Motomaster 058-7949-6 User manual

Air Compressor
5-gallon
058-7949-6
Owner’s Manual
Parts Missing or Damaged? Questions? Toll-Free Help Line – 1-888-942-MOTO (1-888-942-6686)
IMPORTANT: Ensure that all users have read all safety rules and operating instructions
carefully before using this product. Keep this Owner’s Manual in a safe place for future
reference.

TABLE OF CONTENTS
TECHNICAL SPECIFICATIONS …………………………..…………………………………………………………….2
SAFETY GUIDELINES …………………………………………………………………………………………….3
KNOW YOUR AIR COMPRESSOR ………………………………………………………………………………4-5
BEFORE YOU START:
GENERAL PERFORMANCE & USAGE GUIDELINES……………….………………………………………….…6
ASSEMBLYING INSTRUCTIONS………………………..………………………………………………………….7
BREAK-IN OF THE PUMP……………………………………….………………………………………….…………8
OPERATING INSTRUCTIONS:
STARTUP………………………………………………………………………………………………………….9
SHUTDOWN ……………………………………………………………………………………………………...9
MAINTENANCE …………………………………………………………………………………………………….10
TROUBLESHOOTING CHART …………………………………….………………………………………….……11-12
PARTS SCHEMATIC ………………………………………………………………………………….……..……13
PARTS LIST ……………………………………………...………………………………………………………...……..13
WARRANTY …………………………………………………………………………………………………...…..14
SPECIFICATIONS
Product number 058-7949-6
Peak horsepower 2
Tank size 2 1/2 gallons (x2)
Air delivery (SCFM) @ 40 PSI 5.1
Air delivery (SCFM) @ 90 PSI 4.1
Cut-in pressure (PSI) 95
Maximum pressure (PSI) 125
Pumpdesign Cast-Ironcylinder,
oil-lubricated, direct drive,
single phase
Motor Induction - 3400 RPM
Power 120 V, 60 Hz, 15 A
Weight 55 lb (25 kg)
Power cord SJT 14 AWG / 78” (1.98 m)
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Safety Guidelines
This manual contains information that relates to PROTECTING PERSONAL SAFETY and PREVENTING
EQUIPMENT PROBLEMS. It is very important to read this manual carefully and understand it thoroughly
before using the air compressor. The symbols listed below are used to indicate this information.
POTENTIALHAZARDTHATWILL RESULT IN SERIOUS INJURY OR LOSS OF LIFE
POTENTIAL HAZARD THAT COULD RESULT IN SERIOUS INJURY OR LOSS OF LIFE
POTENTIAL HAZARD THAT MAYRESULT IN MODERATE INJURY OR DAMAGE TO EQUIPMENT
1) RISK OF EXPLOSION OR FIRE. Do not spray flammable liquids in a confined area. It is normal for the motor
and pressure switch to produce sparks while operating. If sparks come into contact with vapours from gasoline
or other solvents, they may ignite and cause a fire or an explosion. Do not smoke while spraying. Do not spray
where sparks or flames are present. Keep the air compressor as far away from the spraying area as possible.
Always operate the air compressor in a well-ventilated area.
2) RISK OF ELECTRIC SHOCK. All wiring must be installed by a licensed electrician, in accordance with all
local and national codes. In order to avoid electric shock, do not use an electric air compressor outdoors
when it is raining or on a wet surface.
3) RISK OF BURSTING. Rust can weaken the tank. Drain the condensed water from the tank after each use in
order to reduce rusting. Welding or making modifications to the air tank can severely diminish the strength of
the tank, and could cause an extremely hazardous condition. Do not weld, drill, or modify the air tank. If a
leak is detected in the tank, replace the tank immediately.
4) RISK OF INJURY. Be sure to shut off the air compressor; unplug it from the outlet. Bleed all pressure from
the system before servicing the air compressor or when it is not in use. Do not use the air compressor with
the shrouds removed. Contact with moving parts could cause serious injury.
5) RISK OF BURSTING. Check the maximum pressure rating in the manual or the serial number label. The
compressor outlet pressure must be regulated so that it does not exceed the maximum pressure rating.
Relieve all pressure in the hose before removing or attaching accessories.
