Grizzly H3372 User manual

COPYRIGHT © APRIL, 2003 BY GRIZZLY INDUSTRIAL, INC.
WARNING: NO PORTION OF THIS MANUAL MAY BE REPRODUCED IN ANY SHAPE
OR FORM WITHOUT THE WRITTEN APPROVAL OF GRIZZLY INDUSTRIAL, INC.
PRINTED IN CHINA
ONLINE MANUAL DISCLAIMER
THE INFORMATION IN THIS MANUAL REPRESENTS THE CONFIGURATION OF THE MACHINE
AS IT IS CURRENTLY BEING SHIPPED. THE MACHINE CONFIGURATION CAN CHANGE AS
PRODUCT IMPROVEMENTS ARE INCORPORATED. IF YOU OWN AN EARLIER VERSION OF
THE MACHINE, THIS MANUAL MAY NOT EXACTLY DEPICT YOUR MACHINE . CONTACT CUS-
TOMER SERVICE IF YOU HAVE ANY QUESTIONS ABOUT DIFFERENCES. PREVIOUS VER-
SIONS ARE NOT AVAILABLE ONLINE.
3 HP AIR COMPRESSOR
MODEL H3372
INSTRUCTION MANUAL

WARNING
Some dust created by power sanding, sawing, grind-
ing, drilling, and other construction activities contains
chemicals known to the State of California to cause
cancer, birth defects or other reproductive harm.
Some examples of these chemicals are:
• Lead from lead-based paints.
• Crystalline silica from bricks, cement, and
other masonry products.
• Arsenic and chromium from chemically treated
lumber.
Your risk from these exposures varies, depending on
how often you do this type of work. To reduce your
exposure to these chemicals: work in a well ventilated
area, and work with approved safety equipment, such
as those dust masks that are specially designed to fil-
ter out microscopic particles.

H3372 3 HP Air Compressor
For Your Own Safety Read Instruction Manual
Before Operating This Equipment
Indicates an imminently hazardous situation which, if
not avoided, WILL result in death or serious injury.
Indicates a potentially hazardous situation which, if
not avoided, MAY result in minor or moderate injury. It
may also be used to alert against unsafe practices.
This symbol is used to alert the user to useful infor-
mation about proper operation of the equipment.
The purpose of safety symbols is to attract your attention to possible hazardous
conditions. This manual uses a series of symbols and signal words which are
intended to convey the level of importance of the safety messages. The progres-
sion of symbols is described below. Remember that safety messages by them-
selves do not eliminate danger and are not a substitute for proper accident pre-
vention measures.
NOTICE
Safety Instructions For Pneumatic Tools
1. KEEP ALL SAFETY DEVICES IN
PLACE and in working order.
2. REMOVE ADJUSTING KEYS AND
WRENCHES. Form a habit of
checking to see that keys and
adjusting wrenches are removed
from tool before operation.
3. KEEP WORK AREA CLEAN.
Cluttered areas and benches invite
accidents.
4. DO NOT USE IN DANGEROUS
ENVIRONMENT. DO NOT use
pneumatic tools in damp or wet
locations, or where any flammable
or noxious fumes may exist. Keep
work area well lighted.
SAFETY
5. KEEP CHILDREN AND VISITORS
AWAY. All children and visitors
should be kept at a safe distance
from work area.
6. MAKE WORKSHOP CHILD
PROOF with padlocks, master
switches, or by removing air hoses
from tools.
7. DO NOT FORCE TOOL. It will do
the job better and safer at the rate
for which it was designed.
8. USE THE RIGHT TOOL. DO NOT
force tool or attachment to do a job
for which it was not designed.
9. DO NOT USE UNDER THE INFLU-
ENCE OF DRUGS OR ALCOHOL.
Indicates a potentially hazardous situation which, if
not avoided, COULD result in death or serious injury.
-1-

