Clarke Arc/Tig90 Installation and operation manual

ARC/TIG INVERTERS
Model Nos. Arc/Tig90, Arc/Tig120 & Arc/Tig150
ARC/TIG INVERTERS
OPERATING & MAINTENANCE
INSTRUCTIONS 0901

227
The full technical specification for your inverter is to be found printed in a
table on the back panel of the machine.
The meaning of the markings and symbols shown in the table are explained
as follows.
HCode letter for degree of insulation
nhSymbol for the No. reference electrodes being melted with the welding
power source at the hot state, without operation of the thermal cut-out.
IP_ _ Degree of protection (e.g. IP21)
I1max_ _ASymbol, rated value and dimension of the max. supply current
_ _ ASize of the necessary main fuse
U1_ _ _VRated value of the supply voltage
ncSymbol for the number of reference electrodes capable of
being melted with the welding power source, starting from the
cold state without operation of the thermal cut-out
I2ASymbol and dimension for the welding current
mm Symbol and dimension for the diameter of reference electrodes
_ _ _ _ _ _AI2Min. and Max. rated value of the welding current
50Hz Rated frequency for alternating current
Symbol for dropping characteristic
Symbol for manual arc welding and covered electrodes
Symbol for the mains supply and No. of phases
1Single Phase Transformer
1
U0_ _ _ _ _ _VMin. and Max. rated no load voltage
EXPLANATION OF ELECTRICAL SYMBOLS
XDuty Cycle (expressed as a %, i.e. 20%)
S1(THERM)Rated value of Thermal Overload

Thank you for purchasing this CLARKE ARC/TIG Welder.
Before attempting to operate this machine, please read this leaflet thoroughly
and follow the instructions carefully, in doing so you will ensure the safety of your-
self and that of others around you, and you can look forward to the welder giving
you long and satisfactory service.
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.
CONTENTS PAGE
Electromagnetic Interference (EMC) ................................................. 4
Safety Precautions ................................................................................. 6
Additional Safety Precautions for Tig Welding ................................. 11
Principles of Operation Arc Welding ................................................ 13
TIG Welding ................................................. 14
Electrical Connections ........................................................................ 15
Welding Techniques ..... Arc ............................................................... 16
TIG ................................................................ 17
Maintenance ....................................................................................... 20
Accessories........................................................................................... 21
Specifications ....................................................................................... 21
Parts Lists and Diagrams ...................................................................... 22
Wiring Diagram .................................................................................... 24
Parts & Service Contacts .................................................................... 26
Explanation of Electrical Symbols ...................................................... 27
3
26

ELECTROMAGNETIC INTERFERENCE (EMC)
Whilst this unit complies with EMC regulations, the user is responsible for installing
and using the welding equipment according to the manufacturers instructions. If
electromagnetic disturbances are detected then it shall be the responsibility of
the user of the welding equipment to resolve the situation. In some cases this
remedial action may be as simple as earthing the welding circuit, see ‘Note’. In
other cases it could involve constructing an electromagnetic screen enclosing
the power source and the work complete with associated input filters. In all cases
electromagnetic disturbances must be reduced to the point where they are no
longer troublesome.
Note - The welding circuit may or may not be earthed for safety reasons. Changing
the earthing arrangements should only be authorised by a person who is
competent to assess whether the changes will increase the risk of injury, e.g. by
allowing parallel welding current return paths which may damage the earth circuits
of other equipment.
1.ASSESSMENT OF AREA
Before installing welding equipment the user shall make an assessment of potential
electromagnetic problems in the surrounding area. Avoid using your inverter in
the vicinity of:
a) other supply cables, control cables, signalling and telephone cables;
above, below and adjacent to the welding equipment;
b) radio and television transmitters and receivers;
c) computer and other control equipment;
d) safety critical equipment, e.g. guarding of industrial equipment;
e) pacemakers and hearing aids etc;
f) equipment used for calibration or measurement;
g) other equipment in the environment. The user shall ensure that other
equipment being used in the environment is compatible. This may
require additional protection measures;
It may be possible to avoid the above by changing the time of day that welding
or other activities are to be carried out.
The size of the surrounding area to be considered will depend on the structure of
the building and other activities that are taking place. The surrounding area may
extend beyond the boundaries of the premises.
