Craftsman 921.166420 User Manual [en, es]

Owner’s Manual

AIR COMPRESSOR
20-gallon

1.5 HP
Oil-Free, Direct Drive

Model No. 921.166420

CAUTION:
Before using this product,
read this manual and follow
all its Safety Rules and
Operating Instructions.

Sears, Roebuck and Co., Hoffman Estates, IL 60179 U.S.A.

www.sears.com

11/14/2008

Part No. El 03645

Safety Instructions
Installation & Operation
Maintenance & Storage
Troubleshooting Guide
Parts List
Español, p. 11

Table of Contents

Page

Warranty....................................................................................................................................See Below

Safety Symbols............................................................................................................................... 1

Important Safety Instructions & Guidelines

Specifications................................................................................................................................... 2

Glossary........................................................................................................................................... 2

Duty Cycle........................................................................................................................................ 2

Parts & Features.............................................................................................................................. 3

Installation & Assembly................................................................................................................... 4

Operating Procedures...................................................................................................................... 5

Maintenance.................................................................................................................................... 6

Storage ............................................................................................................................................ 6

Troubleshooting Guide..................................................................................................................... 7

....................................................................................

1

Exploded View................................................................................................................................. 8

Parts List.......................................................................................................................................... 9

Español ........................................................................................................................................ 11

ONE YEAR FULL WARRANTY ON CRAFTSMAN AIR COMPRESSOR

If this Craftsman Air Compressor fails due to manufacturer’s defects in material or workmanship
within one year of the date of purchase, RETURN IT TO THE NEAREST SEARS STORE OR
SERVICE CENTER IN THE UNITED STATES and it will be replaced or repaired (at our option),
free of charge.

If this Air Compressor is used for commercial or rental purposes, this warranty applies for only 90
days from the date of purchase. This warranty gives you specific legal rights and you may also
have other rights which vary from state to state.

Sears, Roebuck and Co., Hoffman Estates, IL 60179

Safety Symbols

The information listed below should be read and understood by the operator. This information is given to protect the

user while operating and storing the air compressor. We utilize the symbols below to allow the reader to recognize important
information about their safety.

DANGER

Indicates an imminently hazardous situation which, if not

avoided, will result in death or serious injury.

A WARNING

Indicates a potentially hazardous situation which, if not

avoided, could result in death or serious injury

Indicates a potentially hazardous situation which, if not

avoided, may result in minor or moderate injury.

When used without the safety alert symbol indicates a
potentially hazardous situation which, if not avoided, may
result in property damage.

A CAUTION

CAUTION

Important Safety Instructions and Guidelines

• Save all instructions

A WARNING

Improper operation or maintenance of this product could result in serious injury and/or property damage. Read and
understand all of the warnings and safety instructions provided before using this equipment.

The air compressor should be operated on a dedicated 15 amp circuit. If the circuit does
not have 15 free amps available, a larger circuit must be used. Always use more air

CAUTION

hose before utilizing extension cords. All extension cords used must be 12 gauge with a
maximum length of 25 ft. The circuit fuse type must be a time delay. Low voltage could
cause damage to the motor.

Risk of Moving Parts

Risk of Burns

Risk of Falling

Risk from Flying Objects

If the air compressor is in operation, all guards and covers should be attached or
installed correctly. If any guard or cover has been damaged, do not operate the
equipment until the proper personnel has correctly repaired the equipment. The power
cord should be free of any moving parts, twisting and/or crimping while in use and while
in storage.

There are surfaces on your air compressor that while in operation and thereafter can
cause serious burns if touched. The equipment should be allowed time to cool before
any maintenance is attempted. Items such as the compressor pump and the outlet tube
are normally hot during and after operation.

Operation of the air compressor should always be in a position that is stable. Never use
the air compressor on a rooftop or elevated position that could allow the unit to fall or
be tipped over. Use additional air hose for elevated jobs.

Always wear ANSI Z87.1 approved safety glasses with side shields when the air
compressor is in use. Turn off the air compressor and drain the air tank before
performing any type of maintenance or disassembly of the hoses or fittings. Never point
any nozzle or sprayer toward any part of the body or at other people or animals.

Important Safety Instructions & Guidelines

Risk of Breathing

Risk of

Electrical Shock

Risk of

Explosion or Fire

Risk of Bursting

Avoid using the air compressor in confined areas. Always have adequate space
(12 inches) on all sides of the air compressor. Also keep children, pets, and others out of
the area of operation. This air compressor does not provide breathable air for anyone or
any auxiliary breathing device. Spraying material will always need to be in another area
away from the air compressor to not allow intake air to damage the air compressor filter.

Never utilize the air compressor in the rain or wet conditions. Any electrical issues or
repairs should be performed by authorized personnel such as an electrician and should
comply with all national and local electrical codes. The air compressor should also have
the proper three prong grounding plug, correct voltage, and adequate fuse protection.