H3372 3 HP Air Compressor
10. USE PROPER AIR HOSE for the
tool. Make sure your air hose is in
good condition and is long enough to
reach your work without stretching.
11. WEAR PROPER APPAREL. DO
NOT wear loose clothing, gloves,
neckties, rings, bracelets, or other
jewelry which may get caught in
moving parts. Non-slip footwear is
recommended. Wear a protective
hair covering to contain long hair.
12. ALWAYS USE SAFETY GLASSES.
Also use a face or dust mask if cut-
ting operation is dusty. Everyday
eyeglasses only have impact resis-
tant lenses, they are NOT safety
glasses.
13. WEAR APPROVED HEARING
PROTECTION.
14. SECURE WORK. Use clamps or a
vise to hold work when practical. It is
safer than using your hand and frees
both hands to operate tool.
15. DO NOT OVERREACH. Keep prop-
er footing and balance at all times.
16. MAINTAIN TOOLS WITH CARE.
Keep tools lubricated and clean for
best and safest performance. Follow
instructions for lubricating and
changing accessories.
17. REDUCE THE RISK OF UNINTEN-
TIONAL STARTING. DO NOT carry
tool with hand on trigger and always
disconnect from air when not in use.
Safety Instructions For Pneumatic Tools
18. DISCONNECT TOOLS before ser-
vicing and changing accessories.
19. USE THE RECOMMENDED
ACCESSORIES. Consult the
owner’s manual for recommended
accessories. The use of improper
accessories may cause risk of
injury.
20. CHECK DAMAGED PARTS.
Before further use of the tool, a
guard or other part that is damaged
should be carefully checked to
determine that it will operate prop-
erly and perform its intended func-
tion. Check for alignment of moving
parts, binding of moving parts,
breakage of parts, mounting, and
any other conditions that may affect
its operation. A guard or other part
that is damaged should be properly
repaired or replaced.
21. NEVER LEAVE UNATTENDED
TOOL CONNECTED TO AIR.
Disconnect the air hose and DO
NOT leave tool until it is relieved of
any built up pressure.
22. NEVER ALLOW UNTRAINED
USERS TO USE THIS TOOL
WHILE UNSUPERVISED.
23. IF YOU ARE UNSURE OF THE
INTENDED OPERATION, STOP
USING THE TOOL. Seek formal
training or research books or maga-
zines that specialize in pneumatic
tools.
-2-

H3372 3 HP Air Compressor
1. READ THIS ENTIRE MANUAL
BEFORE OPERATING THE
COMPRESSOR.
2. OPERATE THE COMPRESSOR IN
A WELL VENTILATED AREA free
of acids, vapor, explosive gases and
flammable or unstable materials.
3. DO NOT PULL ON THE GAUGES
OR REGULATORS TO MOVE THE
COMPRESSOR!
4. DO NOT USE THE COMPRESSOR
FOR FILLING BREATHING OR DIV-
ING APPARATUS. Compressed air
from this compressor cannot be used
for pharmaceutical, food or health
requirements without further treat-
ment.
5. NEVER TRANSPORT THE COM-
PRESSOR UNDER PRESSURE.
Always release the pressure in the
storage tanks before moving.
6. NEVER RUN THE COMPRESSOR
BEYOND THE ADVISED DUTY
CYCLE! The advised duty cycle is
described on page 7.
Additional Safety For
Air Compressors 7. DRAIN TANK DAILY OR AT THE
END OF EACH USE to avoid tank
corrosion and possible tank rupture.
8. AVOID TOUCHING THE TOP OF
THE MOTOR HOUSING, it will
become hot during operation.
9. MAKE SURE TO ADD OIL! Use
compressor oil or a non-detergent 30
weight oil.
10. NEVER LEAVE COMPRESSOR
TURNED ON WHEN NO ONE IS
AROUND! A leak could develop caus-
ing compressor to run continuously
causing overheating and possibly a
fire.
11. NEVER AIM THE AIR NOZZLE
DIRECTLY AT YOURSELF OR OTH-
ERS. Pressurized air can break or
bruise the skin.
12. NEVER LOAD YOUR COMPRES-
SOR PAST THE MAXIMUM PSI
RATING OF 115 PSI.
Operating this compressor can pro-
pel objects into the air, causing
immediate eye damage. To protect
yourself, always wear American
National Standards Institute (ANSI)
approved safety glasses or goggles
when operating this equipment.
-3-
Always be aware of the duty cycle
for your air compressor. Failure to
operate the air compressor proper-
ly could result in overheating and
motor seizure. There could also be
risk of fire hazard due to overheat-
ing. Be sure to use a compressor
capable of handling the air demand
of connected tools