2. METHODS OF REDUCING EMISSIONS
2.1 Mains supply
Welding equipment should be connected to the mains supply according to the
manufacturers recommendations. If interference occurs, it may be necessary to
425
WIRING DIAGRAM
ARC/TIG150

5
take additional precautions such as filtering of the mains supply. Consideration
should be given to shielding the supply cable of permanently installed welding
equipment, in metallic conduit or equivalent. Shielding should be electrically
continuous throughout its length. The shielding should be connected to the welding
power source so that good electrical contact is maintained between the conduit
and the welding power source enclosure.
2.2 Maintenance of the welding equipment
The welding equipment should be routinely maintained according to the
manufacturers recommendations. All access and service doors and covers should
be closed and properly fastened when the welding equipment is in operation.
The welding equipment should not be modified in any way except for those
changes and adjustments covered in the manufacturers
instructions. In particular, the spark gaps of arc striking and stabilizing devices should
be adjusted and maintained according to the manufacturers recommendations.
2.3 Welding cables
The welding cables should be kept as short as possible and should be positioned
close together, running at or close to the floor level.
2.4 Equipotential bonding
Bonding of all metallic components in the welding installation and adjacent to it
should be considered. However, metallic components bonded to the work piece
will increase the risk that the operator could receive a shock by touching these
metallic components and the electrodes at the same time. The operator should
be insulated from all such bonded metallic components.
2.5 Earthing of the workpiece
Where the workpiece is not bonded to earth for electrical safety, nor connected
to earth because of its size and position, e.g. ships hull or building steelwork, a
connection bonding the workpiece to earth may reduce emissions in some, but
not all instances.
Care should be taken to prevent the earthing of the workpiece increasing the risk
of injury to users, or damage to other electrical equipment.
Where necessary, the connection of the workpiece to earth should be made by
a direct connection to the workpiece, but in some countries where direct
connection is not permitted, the bonding should be achieved by suitable
capacitance, selected according to national regulations.
2.6 Screening and shielding
Selective screening and shielding of other cables and equipment in the surrounding
area may alleviate problems of interference. Screening of the entire welding
installation may be considered for special applications.
WIRING DIAGRAM
ARC/TIG90
ARC/TIG120
24

SAFETY PRECAUTIONS
WARNING:
As with all machinery, there are certain hazards involved with their operation
and use. Exercising respect and caution will considerably lessen the risk of
personal injury. However, if normal safety precautions are overlooked, or
ignored, personal injury to the operator may result.
FAILURE TO FOLLOW THESE RULES MAY RESULT IN SERIOUS PERSONAL INJURY
1. GENERAL PRECAUTIONS
A) Burn prevention
Wear protective clothing - gauntlet gloves designed for use in welding, hat, and
protective shoes. Button shirt collar and pocket flaps, and wear cuffless trousers to
avoid entry of sparks and slag. Wear helmet with safety goggles or glasses with side
shields underneath, appropriate filter lenses or plates (protected by clear cover
glass). This is a MUST for welding or cutting, (and chipping) to protect the eyes from
radiant energy and flying metal. Replace cover glass when broken, pitted, or
spattered. Avoid oily greasy clothing. A spark may ignite them. Hot metal such as
electrode stubs and workpieces should never be handled without gloves. First aid
facilities and a qualified first aid person should be available for each shift unless
medical facilities are close by for immediate treatment of flash burns of the eyes
and skin burns. Ear plugs should be worn when working overhead or in a confined
space. A hard hat should be worn when others work overhead. Flammable hair
preparations should not be used by persons intending to weld or cut.
B) Toxic fume prevention
Severe discomfort, illness or death can result from fumes, vapours, heat, or oxygen
enrichment or depletion that welding (or cutting) may produce. Prevent them
with adequate ventilation. NEVER ventilate with oxygen. Lead-, cadmium-, zinc-,
mercury- and beryllium-, bearing materials, when welded (or cut) may produce
harmful concentrations of toxic fumes. Adequate local exhaust ventilation must
be used, or each person in the area as well as the operator must wear an air-
supplied respirator. For beryllium, both must be used. Metals coated with or
containing materials that emit toxic fumes should not be heated unless coating is
removed from the work surface, the area is well ventilated, or the operator wears
an air-supplied respirator. Work in a confined space only while it is being ventilated
and, if necessary, while wearing an air-supplied respirator. Vapours from chlorinated
solvents can be decomposed by the heat of the arc (or flame) to form PHOSGENE,
a highly toxic gas, and other lung and eye irritating products. The ultraviolet
(radiant) energy of the arc can also decompose trichloroethylene and
perchloroethylene vapours to form phosgene. DO NOT WELD or cut where solvent
vapours can be drawn into the welding or cutting atmosphere or where the radiant
energy can penetrate to atmospheres containing even minute amounts of
trichloroethylene or perchloroethylene.