Never operate the compressor near combustible materials, gasoline or solvent vapors.

If spraying flammable materials, locate the air compressor at least 20 feet away from the
spray area. Never operate the air compressor indoors or in a confined area.

Always drain the air compressor tank daily or after each use. If the tank develops a leak,
then replace the air compressor. Never use the air compressor after a leak has been
found or try to make any modifications to the tank. Never modify the air compressor’s
factory settings which control the tank pressure or any other function.

Specifications

Pump

.....................................................

Motor.............................................................................1.5 HP

Bore.................................................................................2.28"

Stroke..............................................................................0.87"

Voltage Single Phase................................................120 VAC

Oil-Free Direct Drive

Minimum Circuit Requirement
Air Tank Capacity

Cut-in Pressure............................................................120 PSI

Cut-out Pressure

SCFM @ 90 PSI..................................................................3.8

SCFM @ 40 PSI..................................................................5.1

...................................................

.........................................................

................................

Glossary

CFM: Cubic feet per minute.
SCFM: Standard cubic feet per minute; a unit of measure

for air delivery.

PSIG: Pounds per square inch gauge; a unit of measure

for pressure.

ASME: American Society of Mechanical Engineers.
California Code: Unit may comply with California Code

462 (I) (2)/ (M) (2).

Cut-In Pressure: The air compressor will automatically

start to refill the tank when the pressure drops
below the prescribed minimum.

Cut-Out Pressure: The point at which the motor stops

when the tank has reached maximum air
pressure.

Code Certification: Products that bear one or more of

the following marks: UL, ULc, ETL, CSA, have
been evaluated by CSHA-certified independent
safety laboratories and meet the applicable
Underwriters Laboratories Standards for Safety.

Duty Cycle

This is a 50% duty cycle air compressor. Do not run the air compressor more than 30 minutes of one hour. Doing so
could damage the air compressor.

15.0 Amps
20 Gallons

150 PSI

Parts & Features

See figures below for reference

Regulator

The air pressure coming from the air tank is
controlled by the regulator. To increase the pressure
turn the knob clockwise and to decrease the

pressure turn the knob counterclockwise.

Regulator Gauge

Indicates the outgoing air pressure to the tool and
is controlled by the regulator.

V_

Tank Pressure Gauge

Indicates the reserve air
pressure in the tank.

Air Intake Filter

Provides clean air to the pump and must
always be kept free of debris. Check on a
daily basis or before each use.

Pressure Switch

This controls the power to the motor and also
the cut-in/cut-out pressure settings. This
switch serves as the Auto-On/Off positions
for the unit.

Tank Safety Valve

Used to allow excess tank pressure to escape into
the atmosphere. This valve should only open when
the tank pressure is above the maximum rated

pressure.

Pressure Relief Valve

The pressure relief valve located on the side of the

pressure switch, is designed to automatically
release compressed air when the air compressor
reaches cut-out pressure. The released air should
only escape momentarily and the valve should
then close.

V.

Check Valve

When the pump is not in operation the valve
closes to retain air pressure inside the tank. An

internal component.

V.

Installation & Assembly

A WARNING

The air compressor should be turned off, unplugged from
the power source, the air bled from the tank and the unit
allowed time to cool before any maintenance is performed.

Personal injuries could occur from moving parts, electrical
sources, compressed air or hot surfaces. The quick connect
assembly must be attached before use. Failure to assemble
correctly could result in leaks and possible injury. If unsure
of assembly instructions or you experience difficulty in the
assembly please call your local service department for
further information.

Getting Started - Location of the Air Compressor

The air compressor should always be located in a clean,
dry and well ventilated environment. The unit should have
at minimum, 12 inches of space on each side. The air filter
intake should be free of any debris or obstructions.
Check the air filter on a daily basis to make sure it is clean
and in working order.

A WARNING

Risk Of Fire Or Explosion

This product incorporates snap action switch contacts and
a universal electric motor which tend to produce arcs and
sparking and therefore should not be exposed to flammable
liquids or vapors. This product is not intended for installation
or use in a commercial garage or shop environment.

A WARNING

Grounding Instructions

This product should be grounded. In the event of an electrical
short circuit, grounding reduces the risk of electric shock by
providing an escape wire for the electric current.
This product is equipped with a cord having a grounding
wire with an appropriate grounding plug. (See the figure
below.) The plug must be plugged into an outlet that is
properly installed and grounded in accordance with all local
codes and ordinances. Check with a qualified electrician or
service personnel if these instructions are not completely
understood or if in doubt as to whether the tool is properly
grounded.