H3372 3 HP Air Compressor-4-
INTRODUCTION AND SET UP
If you have any comments regarding this
manual, please write to us at the following
address:
Grizzly Industrial, Inc.
C/O Technical Documentation
P.O. Box 2069
Bellingham, WA 98227-2069
Most important, we stand behind our tools.
If you have any service questions or parts
requests, please call or write us at the
location listed below.
Grizzly Industrial, Inc.
1203 Lycoming Mall Circle
Muncy, PA 17756
Phone: [phone]
Fax: [phone]
E-Mail: [email protected]
Web Site: http://www.grizzly.com
We are proud to offer the Grizzly Model
H3372 3 HP Air Compressor. This model
is part of a growing Grizzly family of fine
power tools. When used according to the
guidelines set forth in this manual, you can
expect years of trouble-free, enjoyable
operation and proof of Grizzly’s commit-
ment to customer satisfaction.
The Model H3372 features a powerful
220V 3 HP motor, two cylinder aluminum
pump with cast iron cylinder liners, an
incredible 10.9 CFM@ 40 PSI, 9.1 CFM
@90 PSI, 11 gallon welded steel tank, and
a 115 PSI maximum working pressure.
The Model H3372 compressor fills its 11
gallon tank from 0 to 115 PSI in a little over
a minute!
We are pleased to provide this manual
with the Model H3372. It was written to
encourage safety considerations and
guide you through general operating pro-
cedures and maintenance. This manual
represents our effort to produce the best
documentation possible.
The specifications, details, and pho-
tographs in this manual represent the
Model H3372 as supplied when the manu-
al was prepared. However, owing to
Grizzly’s policy of continuous improve-
ment, changes may be made at any time
with no obligation on the part of Grizzly. Read the manual before assembly
and operation. Become familiar with
this tool, its safety instructions, and
its operation before beginning any
work. Serious personal injury may
result if safety or operational infor-
mation is not understood or followed.
Commentary

H3372 3 HP Air Compressor -5-
The Model H3372 represents a heavy
load at 142 pounds. Seek assistance
before moving.
This air compressor is shipped from the
manufacturer in a carefully packed carton.
If you discover the machine is damaged
after you have signed for delivery, and the
truck and driver are gone, you will need to
file a freight claim with the carrier. Save the
containers and all packing materials for
possible inspection by the carrier or its
agent. Without the packing materials, filing
a freight claim can be difficult. If you need
assistance determining whether you need
to file a freight claim, or with the procedure
to file one, please contact our Customer
Service at [phone].
When determining where to set up the
compressor in the shop, or when taking the
air compressor to a job site, the most
important consideration is access to an
adequate and properly fused power sup-
ply. Refer to Circuit Requirements for the
needs of your particular compressor.
Also, make sure the compressor is not
operating in an environment where there
are any explosive, flammable or caustic
fumes or gases. A clear and well ventilated
area is best for its safe operation.
Place the compressor on a solid and level
surface. Make sure that the hoses you
attach to your pneumatic device will be
unrestricted in movement and not subject
to being run over by vehicles or punctured
by any sharp objects in the area.
Since air compressors are often used for a
sustained period of time, sometimes in
restricted areas, it is also best to wear ear
protection to avoid long term exposure to
the sound of the electric motor and com-
pression pump.
Long term exposure to this machine
may cause hearing loss. Wear
approved hearing protection while
operating this machine to minimize
this risk!
Unpacking Site Placement
Do not place the compressor next to
any flammable liquids or gas! The
compressor cylinder head and feed
pipe can reach high temperatures and
could cause the flammable gas to
ignite. Keep work area clear from
flammable gas when using the com-
pressor.

H3372 3 HP Air Compressor-6-
CIRCUIT REQUIREMENTS
Wiring:
The Model H3372 3 HP Air Compressor is
wired for 220V operation.
Amperage Draw
The Model H3372 has a 3 HP motor and
draws the following amperage.
H3372 Motor.................................18 Amps
Circuit Breaker Requirements
Install your air compressor on a dedicated
circuit to reduce the possibility of overload-
ing the circuit and tripping the circuit break-
er. However, if an unusual load does not
exist, and the circuit breaker still trips, have
the circuit inspected by a qualified electri-
cian. Never use a larger circuit breaker
than stated below, or you will increase the
risk of fire.
Circuit Breaker...........20 Amp Double Pole
220V Operation
Extension Cords
In the event of an electrical short, ground-
ing reduces the risk of electric shock by
providing a path of least resistance to dis-
perse electric current. These machines are
equipped with power cords having an
equipment-grounding conductor. See
Figure 1. The outlet must be properly
installed and grounded in accordance with
all local codes and ordinances.
Grounding
Figure 1. Ground plug configuration.
If you find it necessary to use an extension
cord with your compressor, make sure the
cord is rated Standard Service (grade S) or
better. The extension cord must also con-
tain a ground wire and plug pin. Always
repair or replace extension cords when
they become worn or damaged.
Overheating, short circuit and fire
damage will result form inadequate
wiring. Follow the guidelines in this
section.
Potential for electrical shock haz-
ard, this equipment must be
grounded. Verify that any existing
electrical outlet and circuit you
use is actually grounded.