6
PARTS DIAGRAM
Arc/Tig90 & 120
Arc/Tig150
23

7
C) Fire and explosion prevention
Causes of fire and explosion are:
1) combustibles reached by the arc, flame, flying sparks, hot slag or heated
material;
2) misuse of compressed gases and cylinders;
3) short circuits.
BE AWARE THAT flying sparks or falling slag can pass through cracks, along pipes,
through windows or doors, and through wall or floor openings, out of sight of the
goggled operator. Sparks and slag can fly 10m.
To prevent fires and explosion: keep equipment clean and operable, free of oil,
grease, and (in electrical parts) of metallic particles that can cause short circuits.
If combustibles are in area, do NOT weld or cut. Move the work if practicable, to
an area free of combustibles.
Avoid paint spray rooms, dip tanks, storage areas, ventilators. If the work cannot
be moved, move combustibles at least 10m. away out of reach of sparks and
heat; or protect against ignition with suitable and snug fitting, fire- resistant covers
or shields.
Walls touching combustibles on opposite sides should not be welded on (or cut).
Walls, ceilings, and floor near work should be protected by heat resistant covers
or shields. Fire watcher must be standing by with suitable fire extinguishing
equipment during and for some time after welding or cutting if:
a) appreciable combustibles (including building construction) are within 10m.
b) appreciable combustibles are further than 10m but can be ignited by sparks.
c) openings (concealed or visible) in floors or walls within 10m can expose
combustibles to sparks.
d) combustibles adjacent to walls, ceilings, roofs or metal partitions can be
ignited by radiant or conducted heat.
After work is done, check that area is free of sparks, glowing embers, and flames.
An empty container that held combustibles, or that can produce flammable or
toxic vapours when heated, must never be welded on or cut, unless container
has first been cleaned. This includes.......a thorough steam or caustic cleaning (or
a solvent or water washing, depending on the combustible’s solubility) followed
by purging and inerting with nitrogen or carbon dioxide, and using protective
equipment.
Water filling just below working level may substitute for inerting.
A container with unknown contents should be cleaned (see paragraph above),
do NOT depend on sense of smell or sight to determine if it is safe to weld or cut.
Hollow castings or containers must be vented before welding or cutting - they
can explode.
In explosive atmospheres, never weld or cut where the air may contain flammable
dust, gas, or liquid vapours.
22
No. Description Qty Part No. Part No.
1 Input Cable ........................................... 1 EM20220014 EM20220014
2 Green Pilot-light Switch 16a-250v ....... 1 EM22200002 EM22200002
3 Upper Panel .......................................... 1 EM33705220 EM33705220
4 Belt Regulator ....................................... 1 EM21600024 EM21600024
5 Cable Clamp ........................................ 1 EM21605009 EM21605009
6 Potentiometer Knob ............................ 1 EM21690127 EM21690127
7 Module For Inverter .............................. 1 EM42735015 EM42735016
8 Lower/Back Panel ................................ 1 EM33700139 EM33700139
9 Din Plug ................................................. 2 EM22100002 EM22100002
No. Description Qty Part No.
1 Input Cable ................................................................... 1 EM20220014
2 Complete Fan .............................................................. 1 EM22800021
3 Choke Winding Inverter............................................... 1 EM44035052
4 Cable Clamp ................................................................ 1 EM21605010
5 Plastic Vent .................................................................... 1 EM21690287
6 Cover Panel .................................................................. 1 EM33705335
7 Potentiometer 10k ........................................................ 1 EM26086008
8 Dividing Panel ............................................................... 1 EM33620104
9 Feet ................................................................................ 2 EM21610019
10 Transformer 230v .......................................................... 1 EM44155027
11 On/Off Switch 16a-250v .............................................. 1 EM22200002
12 Rear Panel ..................................................................... 1 EM33700180
13 Plastic Abat-vent .......................................................... 1 EM21690286
14 Female Dinse Plug ........................................................ 2 EM22100002
15 Coupling For Belt .......................................................... 2 EM21690117
16 Belt For Inverter ............................................................. 1 EM21600023
17 Complete Inverter P.c.board ...................................... 1 EM42735020
18 Front Panel .................................................................... 1 EM33710250
19 Potentiometer Knob .................................................... 1 EM21690288
PARTS LISTS
TIG90 & TIG115
TIG150

8
2. ELECTRIC ARC (MIG, TIG) WELDING
Comply with precautions in 1 above, and this section. Arc welding, properly done,
is a safe process, but a careless operator invites trouble. The equipment carries
high currents at significant voltages. The arc is very bright and hot. Sparks fly,
fumes rise, ultraviolet and infrared energy radiates, weldments are hot. The wise
operator avoids unnecessary risks and protects himself and others from accidents.
