Clarke MMA Series Instruction Manual

WARNING: Read these instructions before using the machine
WARNING: A suitable welding headshield must be worn during use
OPERATION & MAINTENANCE
INSTRUCTIONS
ORIGINAL INSTRUCTIONS GC0219 ISSUE 1
MMA INVERTER WELDER
MODEL NO: MMA80
PART NO: 6012153

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INTRODUCTION
Thank you for purchasing this CLARKE Welder.
Before attempting to operate the machine, it is essential that you read this
manual thoroughly and carefully follow all instructions given. In doing so you
will ensure the safety of yourself and that of others around you, and you can
also look forward to the product giving you long and satisfactory service.
Ensure the welder and its components suffered no damage during transit and
that all components are present. Should any loss or damage be apparent,
please contact your CLARKE dealer immediately.
GUARANTEE
This CLARKE product is guaranteed against faulty manufacture for a period of
12 months from the date of purchase. Please keep your receipt as proof of
purchase.
This guarantee is invalid if the product is found to have been abused or
tampered with in any way, or not used for the purpose for which it was
intended.
Faulty goods should be returned to their place of purchase, no product can
be returned to us without prior permission.
This guarantee does not effect your statutory rights.
TECHNICAL SPECIFICATIONS
Power Supply 230V/50Hz/1ph
Rated Max Input Current I1Max/I1eff 15.8A/7.1A
Ingress Protection IP21S
Operating range 20-80 Amp
Range of welding electrodes 1.6-2.5 mm
Weight 3.77 kg (machine only)
Dimensions (L x W x H) 288 x 125 x 195 mm

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SAFETY WARNINGS
ELECTRIC SHOCK
1. Do not touch live electrical parts.
2. Never use electrode holders or cables which are damaged.
3. Keep the working environment, equipment, cables and clothing free from
grease, oil, moisture and dirt.
4. Ensure the welding machine has been correctly earthed.
5. The operator must be insulated from the floor and work bench using a dry
insulation mat.
6. Always ensure a second person is present in case of accident.
7. Keep welding cables away from power cables.
8. Regularly inspect the condition of the cables for signs of damage.
9. Remove the plug from the mains socket when not in use.
10. Ensure the earth connector is secured to bare metal adjacent to the weld,
and when not in use insulated for safety. - Keep all equipment well
maintained.
FUMES & GASES
1. The welding process generates hazardous fumes as a by-product.
Inhalation of these fumes is hazardous to health.
2. Keep your face away from the weld to avoid breathing the fumes.
3. If welding in confined spaces ensure adequate ventilation and use a fume
extractor.
4. By-products of welding can react to create a toxic/explosive environment.
FIRE OR EXPLOSION
1. Welding can cause fire and explosions. Precautions should be taken to
prevent these hazards.
WARNING: WHEN USING ELECTRICAL TOOLS, BASIC SAFETY
PRECAUTIONS SHOULD ALWAYS BE FOLLOWED TO REDUCE THE RISK OF
FIRE, ELECTRIC SHOCK AND PERSONAL INJURY
WARNING: READ ALL THESE INSTRUCTIONS BEFORE ATTEMPTING TO
OPERATE THIS PRODUCT AND KEEP THESE INSTRUCTIONS IN A SAFE PLACE.

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2. Before starting work ensure the area is clear of flammable materials and
move any combustible materials to a safe distance, especially substances
likely to generate a dangerous vapours.
3. The welding arc can cause serious burns. Avoid contact with skin.
4. Sparks and molten metal may be ejected during welding. Take
precautions to prevent fire.
5. Sparks and molten metal can pass through gaps. Be aware that fire can
start out of sight.
6. Do not weld to pressurised containers. or containers containing flammable
vapours e.g. fuel tanks.
7. Always have appropriate fire fighting equipment to hand suitable for use in
electrical environments.
8. Avoid carrying any fuels with you e.g. cigarette lighters or matches.
PERSONAL PROTECTION
1. The body should be protected by suitable clothing.
2. The use of neck protection may be necessary against reflected radiation.
3. Arc machines generate a magnetic field which is detrimental to
pacemakers. Consult your doctor before going near active welding
equipment/operations.
4. The UV and IR radiation generated by welding is highly damaging to the
eyes, causing burns. This can also affect the skin.
5. Always use suitable welding shields equipped with appropriate filters.
6. Where there are pedestrians and traffic ensure a protective screen is used
to avoid accidental arc glare.
7. Do not weld in the vicinity of children or animals and ensure no one is
looking before striking an arc.
8. Wear hearing protection if required.
9. Allow the weld to cool. Hot metal should never be handled without gloves.
10. Take care when adjusting or maintaining the electrode/holder, that it has
had time to cool sufficiently and the welder is disconnected from the mains
supply.
11. First aid facilities and a qualified first aid person should be available unless
medical facilities are close by, for immediate treatment of flash burns of
the eyes and skin burns.
12. Flammable hair sprays/gels should not be used by persons welding.