H3372 3 HP Air Compressor -7-
PREPARING FOR USE
Before using your Grizzly Air
Compressor, follow these steps :
1. Remove all packing materials and any
protective plastic bags, zip-tie labels
or tags from the compressor cylinder
head or oil plug.
2. Be sure the air filter is attached to the
cylinder head as shown in Figure 2.
Figure 3. Proper oil level.
4. Make sure the drain valve under the
air tank is closed.
3. ADD OIL TO THE CRANKCASE. Oil
has been supplied with your air com-
pressor. The oil level should be in the
center of the sight gauge shown in
Figure 3.
NOTICE
The machine should never be run
without a full oil reservoir. The oil
provides lubrication to the cylinder
rings which deliver the compressed
air. Severe damage to the internal
moving parts can occur if there is
not adequate oil flow. Check the oil
level frequently, and change the oil
on a regular schedule.
Figure 2. Air filter attached to
cylinder head.
Duty Cycle
The Model H3372 3 HP Air Compressor
should not be operated on more than a
50% duty cycle. This means an air com-
pressor that pumps air for over 30 minutes
in one hour is considered misuse. This
could mean that the air compressor is
undersized for the required air demand.
The maximum compressor pump time per
hour is 30 minutes.
Always be aware of the duty cycle for
your air compressor. Failure to oper-
ate the air compressor properly
could result in overheating and
motor seizure. There could also be
risk of fire hazard due to overheat-
ing. Be sure to use a compressor
capable of handling the air demand.

H3372 3 HP Air Compressor-8-
STARTING
To start the air compressor:
1. Make sure the compressor switch is
in the OFF position (knob with red
cap above pressure gauges shown
in Figure 4 pressed down) before
connecting the power supply.
Figure 4. ON/OFF button.
Check the pressure gauge to see that the
tank pressure climbs to approximately 100-
115 PSI or around 8 BAR, then automati-
cally turns off.
Note—If the compressor does not auto-
matically kick off, flip the ON/OFF switch to
OFF before pressure gets too high. See
the Pressure Regulator sub-section.
Operating this equipment has the
potential for flying debris to cause
eye injury. Always wear safety glass-
es or goggles when operating equip-
ment. Everyday glasses or reading
glasses only have impact resistant
lenses, they are not safety glasses.
Be certain the safety glasses you
wear meet the appropriate standards
of the American National Standards
Institute (ANSI).
2. Close the drain valve, shown in
Figure 5, so the tank can build up
pressure.
3. Double check the oil level to make
sure it is at the proper height.
4. Connect the compressor to the
power supply.
5. Pull the switch up to the ON position
to start compressor.
Figure 5. Drain valve location.

H3372 3 HP Air Compressor -9-
To control the air delivery to your tool:
1. Adjust the air control knob, shown in
Figure 7,to set the PSI that will be
delivered to your tool. Turn the knob
clockwise to increase the pressure
and counter-clockwise to decrease
the pressure.
Figure 7. Air control knob.
Figure 6. Pressure gauges.
The tank pressure is displayed on the left
pressure gauge, and the air to be delivered
to the tool is displayed on the right pres-
sure gauge shown in Figure 6.
AIR CONTROL
Delivered Pressure
Figure 8. Safety drain valve.
There are two ways to release air from the
compressor tank other than through your
regulator and the use of air tools:
—The drain valve.
—The safety drain valve.
To release air by using the drain valve,
simply turn the release nut to allow air to
flow out of the tank. The drain valve is
shown in Figure 5. The drain valve is also
used to drain condensation that builds up
in the tank.
The safety valve automatically releases
pressure if the tank reaches 130 PSI.
To manually release the air in the tank
by using the safety drain valve:
1. Locate the safety drain valve on the
tank. The drain valve is shown below
in Figure 8.
Air Release
2. Pull the metal ring on top of the safe-
ty valve to bleed pressure from the
tank. Note—The ring is preset to
release air if the tank exceeds its
maximum pressure of 130 PSI. DO
NOT try to adjust the safety valve!
Note—The air tool that you attach to the air
compressor should have a preferred PSI
operating level. Set the pressure to be
delivered to the tool according to this pre-
ferred level. Understand the duty cycle
of the air compressor that is described
on page 7.