6) RISK OF BURSTING. Do not adjust the pressure switch or relief valve for any reason. They have been
preset at the factory for this air compressor’s maximum pressure. Tampering with the pressure switch or the
relief valve may cause personal injury or property damage.
7) RISK OF BURNS. The pump and the manifold generate high temperatures. In order to avoid burns or other
injuries, do not touch the pump, the manifold, or the transfer tube while the air compressor is running. Allow the
parts to cool down before handling or servicing. Keep children away from the air compressor at all times.
8) RISK TO BREATHING. Carefully read all labels when you are spraying paints or toxic materials, and follow
the safety instructions. Use a respirator mask if there is a chance of inhaling anything that is being sprayed.
Do not directly inhale the compressed air produced by an air compressor.
9) RISK OF EYE INJURY. Wear ANSI Z87.1 approved safety goggles when using an air compressor. Do not
point any nozzle or sprayer toward a person or any part of the body. Serious injury may occur if the spray
penetrates the skin.
1. Pull the pressure relief valve ring every day in order to ensure that the valve is functioning properly.
2. The air compressor must be located in a well-ventilated area for cooling, and must be a minimum of
12” (31 cm) away from the nearest wall.
3. Protect the air hose and the power cord from damage and puncture. Inspect them for weak or worn spots
every week, and replace them if necessary.
4. Always wear hearing protection when using an air compressor. Failure to do so may result in hearing loss.
5. Do not operate the compressor if it is not in a stable position.
6. Do not operate the air compressor on a rooftop or an elevated position that could allow the unit to fall or be
tipped over.
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KNOW YOUR AIR COMPRESSOR
A--------ELECTRIC MOTOR (not visible)
B--------AIR COMPRESSOR PUMP
C--------PRESSURE SWITCH
D--------PRESSURE RELIEF VALVE
E--------AIR PRESSURE REGULATOR
F--------TANK PRESSURE GAUGE
G--------REGULATED PRESSURE GAUGE
H--------AIR LINE OUTLET
I---------AIR TANK DRAIN VALVE
J---------AIR TANK
K--------POWER CORD
Standard Equipment
25’ recoil hose with 1/4” NPT connector and quick connector
B
A
C
D E
F G
H
I
J
K D
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KNOW YOUR AIR COMPRESSOR
A. ELECTRIC MOTOR: The motor is used to power the pump. It has a thermal overload protector and an
automatic reset. If the motor overheats for any reason, the thermal overload protector will shut it down to
prevent the motor from being damaged. The motor will automatically restart when it completely cools.
B. AIR COMPRESSOR PUMP: The pump is used to compress the air and discharge it into the tank via the
piston moving up and down in the cylinder.
C. PRESSURE SWITCH: The switch is used to start or stop the air compressor. It is operated manually. When in
ON position, it allows the motor to start when the air tank pressure is below the factory set cut-in pressure and
allows the motor to stop when the air tank pressure reaches the factory set cut-out pressure. ALWAYS set this
switch to OFF when the unit is not being used, and before unplugging the unit.
D. PRESSURE RELIEF VALVE: The valve is used to prevent system failures by relieving pressure from the
system when the pressure reaches the preset level while the pressure switch does not shut down the motor. It
will pop open automatically or you can pull the ring on the valve to make it.
E. AIR PRESSURE REGULATOR: The regulator is used to adjust line pressure to the tool you are using. Turn
the knob clockwise to increase pressure and counter-clockwise to decrease pressure.
Never exceed the maximum working pressure of the tool.
F. TANK PRESSURE GAUGE: The gauge is used to measure the pressure level of the air stored in the tank. It
is not adjustable by the operator, and does not indicate line pressure.
G. REGULATED PRESSURE GAUGE: The gauge is used to measure the regulated outlet pressure.
H. AIR LINE OUTLET: The outlet is used to connect 1/4” NPT air hose.
I. AIR TANK DRAIN VALVE: The drain valve is used to remove moisture from the air tank after the unit is shut
off.
Never attempt to open the drain valve when over 10 PSI of air pressure is in the tank.
J. AIR TANK: The tank is used to store the compressed air.
K. POWER CORD: This product is for use on a nominal 115-volt circuit and should be grounded. A cord with a
grounding plug, as K showed, should be used. Make sure that the product is connected to an outlet having the
same configuration as the plug (see Figure 1). No adapter should be used with this product.