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PROTECTIVE CLOTHING
1. Wear gauntlet type gloves designed for use when welding.
2. Wear a fire resistant apron and protective shoes.
3. Wear cuffless trousers (not turned up) to avoid catching sparks and slag.
4. Avoid wearing oily or greasy clothing.
5. Wear protective head and shoulder coverings if welding overhead.
6. Wear a helmet with safety goggles or glasses with side shields underneath,
appropriate filter lenses or plates (protected by clear glass). This is a MUST
for welding (and chipping) to protect the eyes from radiant energy and
spatter. Replace cover glass when broken, pitted, or spattered.
NOTE: All protective wear inc. masks & head shields MUST comply with
Personal Protective Equipment Directive 89/686/EEC.
ADDITIONAL SAFETY PRECAUTIONS FOR WELDING
1. Always ensure that there is ample free air circulating around the outer
casing of the machine, and that the louvres are unobstructed.
2. Always inspect the cable before use to ensure it is in good condition.
3. Always remove all flammable materials from the welding area.
4. Always keep a fire extinguisher handy;-Dry Powder, CO2or BCF, NOT Water.
5. Never remove the cover panels unless the machine is disconnected from
the power supply, and never use the machine with the panels removed.
6. Never attempt any electrical or mechanical repair unless you are a
qualified technician. If you have a problem with the machine contact your
local CLARKE dealer.
7. Never use or store in a wet/damp environment.
8. Never continue to weld, if, at any time, you feel even the smallest electric
shock. Stop welding IMMEDIATELY and DO NOT attempt to use the
machine until the fault is diagnosed and corrected.
9. Never allow the earth cable or hose to become wrapped around the
operator or any person in the vicinity.
10. Never change electrodes with bare hands or damp gloves.
• Please read these instructions carefully and retain for future reference.

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SAFETY SYMBOLS
ENVIRONMENTAL RECYCLING POLICY
Through purchase of this product, the customer is taking on the
obligation to deal with the WEEE in accordance with the WEEE
regulations in relation to the treatment, recycling & recovery and
environmentally sound disposal of the WEEE.
In effect, this means that this product must not be disposed of with general
household waste. It must be disposed of according to the laws governing
Waste Electrical and Electronic Equipment (WEEE) at a recognised disposal
facility.
If disposing of this product or any damaged components, do not dispose of
with general waste. This product contains valuable raw materials. Metal
products should be taken to your local civic amenity site for recycling of metal
products.
Read this instruction
booklet carefully
before use.
Do not expose to rain.
Wear eye protection Recycle unwanted
materials instead of
disposing of them as
waste. All tools,
accessories and
packaging should be
sorted, taken to a
recycling centre and
disposed of in a manner
which is compatible
with the environment.
Wear protective gloves
Wear a dust mask