H3372 3 HP Air Compressor-10-
The pressure regulator has been factory
set for the highest quality operating perfor-
mance.
The pressure regulator adjusts the desired
PSI range where the air compressor kicks
in and out to keep the tank pressurized for
the best operating performance.
Tank Pressure
Regulator
Figure 9. Pressure Regulator.
To adjust the pressure regulator:
1. Unplug the air compressor from
the power supply.
2. Make sure the compressor switch is in
the OFF position.
3. Drain the pressure from the tank.
4. Remove the black ON/OFF switch
cover by removing the screw which is
in the recess on the top of the cover.
Pull the black cover up and set it
aside.
5. Turn the pressure adjustment bolt
(Figure 9) a half turn clockwise to
increase the tank pressure and a half
turn counter-clockwise to decrease
the pressure.
6. Connect the compressor to the power
supply and start the compressor.
7.If the PSI level still needs adjustment
repeat steps 1 through 6.
8. Replace the cover when the proper
adjustments have been made.
NOTICE
The Model H3372 3 HP Air
Compressors have been factory set
to kick off at the proper PSI range.
Only attempt to adjust the pressure
regulator if your air compressor
does not reach or pressurizes
beyond the proper PSI level.

H3372 3 HP Air Compressor -11-
To connect air tools to your air com-
pressor:
1. Make sure the compressor model you
use has a sufficient cubic feet per
minute (CFM) output for the air tool
you plan to connect. (Most air tools
will have an air requirement stated in
terms of a specific CFM at a specific
pressure.)
2. The compressor should put out a
higher CFM than the tool requires.
—If you are connecting multiple tools
that will be used simultaneously, then
the CFM for each tool should be
added together and compared to the
compressor output value.
Consideration should also be given to the
type of usage. A nailer or staple gun uses
air in short bursts and it is easier for the
compressor to maintain pressure. A paint
sprayer or grinder tends to use a more
continuous stream of air as these tools are
run for longer time periods. It is always
better to oversize a compressor to allow
for variation in the type of usage and the
number of tools to be powered. Air tools
being operated with insufficient air volume
will not perform their function satisfactorily.
Figure 10. Quick connect couplers.
3. Connect the tool, using a good quality
air line with an adequate length to
reach from the compressor to the
point of use.
Note—Quick-connect couplers, shown in
Figure 10,are a good option for fast and
sure connection of tools and air hoses.
This accessory and many like it can be
found in the Grizzly Catalog.
CONNECTING TOOLS
Always disconnect air hose from
tools whenever not in use or while
servicing! During maintenance, a
tool connected to air may operate
accidentally, causing serious per-
sonal injury!
Make certain the air hose will not be placed
in a position where it can become con-
stricted or cut by a sharp object. Note—
Running over a hose with heavy vehicles
may not cause an immediate leak, but it
will shorten the life of the hose.
The Model H3372 3 HP Air
Compressors are specifically
designed for air tool operation. DO
NOT MODIFY OR USE THIS
MACHINE FOR ANY OTHER PUR-
POSE. Modifications or improper
use of this tool will void the warran-
ty. If you are confused about any
aspect of this machine, DO NOT use
it until you have answered all your
questions. Serious personal injury
may occur.