2A) BURN PROTECTION
Comply with precautions in 2. The welding arc is intense and visibly bright. Its
radiation can damage eyes, penetrate lightweight clothing, reflect from light
coloured surfaces, and burn the skin and eyes. Skin burns resemble acute sunburn,
those from gas - shielded arcs are more severe and painful.
DON’T GET BURNED! COMPLY WITH PRECAUTIONS!
1) Protective clothing
Wear long sleeved clothing (particularly for gas shielded arc) in addition to
gloves, hat and shoes (2A). As necessary, use additional protective clothing
such as leather jacket or sleeves, flameproof apron, and fire-resistant leggings.
Avoid outer garments of untreated cotton. Bare skin protection. Wear dark
substantial clothing. Button collar to protect chest and neck and button
pockets to prevent entry of sparks.
2) Eye and head protection
Protect eyes from exposure to arc. NEVER look at an electric arc without
protection. Welding helmet or shield containing a filter plate shade no. 12 or
denser must be used when welding. Place over face before striking arc. Protect
filter plate with a clear cover plate. Cracked or broken helmet or shield should
NOT be worn; radiation can pass through to cause burns. Cracked, broken,
or loose filter plates must be replaced IMMEDIATELY. Replace clear cover plate
when broken, pitted, or spattered. WE SUGGEST you wear flash goggles with
side shields under the helmet, to give some protection to the eyes should the
helmet not be lowered over the face before an arc is struck. Looking at an
arc momentarily with unprotected eyes (particularly a high intensity
gas-shielded arc) can cause a retinal burn that may leave a permanent dark
area in the field of vision. Before welding whilst wearing contact lenses, seek
advice from your optician.
3) Protection of nearby personnel
For production welding, a separate room or enclosed bay is best.
In open areas, surround the operation with low reflective, non- combustible
screens or panels. Allow for free air circulation, particularly at floor level. Provide
face shields for all persons who will be looking directly at the weld. Others
working in the area should wear flash goggles. Before starting to weld, make
sure that screen or bay doors are closed.
21
ACCESSORIES
1. ARC WELDING kit, Part No. 6010810 (Arc/Tig 90 & 120)
Part No. 6010825 (Arc/TIG 150)
comprising 1. Electrode Holder with cables
2. Work Clamp with cable
3. Head shield
4. Wire Brush with pick
2. TIG WELDING kit Part No. 6010800
comprising 1. TIG Torch w/hose
2. Gas Regulator Assembly
3. Work Clamp with cable
SPECIFICATIONS
Arc/TIG90 Arc/TIG120 Arc/TIG 150
Power Supply 230V 50Hz 1Ph 230V 50Hz 1Ph 230V 50Hz 1Ph
Max. Input Current 13A 17.5A 24A
Open Circuit Voltage 51V 50V 92V
Protection Class. IP21 IP21 IP21
Insulating Class. H H H
Min/Max. Welding Current 20/90A 20/110A 15/130A
Useable Electrodes 1.6 - 2.5mm Dia. 1.6 - 2.5mm Dia. 1.6 - 3.2mm Dia.
Dimensions 270x115x200 270x115x200 350x140x255
Weight 4kg 6kg 6.5kg
Part No. 6012130 6012140 6012160
Duty Cycle Welding Current Welding Current Welding Current
35% 70Amps 100Amps 130Amps
60% 50Amps 70Amps 100Amps
100% 40Amps 60Amps 80Amps
eg. With a TIG 120 machine, you may weld at 100 Amps for 3.5 minutes (35%) in a 10 min.
cycle, or for 6 minutes at 70 Amps.
Please note that the details and specifications contained herein, are correct at the time of going to print. However,
CLARKE International reserve the right to change specifications at any time without prior notice.
ALWAYS read the data label

9
2B) TOXIC FUME PREVENTION
Comply with precautions in 2-B. Generator engine exhaust must be vented to the
outside air. Carbon monoxide can kill.