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ELECTRICAL CONNECTIONS
Connect the mains lead to a standard, 230 Volt (50Hz) electrical supply
through an approved 13 amp BS1363 plug, or a suitably fused isolator switch.
If the plug has to be changed because it is not suitable for your socket or
because of damage, it must be removed and a replacement fitted, following
the wiring instructions shown below. The old plug must be discarded safely as
insertion into a power socket could cause an electrical hazard.
The wires in the mains lead should be
wired up in accordance with the
following colour code:
• Connect the GREEN & YELLOW
coloured wire to the plug
terminal marked with a letter E
or .
• Connect the BROWN coloured
wire to the plug terminal
marked a letter “L”.
• Connect the BLUE coloured wire to the plug terminal marked a letter
“N”.
We strongly recommend that this machine is connected to the mains supply
via a Residual Current Device (RCD). If you are not sure, consult a qualified
electrician. DO NOT try to carry out any repairs yourself.
WARNING! READ THESE ELECTRICAL SAFETY INSTRUCTIONS
THOROUGHLY BEFORE CONNECTING THE PRODUCT TO THE
MAINS SUPPLY.
WARNING: THE WIRES IN THE POWER CABLE OF THIS PRODUCT ARE
COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:
BLUE = NEUTRAL BROWN = LIVE YELLOW AND GREEN = EARTH.

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OVERVIEW
The following components are supplied with the MMA80 welding machine;
1 Power on LED (green) 7 Negative Terminal
2 High temperature LED (yellow) 8 Earth Cable
3 Welding current adjustment knob 9 Electrode holder
4 Power Switch (behind unit) 10 Carrying Strap
5 Welding current display 11 Welding Mask
6 Positive Terminal
• Electrode holder with cable • Earth clamp with cable
• Face Mask (in two parts plus
handle)
• Clear protective glass lens for
mask
• Dark glass filter lens (Shade no 11)
for mask

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MAIN FEATURES
INVENTORY
The following components are supplied with the 80 Amp welding machine;
• Electrode holder with cable
• Earth clamp with cable
• Face Mask (in two parts plus handle)
• Dark glass filter lens (Shade no 11) for mask
• Clear protective glass lens for mask
THE WELDING SHIELD
1. Push the two halves of the shield
together as shown, making sure
the hooks and pins on the side
engage correctly.
2. Place the handle into position
and secure using the plastic nut
provided.
ARC-FORCE Automatically increases the current to prevent the elec-
trode sticking when operating with a short arc length .
HOT START Increases the welding current at the beginning of the
welding process.
ANTI-STICK The electrode can be easily withdrawn without it
becoming damaged.

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3. Working from the inside of the
shield, insert the clear glass lens
into the recess in the shield,
followed by the dark glass lens.
• The clear glass must be inserted
first.
4. Insert the two plastic screws to
clamp the glass lens from the
inside of the mask.
When replacing the glass lenses only
use parts supplied by Clarke International. The shaded filter lens is a certified,
specific optical glass and should not be exchanged for any other type.
• The clear glass cover lens should be replaced when it becomes badly
pitted.
SETUP OF THE WELDER
CONNECTING THE CABLES
Make sure the on/off switch on the rear panel is in the OFF position before
connecting the leads.
1. Connect the earth (ground)
cable to the negative terminal (-).
2. Connect the electrode holder
cable to the positive terminal (+).

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PREPARING THE WORKPIECE
The area being welded should be perfectly clean. Any coating, plating or
corrosion must be removed, otherwise a good weld will be impossible to
achieve.
FITTING THE WELDING ROD
1. Select the appropriate welding rod and grasp it in the welding rod holder.
• It should be approximately the same thickness as the metal being
welded. Refer to the table below.
USING THE WELDER
1. Plug the welder in to the mains supply and switch on with the switch at the
rear.
• The green “power on” LED will illuminate.
2. Attach the earth clamp firmly to the workpiece as close as possible to the
point of weld.
• Ensure that the earth clamp is attached to clean, solid metal. If necessary
thoroughly clean with a wire brush to guarantee a good connection.
SETTING THE WELDING CURRENT
1. Select the welding current by
turning the adjustment knob and
observing the setting on the
digital display.
• The table below is an indicator of
the welding rod used for a given
thickness of material.
This is intended as a guide only.
2. With practice you will get a feel for the best current settings for different
welding rod thicknesses.
SIZE OF WELDING ROD / THICKNESS OF METAL Display reading
1.6 mm 1.0 - 2.0 mm 20 - 30 A
2 mm 1.5 - 2.5 mm 30 - 50A
2.5 mm 1.0 - 3.0 mm 50 - 80A