H3372 3 HP Air Compressor-12-
3.Clean off cylinder head cooling fins of
any dirt which might hamper air flow.
4. Check for worn or damaged cords
and plugs.
5. Check the air pressure in the tires
when transporting the air compressor.
6. Check for any other condition that
could hamper the safe operation of
this machine.
MAINTENANCE
Before Each Use
Regular periodic maintenance on your Air
Compressor will ensure its optimum perfor-
mance. Make a habit of inspecting the fol-
lowing items before each time you use the
air compressor.
Check the following items:
1. Check Oil Level! Use the sight gauge
on the bottom of the crankcase to
make sure the oil level is at the prop-
er height.
2. Drain the tanks of any condensation
by opening the drain valve on the bot-
tom of the tank. Note—Depending
upon the amount of use and the
weather conditions, a certain amount
of condensed water may be released.
For longevity of the compressor seals
and the air tools you connect, it is best
to keep the tanks free of water. The
tanks are best drained if the drain
valve is open when the system is
pressurized. Once water has stopped
coming out, you can close the drain
valve.
Always wear safety glasses and use
extreme caution when working
around compressed air. The force of
the air stream can cause small bits
of debris to become airborne and
cause potential injury to the eyes or
other parts of the body.

H3372 3 HP Air Compressor -13-
Changing V-belt
Make sure the V-belt is properly ten-
sioned. If the V-belt is too tight, the
motor could overheat and cause
machine damage or fire. If the V-belt
is too loose, the belt will slip on the
pulley and cause belt damage and
compressor inefficiency.
Figure 11. Belt Guard and
mounting bolts.
Figure 12. Mounting bolt locations.
Figure 13. V-belt deflection.
To change the V-belt drive on your air
compressor:
1. Remove the belt guard from the air
compressor shown in Figure 11. The
guard is attached to the compressor
frame by the two mounting bolts
shown in Figure 11.
2. Loosen the four nuts (one side shown
in Figure 12) that secure the motor to
the compressor frame so the motor
can slide towards crankcase, relieving
the tension on the V-belt.
3. Remove the V-belt from the motor pul-
ley and fly pulley.
4. Install the new V-belt.
5. Reposition the motor in its original
place so the belt is tensioned, and
secure the four mounting bolts loos-
ened in step 2.
6. A properly tensioned V-belt will have
about a 1⁄2inch deflection as shown in
Figure 13. Replace the belt
guard.
7. Replace belt gaurd.
1⁄2Inch of Deflection

H3372 3 HP Air Compressor-14-
If the compressor is used on a daily
basis, perform the following checks
each week:
•Rinse the air filter foam element in
water.
•Check for loose bolts or fittings.
Weekly
Like all power tools, there is danger
associated with operating this
equipment. Accidents are frequently
caused by lack of familiarity or fail-
ure to pay attention. Use this tool
with respect and caution to lessen
the possibility of operator injury. If
normal safety precautions are over-
looked or ignored, serious personal
injury many occur.
After First 50
Hours Of Use
After the first 50 working hours or 30
days, whichever comes first, perform
the following maintenance:
•Replace the oil in the motor with com-
pressor oil (use ISO 100 of SAE 30W
viscosity, non detergent type).
•Make sure that all the fittings are tight.
•Remove the air filter foam element
shown in Figure 14 and rinse it out
with water. Allow it to dry and re-
install.
Figure 14. Air filter foam element
•Blow out any accumulated dirt
between the cylinder cooling fins.
The Model H3372 3 HP Air
Compressors are specifically
designed for air tool operation. DO
NOT MODIFY AND/OR USE THIS
MACHINE FOR ANY OTHER PUR-
POSE. Modifications or improper
use of this tool will void the warran-
ty. If you are confused about any
aspect of this machine, DO NOT use
it until you have answered all your
questions. Serious personal injury
may occur.

H3372 3 HP Air Compressor -15-
After every 300 hours or 3 months of
regular operation, perform the following
maintenance items:
•Change the compressor motor oil.
Use compressor oil or a non-deter-
gent 30 weight oil.
•Rinse the air filter foam element in
water.
•Check for air leaks and correct as
needed.
•Clean the cylinder head fins for prop-
er cooling.
•Check for loose bolts or fittings.
When storing your air compressor fol-
low these guidelines:
1. Set the ON/OFF button to OFF.
2. Turn the regulator counter-clockwise
to set the delivery pressure to zero.
3. Disconnect air tools or accessories.
4. Pull the safety drain valve ring to
bleed excess pressure from tank. The
pressure gauge for the tank should
read 15-20 PSI.
5. Drain water from the tank by opening
the drain valve on the bottom of the
tank.
6. Close the drain valve when all the
water has been released.
7. Store the air compressor in its normal
operating position in a cool protected
area.
Every 300 Hours Storage
Like all power tools, there is danger
associated with operating this
equipment. Accidents are frequently
caused by lack of familiarity or fail-
ure to pay attention. Use this
machine with respect and caution to
lessen the possibility of operator
injury. If normal safety precautions
are overlooked or ignored, serious
personal injury many occur.
NOTICE
Water will condense in the air com-
pressor tank. Water left in the tank
can cause the tank to weaken and
corrode, increasing the risk of tank
rupture.