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BEFORE YOU START
General Performance & Usage
This Motomaster® Air Compressor is ideal for a wide-range of automotive applications from fastening to
greasing and engine cleaning. The 5-gallon twin tank design provides optimum pressure. It features a 2HP
(peak) induction motor for quiet operation and a cast-iron, oil-lubricated pump for long-lasting, reliable
performance. It comes standard with a 25’ coil hose and attachment fittings.
Compatible Compressor & Air Tool - Guidelines for Proper Usage & Operation
Always ensure the use of appropriately matched air tools with your Motomaster® Air Compressor. Be sure
that the air compressor being used can supply the appropriate volume, pressure and delivery rate of air to
the tool(s) without running continuously. Using tools or combinations of tools that together or separately
require more than the air compressor can deliver will void the air compressor guarantee/warranty.
EXTENSION CORDS:
Avoid the use of extension cords whenever possible. If an extension
cord must be used, it must have a minimum wire size of 12 AWG, and
must be no longer than 50’ (15 m). Use only a 3-wire extension cord
that has a 3-pronged grounding plug, and plug it into a 3-holed outlet
that is suitable for the compressor’s plug.
Whenever possible, utilize a longer air hose instead of an
extension cord.
Before You Start – Air System:
1. A filter-regulator-lubricator is recommended and should be located as close to the air-powered tool as
possible. (see Fig.4)
2. If a filter-regulator-lubricator is not installed, place 2-6 drops of compressor oil into the NPT inlet plug of
your air-powered tools before each use.
3. If installed, keep air filter clean. A dirty filter will reduce the air pressure to the tool causing a reduction in
power, efficiency and performance in general.
4. For better performance, install a quick connector in your tool and quick coupler on the hose.
5. Be sure all connections in air supply system are sealed to prevent air loss.
Grounded
outlet
115V/15 A
Grounding Pin
Plug
Figure 1
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BEFORE YOU START - ASSEMBLY INSTRUCTIONS
1. Unpack the air compressor. Inspect the unit for damage .If the unit has been damaged in transit, contact
the carrier and complete a damage claim, Do this immediately because there is time limitation to damage
claims.
The carton should contain:
Air compressor,
Accessories,
Owner’s manual.
2. Check the air compressor’s identification label to ensure that you have received the model ordered, and
that it has the required pressure rating for its intended use.
3. Position the air compressor according to following guidelines:
a. Position the air compressor near a grounded electrical outlet.
b. The compressor must be at least 12” inches (31 cm) from any wall or obstruction, in a clean,
well-ventilated area, to ensure sufficient air flow and cooling.
c. In cold climates, store portable air compressors in a heated building when not in use. This will
reduce problems with motor starting and freezing of water condensation.
d. Place air compressor on the floor or a hard, level surface. The air compressor must be level to
ensure proper drainage of the moisture in the tank.
4. Connect an air hose to the compressor hose outlet (see Figure 2).
5. Refer to the air compressor‘s identification label for the unit’s voltage and amperage requirements.
USE A DEDICATED CIRCUIT
For best performance and reliable starting, the air compressor should be plugged into a
dedicated circuit, as close as possible to the fuse box or circuit breaker.
The compressor will use the full capacity of a typical 15 amp household circuit. If any other
electrical devices are drawing from the compressor’s circuit, the air compressor may fail to start.
Low voltage or an overloaded circuit can result in sluggish starting that causes the motor overload
protection system or circuit breaker to trip, especially in cold conditions.
NOTE: Acircuit breaker is recommended. If the air compressor is connected to a circuit protected by a
fuse, use dual element time delay fuses (Buss Fusetron type “T” only).
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Figure 2

BEFORE YOU START
BREAK-IN PERIOD OF THE PUMP
NOTE:The pump is shipped WITHOUT oil. Before starting, the break-in oil provided in an oil bottle should
be poured in the pump through the oil nozzle. The break-in oil should be changed after 8 hours of
operation. To reduce maintenance and repair problems, use only premium compressor oil. SAE
10W-30 all weather air compressor oil is recommended for general use.