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STRIKING AN ARC
IMPORTANT: BEFORE YOU STRIKE AN ARC, ALWAYS BRING THE FACE SHIELD UP
TO PROTECT YOUR EYES.
1. Line up the electrode exactly over the spot where you want to strike the
arc.
2. Position your shield in front of your face and tap down firmly with the
electrode. Once you tap down and contact is made, you must instantly
raise the electrode to the required arc gap.
• The arc gap should be roughly the same as the diameter of the
electrode.
• If you withdraw the electrode too far once the arc is struck you will
lose the arc and have to try again.
NOTE: One thing that usually happens when you are striking an arc is that the
electrode sticks to the work. It should come unstuck with a sharp tug.
If it will not free easily, then turn off the welder immediately as it will
quickly start to overheat, then give the join a tap from a chipping
hammer. As you get more experienced this will happen less.
3. Once the arc is struck, move the electrode along its intended path,
keeping the tip in the molten pool at all times.
• You must also get used to feeding down the electrode steadily as it
burns away.
• An even crackling noise should be heard, which is an indication of a
good weld.
4. Inspect the job carefully, the area of weld should be a complete fusion of
the electrode and parent metal (s).
• Any slag which forms on the surface should be chipped away with a
suitable hammer/brush.
• If the resultant weld looks messy and irregular, this is an indication of
porosity or slag contamination and you have almost certainly failed to
achieve the correct combination of working speed and current. This is a
common problem, so do not worry as practice will quickly cure this.
5. The electrode will need to be replaced when only 2-3 cm remains clear of
the holder. Take care of the hot used electrode.
6. If the machine stops after a period of work and the yellow LED comes on,
the thermal overload device has intervened. Wait until the machine has
cooled down and the light should go out. You can now continue welding.

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WELDING PITFALLS
The arc welding technique is an acquired skill and requires considerable
practice before perfect results are obtained. The diagrams below will help to
explain the pitfalls in your technique and how to overcome them.
ARC TOO SHORT
This causes irregular masses of weld to be deposited, with
slag contamination on an uneven surface.
ARC TOO LONG
This causes poor penetration resulting in a weak weld with
excessive spatter and porosity. The surface of the weld is
rough and the arc makes a hissing sound.
ELECTRODE MOVED TOO SLOWLY
This causes a very wide and heavy deposit which overlaps
at the sides. It is wasteful both in terms of time and electrode
use.
ELECTRODE MOVED TOO QUICKLY
This causes poor penetration with a ‘stringy’ and incomplete
weld deposit. Slag is very hard to remove.
CURRENT TOO LOW
This causes poor penetration and causes the electrode to
easily stick to the workpiece. It also results in a very irregular
and high weld deposit. Slag is very hard to remove.
CURRENT TOO HIGH
This causes excessive penetration with spatter and a deep
pointed crater. It may also cause holes to be burned in the
workpiece.
This burns electrodes very quickly.
THE PERFECT WELD
With the correct combination of arc length, current
regulation, inclination and speed of the electrode, you will,
with practice produce the perfect weld.
This should be regular with uniform ripples and no slag
contamination. The arc will make a steady crackling sound.

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MAINTENANCE
The welder should be kept clear of any accumulation of dust which could
block the air ventilation louvres and prevent proper cooling. If working in a
dusty atmosphere, brush any dust downwards or use compressed air to
remove dust.
Always inspect both cables before use to ensure they are in perfect condition
and that the earth clamp is clean and secured correctly to the cable.
Consult your CLARKE dealer for any internal repairs if necessary.
STORAGE
1. Turn off the welder and disconnect it from the power supply.
2. Remove and coil the earth cable and electrode /cables and store them
carefully.
Cover the unit and store in a dry location.
DUTY CYCLE
This welder is covered by regulations BS-EN60974-1(2012) and BS-EN 60974-10
(2014), where the Duty Cycle is expressed as a percentage of time the
machine may be used in a given period, for a specified welding current.
e.g. When welding at 80 Amps the machine may be used for 2 minutes (20%)
in any10 minute period, or the machine may be used continuously, (100%)
when welding at 36 Amps or less.
WARNING: ELECTRICITY CAN KILL - NEVER TOUCH LIVE ELECTRICAL
COMPONENTS.
WARNING: DISCONNECT THE POWER SUPPLY BEFORE ALL INSPECTION
AND MAINTENANCE OPERATION BEWARE HOT SURFACES.
WARNING: ALWAYS LET THE POWER SUPPLY COOL DOWN BEFORE
ACCESSING INTERNAL COMPONENTS.