2C) FIRE AND EXPLOSION PREVENTION
Comply with precautions in 2-C. Equipment’s rated capacity. Do not overload
arc welding equipment. It may overheat cables and cause a fire. Loose cable
connections may overheat or flash and cause a fire. Never strike an arc on a
cylinder or other pressure vessel. It creates a brittle area that can cause a violent
rupture or lead to such a rupture later under rough handling.
2D) SHOCK PREVENTION
Exposed live conductors or other bare metal in the welding circuit, or in unearthed,
electrically-LIVE equipment can fatally shock a person whose body becomes a
conductor. DO NOT STAND, SIT, LIE, LEAN ON, OR TOUCH a wet surface when
welding, without suitable protection.
2E) PROTECTION FOR WEARERS OF ELECTRONIC LIFE SUPPORT DEVICES (PACEMAKERS)
Magnetic fields from high currents can affect pacemaker operation. Persons
wearing electronic life support equipment (pacemaker) should consult with their
doctor before going near arc welding, gouging, or spot welding operations.
2F) TO PROTECT AGAINST SHOCK:
Keep body and clothing dry. Never work in damp area without adequate insulation
against electrical shock. Stay on a dry duckboard, or rubber mat when dampness
or sweat can not be avoided. Sweat, sea water, or moisture between body and
an electrically LIVE part - or earthed metal - reduces the body surface electrical
resistance, enabling dangerous and possibly lethal currents to flow through the
body.
1) Earthing the equipment
When arc welding equipment is earthed according to the National Electrical
Code, and the work is earthed, a voltage may exist between the electrode
and any conducting object.
Examples of conducting objects include, but are not limited to, buildings,
electrical tools, work benches, welding power source cases, workpieces, etc.
Never touch the electrode and any metal object unless the welding power
source is off. When installing, connect the frames of each unit such as welding
power source, control, work table, and water circulator to the building earth.
Conductors must be adequate to carry earth currents safely. Equipment made
electrically LIVE by stray current may shock, possibly fatally. Do NOT EARTH to
electrical conduit, or to a pipe carrying ANY gas or a flammable liquid such
as oil or fuel.
TIG WELDING
WELDING WORKPIECE FILLER WELDING GAS
METAL CURRENT THICKNESS ROD ELECTRODE FLOW
(Amps) (mm) Dia (mm) Dia (mm) Ltr/min
30 1 0-2 1.6 4
Mild 70 2 2.0 1.6 4
Steel 115 3 2.4 2.4 4.3
140 4 2.4 2.4 4.6
35 1 0-2 1.6 4
Stainless 80 2 2.4 2.4 4.3
Steel 130 3 2.4 2.4 4.6
160 4 2.4 2.4 5
Copper 80 2 2.4 2.4 5
130 3 3.2 2.4 5
Always ensure that the gas is turned OFF at the cylinder after use.
MAINTENANCE
The ARC/TIG Inverter, requires very little maintenance other than the guidelines
shown below. Under normal working conditions removing the covers and cleaning
with dry compressed air at reduced pressure once a year will be quite sufficient.
Cleaning at more frequent intervals is advisable however, if the unit is operating in
a dusty and dirty environment.
1. Keep the louvres clean to avoid a build up of dirt and oxides inside the
machine, which can reduce machine output.
2 Check all cables periodically: They must be in good condition and not
cracked.
3. Always try to avoid getting particles of metal inside the machine since they
could cause short circuits.
IMPORTANT - Disconnect from mains before cleaning.
20

10
2) Electrode holders
Fully insulated electrode holders should be used. Do NOT use holders with
protruding screws or with any form of damage.
3) Connectors
Fully insulated lock-type connectors should be used to join welding cable.
4) Cables
Frequently inspect cables for wear, cracks and damage. IMMEDIATELY
REPLACE those with excessively worn or damaged insulation to avoid
possibly lethal shock from bared cable. Cables with damaged areas may
be taped to give resistance equivalent to original cable. Keep cable dry,
free of oil and grease, and protected from hot metal and sparks.
5) Terminals and other exposed parts
Terminals and other exposed parts of electrical units should have insulating
covers secured before operation.
6) Electrode
a) Equipment with output on/off control (contactor)
Welding power sources for use with the gas metal arc welding, gas
tungsten arc welding and similar processes normally are equipped with
devices hat permit on/off control of the welding power output. When
so equipped the electrode wire becomes electrically LIVE when the
power source switch is ON and welding gun switch is closed. Never
touch the electrode wire or any conducting object in contact with
the electrode circuit unless the welding power source is off.
b) Equipment without output on/off control (no contactor)
Welding power sources used with shielded metal arc welding and similar
processes may not be equipped with welding power output on/off
control devices. With such equipment the electrode is electrically LIVE
when the power switch is turned ON. Never touch the electrode unless
the welding power source is off.