Improper installation of the grounding plug will result in a
risk of electric shock. If repair or replacement of the cord
or plug is necessary, do not connect the grounding wire to
either flat blade terminal. The wire with insulation having an
outer surface that is green with or without yellow stripes is
the grounding wire. Check with a qualified electrician or
serviceman if the grounding instructions are not completely
understood, or if in doubt as to whether the product is
properly grounded. Do not modify the plug provided.

If it will not fit the outlet, have the proper outlet installed
by a qualified electrician.

This product is for use on a circuit having a nominal rating
of 120 volts and is factory-equipped with a specific electric
cord and plug to permit connection to a proper electric
circuit. Make sure the product is connected to an outlet
having the same configuration as the plug. An adapter
should not be used with this product. If the product must
be reconnected for use on a different type of electric circuit,
qualified service personnel should make the reconnection.

Extension Cords

Use only a 3-wire extension cord that has a 3-blade
grounding plug and a 3-slot receptacle that will accept the
plug on the product. Make sure your extension cord is in
good condition. When using an extension cord, be sure to
use one heavy enough to carry the current your product will
draw. Cords must not exceed 25 feet and No. 12 AWG size
must be used. An undersized cord will cause a drop in line
voltage resulting in loss of power and overheating.

Break In Procedures

No break in procedure is required by the user.
This product is factory tested to ensure proper operation and
performance.

Plug

Grounding Pin

Grounded

Outiet

Operating Procedures

Daily Start-Up Procedures

1. Set the Auto-On/Off switch to the Off position.

2. Inspect the air compressor, air hose, and any
accessories/tools being used for damage or obstruction.

If any of these mentioned items are in need of repair/
replacement, contact your local authorized dealer before
use.

3. Close the drain valve.

4. Connect the air hose to the quick connect socket on
the regulator assembly by inserting the quick connect
plug on the air hose into the quick connect socket. The
quick connect socket collar will snap forward and lock
the plug into place providing an air tight seal between
the socket and plug. To release the air hose push the
collar back on the quick connect socket.

5. Plug the power cord into the proper receptacle.

Turn the Auto-On/Off switch to the On-Auto position and

the compressor will start and build air pressure in the
tank to cut-out pressure and then shut off automatically.
Adjust the regulator to a PSI setting that is needed for
your application and be sure it is within the safety
standards required to perform the task. If using a
pneumatic tool, the manufacturer should have
recommendations in the manual for that particular
tool on operating PSI settings.
The air compressor is now ready for use. The following
inflation and cleaning accessories packaged with this
unit should only be operated at maximum pressure
of 90PSI: Blow gun, adapter and inflation needle.

3. Set the outlet pressure to zero on the regulator.

4. Remove any air tools or accessories.

5. Open the drain valve allowing air to bleed from the
tank. After all of the air has bled from the tank, close
the drain valve to prevent debris buildup in the valve.

Drain the tank in a suitable location; condensation will be
present in most cases of draining.

A WARNING

Water that remains in the tank during storage will corrode
and weaken the air tank which could cause the tank to
rupture. To avoid serious injury, be sure to drain the tank
after each use or daily.

Maintenance

NOTE: Any service procedure not covered in the

maintenance schedule should be performed by qualified
service personnel.

A WARNING

The air compressor should be turned off, unplugged from
the power source, air bled from the tank and allowed
time to cool before any maintenance is performed.

A WARNING

Do not attempt to remove or adjust the safety valve.

Check the safety valve by performing these three steps:

1. Plug the compressor in and run until shut-off pressure
is reached.

2. Wearing safety glasses, pull out on the safety valve ring
to release pressure from the tank.

3. The safety valve should close automatically at
approximately at 40-50 PSI. If the safety valve does not
allow air to be released when you pull out on the ring, or
does not close automatically, it must be replaced.

Maintenance Schedule

Items to Check/Change

Check Tank Safety Valve X
Overall Unit Visual Check X
Drain Tank X

Check Power Cord for Damage

Before each use

or daily

X

A CAUTION

To ensure efficient operation and longer life of the air
compressor unit, a routine maintenance schedule should
be followed. The following schedule is geared toward a
consumer whose compressor is used in a normal working
environment on a daily basis.

A CAUTION

This compressor is equipped with an automatic reset
thermal overload protector which will shut off motor if it
becomes overheated. If the thermal overload protector is
actuated, the motor must be allowed to cool down before
start-up is possible.

Storage

For storing the air compressor, be sure to do the following:

1. Turn the unit off and unplug the power cord from the
receptacle.

2. Remove all air hoses, accessories, and air tools from
the air compressor.

3. Perform the daily maintenance schedule.

NOTE: The motor will automatically restart without warn

ing if the unit is left plugged in to an outlet with the Auto­On/Off switch in the on position

4. Open the drain valve to bleed all air from the tank.

5. Close the drain valve.

6. Store the air compressor in a clean and dry location.