NOTE: Always dispose of used oil in an environmentally-friendly manner.
1. Check the oil level in the pump through the oil sight glass. The pump oil level must be between A1 and
A2. Do not overfill or underfill (see A).
2. Turn the pressure switch to the OFF position (see B).
3. Open the tank drain valve (see C). Turn in the counter-clockwise direction.
4. Plug in the power cord
5. Turn the pressure switch to the ON position (see B). The unit will start. Allow the unit to run for 30
minutes to break in the internal parts. After 30 minutes, if the unit does not operate properly, shut
down immediately and contact Product Service.
6. After 30 minutes, turn the pressure switch to the OFF position.
7. Close the tank drain valve. Turn in the clockwise direction.
8. Turn the pressure switch to the ON position. The unit will start and fill the tank to the cut-out pressure
and stop.
NOTE: The pressure switch will restart the motor automatically as compressed air is used.
C
C
D
B
OFF
ON
CLOSE
OPEN
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Operating Instructions
Daily Start-Up
If the pump has been transported or turned upside down (even partially), allow
the pump to sit in a normal, upright position for approximately 10 minutes before starting.
1. Before starting, check the oil sight glass to ensure that oil level in the pump is at the required level.
2. Turn the pressure switch to the OFF position.
3. Close the tank drain valve.
4. Plug in the power cord.
High temperatures are generated by the electric motor and the pump.
To prevent burns or other injuries, DO NOT touch the air compressor while it is running.
Allow it to cool before handing or servicing. Keep children away from the air compressor
at all times.
5. Turn the pressure switch to the ON position.
6. Adjust the pressure regulator to the working pressure of the tool.
When adjusting from a higher to a lower pressure, turn the knob counter-clockwise past the desired
setting, and then turn clockwise to reach the desired pressure. DO NOT exceed operating pressure of
the tool or accessory being used.
Shut-Down Procedure
1. Switch the pressure switch to the OFF position.
2. Unplug the power cord.
3. Reduce pressure in the tank through the outlet hose. You can also pull the relief valve ring and keep it
open to relieve pressure in the tank (see D).
Escaping air and moisture can propel debris that may cause eye injury. Wear safety
goggles when opening drain valve.
4. Open the drain valve (see C) to allow moisture to drain from the tank.
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MAINTENANCE
To avoid personal injury, always shut off and unplug the unit and relieve all air
pressure from the system before performing any service on the air compressor.
Regular maintenance will ensure trouble-free operation. The items listed in the chart should be inspected
on a regular basis.
ITEM DESCRIPTION/REASON
SERVICE
INTERVAL
Drain the tank.
Through normal operation of your air compressor,
condensation water will accumulate in the tank. To prevent
corrosion of the tank from the inside, condensation must
be drained at the end of every workday. Be sure to wear
protective goggles. Relieve the air pressure in the system
and open the drain valve on the bottom of the tank to drain.
In cold conditions, it is especially important to drain
the tank after each use to reduce the chance of
problems resulting from the freezing of condensation
water.
Daily
Check the oil. Check the oil level in the pump through the oil sight glass.
The pump oil level must be within the red circle.
Do not overfill or underfill. Daily
Check the relief valve.
Pull/activate the relief valve daily to ensure that it is
operating properly and to clear the valve of any possible
obstructions. Daily
Clean the air filter.
Adirty air filter will reduce air compressor performance and
life.
To avoid any contamination of the inside pump, the filter
should be cleaned frequently and replaced on a regular
basis. Foam filters should be cleaned in warm and soapy
water.
Weekly
Test for leakages.
Check that all connections are tight. Small leaks in any of
the tank, hoses, connections or transfer tubes will
substantially reduce the air compressor and tool
performance.
Spray a small amount of soapy water around the area of
suspected leaks with a spray bottle. If bubbles appear,
repair, replace or re-seal the faulty component. Do not over
tighten any connections.
Monthly
Storage.
Before storing the unit for a long period, use an air blow
gun to clean all dust and debris from the air compressor.
Disconnect and coil the power cord up. Clean the filter
element and filter housing. Drain all moisture from the tank.
Pull the pressure relief valve to release all pressure from
the tank. Cover the entire unit to protect it from moisture
and dust.
N/A
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