7) Safety devices
Safety devices such as interlocks and circuit breakers should not be
disconnected or shunted out. Before installation, inspection, or service of
equipment,shut OFF all power and remove line fuses (or lock or red-tag
switches) to prevent accidental turning ON of power. Do not open power
circuit or change polarity while welding. If, in an emergency, it must be
disconnected, guard against shock burns, or flash from switch arcing.
Always shut OFF and disconnect all power to equipment. Power disconnect
switch must be available near the welding power source.
Scratch the tip of the electrode on soon as an arc develops, quickly withdraw
the electrode to maintain a gap of approx. 3-4 mm, and proceed to weld.
(See notes below).
To stop welding, simply remove the torch from the workpiece.
This method is referred to as ‘Scratch Arc’.
REMEMBER to turn OFF the gas immediately you finish welding.
NOTES:
a) To avoid a visible strike mark on the surface of the workpiece, it is advisable to
strike the arc in the joint, where the mark will be concealed by the weld.
b) Thin sheet and stainless steel may be welded with or without filler, similar to
gas welding.
The filler is fed in at the edge of the pool. The rod must not touch the tip of the
electrode or enter the arc. The end of the rod must always be shielded by the
argon atmosphere to prevent as far as possible the formation of oxides of its
surface. When welding stainless steel and copper, it is often possible to feed
in the filler continuously at the edge of the pool.
c) The arc length generally varies between 3 and 6mm. depending on the type
of joint, type and thickness of material, and so on.
d) The torch is advanced in the direction of welding, without lateral movement,
maintaining the torch angle of 450to the workpiece.
Guidelines for the TIG welding current needed and recommended electrode sizes
etc. for different gauges of material are shown in the chart on the following page:
19

11
PREPARATION OF THE WORKING AREA
The working area must be sufficiently spacious, not humid, and well-ventilated as
to avoid any fumes which develop from the welding process and from incidental
material adhering to the pieces to be welded (oils, paints, tars...) which may cause
annoyance to the operator.
Avoid welding by contact with humid parts nearby combustible liquids. Least of
all, do not weld upon tanks which may contain inflammable residuals.
SAFETY EQUIPMENT
A comprehensive range of CLARKE safety equipment for use when welding is
available from your local CLARKE dealer.
SAFETY PRECAUTIONS for ARC/TIG WELDING
✔ALWAYS ensure that there is full free air circulating around the outer casing of
the machine, and that the louvres are unobstructed.
✔Welding arc can seriously damage your eyes. Both operator and spectators
must ALWAYS use a proper welding face shield or helmet, with suitable filter
lenses. Proper gloves and working clothes should be worn at all times.
✔ALWAYS check that the pressure regulator and gauges are working correctly.
DO NOT lubricate the regulator.
✔ALWAYS use the correct regulator. Each regulator is designed to be used with
a specific gas.
✔ALWAYS inspect the hose before use to ensure it is in good condition.
✔ALWAYS keep the free length of gas hose outside the work area.
✔ALWAYS remove all flammable materials from the welding area.
✗NEVER remove any of the panels unless the machine is disconnected from
the supply, AND never use the machine with any of the panels removed.
✗NEVER attempt any electrical or mechanical repair unless your are a qualified
technician. If you have a problem with the machine contact your local
CLARKE dealer.
Additionally, before preparing for Tig welding, you must procure a large gas
cylinder of 100% pure Argon.
To prepare the unit for TIG welding, it is important that you adopt the following
procedure.
1. Plug the work return lead in to the +ve terminal, and secure the work clamp to
the workpiece.
For good contact, the work clamp must be attached to clean bare metal.
Clean with a wire brush where necessary
2. Plug the Torch lead to the -ve terminal
3. Screw the pressure regulator on to
the gas bottle tightly, and attach
the gas hose to the inlet connector
securely, with a hose clip. Screw in
the pressure regulator knob to set
a pressure of approx. 2,5Kg./cm2.
(35 lbf/in2).
4. Ensure the electrode at the torch
nozzle,protrudes by 4 - 5mm., also
ensure that the electrode is sharply
pointed withan angle of 40°-60°, if
it is not, grind it longitudinally.
(Consult your TIG Torch manual for
the procedure for adjusting the
electrode).
