air and / or fluid
pressures may need adjustment.
If the spray pattern atomization is not fine enough,
increase the gun air pressure. If the spray pattern
atomization is too fine, decrease the gun air pres -
sure. If the air atomization is still not good enough,
try lowering the fluid pressure in increments of 2 or
3 psi to achieve the desired finish quality .
NOTE: For the most ef ficient paint usage, use the
lowest air pressure needed to obtain a good finish.
Higher air pressures create more overspray and use
more fluid.
Fig. 11
IO
E
S
KEY
AES indicator light
B ES On–Of f lever
I is ON and 0 is OFF
C Fan control valve
A
B
C
6. Turn the ES On/Of f lever (B) to ON (I position).
See Fig. 1 1.
NOTE: When spraying, the ES indicator light (A) will
glow , indicating the electrostatic charge. See Fig. 1 1.