-16-H3372 3 HP Air Compressor
TROUBLESHOOTING
Pump motor
will not start.
Pump motor
starts; but
fuses blow or
circuit break-
ers trip.
Low pressure
at the tool.
Low pressure
at the tanks.
Compressor
knocking.
1. Check power line for proper voltage.
2. Inspect all lead connections on motor,
switch and cord for loose or open connec-
tions.
3. Motor will not start if tank pressure is too
high.
4. Thermal overload switch has tripped, wait
for motor to cool, then reset switch by
pressing red button.
1. Inspect cord or plug for damaged insula-
tion and shorted wires.
2. Inspect all connections on motor for loose
or shorted terminals or worn insulation.
3. Install correct fuses or circuit breakers.
1. Check air hoses and all connections for
leaks.
2. Check pressure in line with known good
gauge.
3. Adjust pressure regulator, if no improve-
ment inspect regulator for leaks or
replacement.
4. Install a shorter hose.
1. Check air tanks, pipes and all connections
for leaks.
2. Close drain valve.
3. Replace safety valve.
4. Inspect and clean air filter.
5. Check gaskets on cylinder head assem-
bly, repair or replace as needed.
6. Inspect and replace pump piston rings.
1. Check oil level and add oil.
2. Inspect and clean air filter.
3. Inspect and repair piston and connecting
rod.
PROBLEM CAUSE ACTION
1. Low voltage.
2. Open circuit in
motor, switch or
cord.
3. Tank already pres-
surized.
4. Thermal overload
switch.
1. Short circuit in line
cord or plug.
2. Short circuit in motor
or loose connec-
tions.
3. Incorrect fuses or
circuit breakers in
power line.
1. Air leaks in flexible
hoses.
2. Pressure gauge bad.
3. Pressure regulator
bad.
4. Hose is too long.
1. Air leaks in tanks or
delivery pipes.
2. Drain valve open.
3. Safety valve releas-
ing below 125 PSI.
4. Air filter clogged.
5. Gaskets leaking.
6. Worn rings.
1. Improper oil level.
2. Air filter clogged.
3. Piston assembly
loose.

H3372 3 HP Air Compressor -17-
Motor runs
hot.
Pressure relief
valve stays
open and
motor won’t
stop running.
Air leaks from
pressure
switch.
Air is dirty or
has excessive
moisture.
1. Clean cylinder fins and motor area.
2. Inspect and clean air filter.
3. Do not allow the compressor to run over
its recommended duty cycle.
1. Turn compressor off, unplug from power
supply, drain tank. DO NOT USE until
switch is repaired or replaced.
2. Relief valve is relieving pressure too
early, test pressure relief and repair or
replace.
1. Clean dirt or debris from rubber mem-
brane of check valve after removing top
nut.
2. Repair or replace pressure switch.
1. Open drain cocks on both tanks and make
certain all condensation water is drained
out.
2. Remove delivery pipes, clean out and
replace.
PROBLEM CAUSE ACTION
1. Cooling fins dirty.
2. Air filter clogged.
3. Compressor is
exceeding its duty-
cycle.
1. Faulty pressure
switch, unit is trying
to overpressure the
tank.
2. Faulty pressure
relief valve.
1. Faulty check valves.
2. faulty pressure
switch.
1. Tank is not drained.
2. Delivery pipes are
dirty.

H3372 3 HP Air Compressor-18-
90
93
95
96
82
89
70
65
71
62
81
68
69
67
42
41
79
76
50
47
48
10
43
65
72
74
73
86
83
84
55
45
63
64
17
65
54
53
52
58
16
15
9
813 14
39
12
56
60
59
28
29
80
38
27
3
24
25
26
30 4
2
11
7
6
5
18
34
31
32
33 22
20
19
37
21
23
35
36
1
9
29
40
44
46
49
51
57
61
63
63
64
64
65
66
66
75
77
78
63
63
85
87
88
91
92
94
Model H3372 3 HP Air Compressor