5. Set the welding current in
accordance with the thickness of
the material to be welded and the
size of tungsten electrode to be
used, (see chart on page 20), and
switch ON using the switch mounted
on the rear panel. The green light
on the front panel will glow.
6. Open the gas valve on the torch handle, allowing gas to flow from the
Fig 3
Fig 2
torch nozzle. Cover your
face with the head shield,
bring the torch to within 3-
4mm of the work, and at
an angle of 45°, so that
the ceramic nozzle gently
touches the work
surface. See fig. 3.
18

✗NEVER use or store in a wet/damp environment. DO NOT EXPOSE TO RAIN.
✗The Tig welding process uses an INERT gas to protect the weld pool. It is
important to ensure the appropriate gas is being used. NEVER use gas from
a cylinder, the content of which is unknown.
✗NEVER a. Use a damaged cylinder.
b. Lift the cylinder by the valve.
c. Expose the cylinder to a heat source or sparks.
✗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.
✗NEVER use the Welder with input connections greater than 10M in length.
✗NEVER point the TIG torch at any person or animal.
✗NEVER touch the TIG torch nozzle until the welder is switched OFF and the
nozzle has been allowed to cool off.
✗NEVER connect, disconnect, or attempt to service the TIG torch, until the
machine is switched OFF and disconnected from the mains supply.
✗NEVER allow the cables to become wrapped around the operator or any
person in the vicinity.
ADDITIONAL PRECAUTIONARY MEASURES
IMPORTANT:
The TIG machine generates both airborne and line interference due to the high
frequencies involved. It is important not to locate electronic or electrically sensitive
equipment in the vicinity of the welder or alternatively, do not locate the welder
in vicinity of electronic or electrically sensitive equipment.
12 17
Note: If the machine stops at any time and the amber light comes ON the
thermal overload has intervened
5. The most difficult aspect of the arc welding process, particularly for beginners,
is that of striking an arc. We strongly recommend that you practice on some
pieces of scrap metal to get the feel of the operation, before you start on an
actual welding job.
6. Hold the electrode about 10mm. from the work and at an angle of about
70°to 80°to the work surface; take care not to accidentally touch the workpiece
until you are ready to commence.
7. Holding the welding mask close-up to the face, give a short stroke with the
electrode on the workpiece. As soon as the arc is primed, withdraw the
electrode from the workpiece to leave a tiny gap of around 1.5mm (1/16").
The current will flow across the gap with a crackling noise and brilliant arc.
Continue to weld in one direction, maintaining the small gap as you go. At
the end of the run just withdraw the electrode fully from the workpiece.
Note: When you prime the arc be sure to withdraw the electrode fairly swiftly
to leave the 1.5mm. gap, otherwise the electrode will weld itself to the
workpiece. Should this occur give the electrode a short sharp jerk to free it
and, if necessary prime the arc again. If you cannot free the electrode, switch
the machine off immediately, and free it off.
8. Inspect the job carefully. With a correct combination of rod size and current
setting, the area of the weld should be a complete fusion of the electrode
metal with the metals being joined. Slag forming on the surface should be
chipped away with a chipping hammer or pick. ALWAYS wear your safety
goggles when chipping away slag.
NOTE: If the resultant weld looks irregular or messy, or shows signs of porosity
or slag contamination, you have almost certainly failed to achieve the correct
combination, (or dirt /oil is present on workpiece). Do not worry as practice
will soon cure this.
HEALTH WARNING:
When welding always ensure there is adequate ventilation in the
work area as the welding process gives off toxic fumes.
B. TIG WELDING (Refer to Fig.2)
The machine is not equipped with a TIG welding torch and cables. We recommend
the use of our TIG WELDING KIT, Model TK1 (Part No. 6010800), which is designed
specifically for use with this equipment, and is available from your CLARKE dealer.

13
PRINCIPLES OF OPERATION
The ARC/TIG welder, as its name suggests, is designed to be used for both Metal
ARC, AND TIG welding. To accomplish this, two sets of welding leads are required,
one for each method employed.
Welding leads are not supplied with the machine. These are readily available
from your CLARKE dealer. Please refer to ‘Accessories’ on page 21 for details.
1. ARC WELDING.
Shielded Metal Arc welding is by far the most widely used of the various arc welding
processes. It employs the heat of the arc to melt the base metal and the tip of a
consumable flux covered electrode.
The electrode and the workpiece are part of an electric circuit. This circuit begins
with the electric power source and includes the welding cables, an electrode
holder, a workpiece connection, the workpiece, and an arc welding electrode.