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RATING PLATE
1 Name/address of manufacturer 13 Conventional Load Voltage
2 Model number/ part number 14 Energy Input symbol
3 Batch number 15 Rated supply voltage
4 Single phase transformer 16 Rated maximum supply current
5 British Standards applied 17 Maximum effective supply current
6 Manual metal arc welding with
covered electrode
18 N/A
7 This symbol indicates that the
unit is suitable for carrying out
welding operations in an
environment which has an
increased risk of electric shock.
19 N/A
8 Welding Current symbol 20 N/A
9Ratedno-loadvoltage 21N/A
10 Max welding current and
corresponding load voltages
22 Degree of protection
11 Duty Cycle Percentage 23 Class of protection
12 Rated Welding current

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TROUBLESHOOTING
DEFECT CAUSES SUGGESTIONS
Unable to strike an
arc
Bad clamp connection.
Inverter printed circuit
board is defective.
Check clamp connection.
Contact your nearest
CLARKE dealer.
No output voltage Overheated machine (the
yellow LED should be on).
Wait for thermal cutout to
reset.
Internal relay has failed. Contact your nearest
CLARKE dealer.
Inverter printed circuit is
defective.
Contact your nearest
CLARKE dealer.
Wrong output
current
Current selector control is
defective.
Contact your nearest
CLARKE dealer.
Low power supply voltage. Check the mains distribution
system.
Porosity of welds Acid electrode on steel
with high sulphur content.
Electrode oscillates too
much.
Workpieces are too far
apart.
Workpiece being welded is
cold.
Use basic electrode.
Move edges to be welded
closer together. Move slowly
at the beginning.
Cracks in weld Material being welded is
dirty (e.g.oil, paint, rust,
oxides).
Not enough current.
Cleaning the workpiece
before welding is an
essential method of achiev-
ing neat weld beads.
Poor penetration Low current, high welding
rate, reversed polarity.
Electrode inclined in
position opposite to it's
movement.
Ensure operating variables
are correct and improve
preparation of work pieces.
Profile defects Welding parameters are
incorrect.
Pass rate is incorrect
operating parameter
requirements.
Electrode not inclined
constantly while welding.
Follow basic and general
welding principles.

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ACCESSORIES
The following are some of the accessories available from your CLARKE dealer.
Please quote the part numbers shown below:
A selection of
• welding headshields
• replacement lenses.
• welding clamps,
• welding screens,
•gauntlets,
•aprons
are also available from your Clarke dealer.
Arc is unstable Insufficient current. Check condition of
electrode and earth wire
connection.
Electrode melts
obliquely
Electrode core is not
centred.
Magnetic blow
phenomenon.
Replace electrode.
Connect two earth wires
to opposite sites of the
work piece.
Machine stops
working.
Poor ventilation or high
environmental temperature
has caused the overheating
protection to operate.
Improve ventilation.
DESCRIPTION PART NUMBER
1.6 mm Welding Electrodes 3050580
2 mm Welding Electrodes 3050582
2.5 mm Welding Electrodes 3050586
DEFECT CAUSES SUGGESTIONS

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PARTS LIST/DIAGRAM
NO DESCRIPTION NO DESCRIPTION
1 CARRY STRAP 11 COOLING FINS 2
2 MACHINE COVER 12 COOLING FINS 3
3 POWER SWITCH 13 RECTIFIER
4 BOTTOM PANEL 14 IGB TRANSISTOR
5 WELDING CURRENT KNOB 15 ELECTROLITIC CAPACITOR
6 LED INDICATOR 16 PRINTED CIRCUIT BOARD
7 DIN CONNECTOR 17 FAN
8 MAIN TRANSFORMER 18 FAN COVER
9 FAST RECOVERY DIODE 19 BACK PANEL
10 COOLING FINS 1 20 FRONT PANEL

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DECLARATION OF CONFORMITY