One of the two cables from the power source is attached to the work. The other
is attached to the electrode holder.
Welding commences when an electric arc is struck between the tip of the
electrode and the work. The intense heat of the arc melts the tip of the electrode
and the surface of the work close to the arc. Tiny globules of molten metal rapidly
form on the tip of the electrode, then transfer through the arc stream into the
molten weld pool. In this manner, filler metal is deposited as the electrode is
progressively consumed.
The arc is moved over the work at an appropriate arc length and travel speed,
melting and fusing a portion of the base metal and continuously adding filler metal.
Since the arc is one of the hottest of the commercial sources of heat (temperatures
above 90000F (50000C) have been measured at its centre), melting of the base
metal takes place almost instantaneously upon arc initiation.
If welds are made in either the flat or the horizontal position, metal transfer is induced
by the force of gravity, gas expansion, electric and electromagnetic forces, and
surface tension. For welds in other positions, gravity works against the other forces.
The process requires sufficient electric current to melt both the electrode and a proper
amount of base metal. It also requires an appropriate gap between the tip of the
electrode and the base metal or the molten weld pool. These requirements are necessary
to set the stage for coalescence.
The sizes and types of electrodes for shielded metal arc welding define the arc voltage
requirements (within the overall range of 16 to 40V) and the current requirements (within
the overall range of 20 to 550A). The current may be either alternating or direct, depending
upon the electrode being used, but the power source must be able to control the level
of current within a reasonable range in order to respond to the complex variables of the
welding process itself.
16
A. ARC WELDING (Refer to Fig 1.)
Arc welding cables are not supplied with this machine. We recommend the use of
CLARKE ARC WELDING KIT, which is available from your CLARKE dealer, and is designed
specifically for this machine.
The kit comprises all necessary cables, plus a hand shield and wire brush with chipping
pick.
To prepare the unit for ARC welding, it is
important that you follow the procedure
below.
1. With the ON/OFF switch, located on the rear
panel, in the OFF position, connect the
welding leads as follows:
Welding Electrode lead to the +ve terminal
Work Clamp lead to the -ve terminal.
2. Attach the work clamp to the workpiece
- as close as possible to the area being
welded. Clean with a wire brush where
necessary to ensure the connection is as
clean as possible.
3. An appropriate current must then be set by
turning the Welding Current Selector located
on the front panel of the machine. With
practice you will gain a feel for the correct
current setting for different welding rod
thicknesses.
The size (diameter) of welding rod should
be approximately the same as the thickness of metal to be welded.
For beginners, the following table gives some useful guidelines.
SIZE OF THICKNESS CURRENT
WELDING ROD OF WORKPIECE SETTING (AMPS)
1.5mm 16 SWG - 1.5 MM. 30 - 40
2.0mm 14 SWG - 2.0 MM. 50 - 65
2.5mm 12 SWG - 2.5 MM. 70 - 100
3.0mm 10 SWG - 3.25MM 100 - 130
4. Switch ON using the switch located on the rear panel. The green light on the
front panel should glow, indicating the machine is ON.
WELDING TECHNIQUES
Fig 1

2. TIG WELDING
TIG welding Is primarily a DC current process, but can also utilise AC, usually for
very thin materials and when welding Aluminium or other non ferrous metals. It
uses a non-consumable tungsten (or tungsten alloy) electrode, held in a torch.
Shielding gas (100% Argon), is fed through the torch to protect
a. the electrode,
b. molten weld pool,
and c. solidifying weld metal........ from contamination by the atmosphere.
The electric arc is produced by the passage of current through the conductive,
ionized shielding gas. The arc is established between the tip of the electrode and
the work. Heat generated by the arc melts the base metal. Once the arc and
weld pool are established, the torch is moved along the joint and the arc
progressively melts the joined surfaces. Filler wire, if used, is usually added to the
leading edge of the weld pool to fill the joint.
This process is ideally suited for welding thin metals, pressure vessels, heat
exchangers, pipes etc., where accuracy and a high quality weld is desired, as it
produces a very low porosity weld.
Tig Welding Process Advantages
• It produces superior quality welds, generally free of defects.
• It is free of the spatter which occurs with other arc welding processes.
• It can be used with or without filler metal as required for the specific
application.
• It allows excellent control of root pass weld penetration.
• It can produce inexpensive autogenous welds at high speeds.
• It can use relatively inexpensive power supplies.
• It allows precise control of the welding variables.
• Welds all metals
• Capable of welding very thin material (0.5mm), without undue distortion.
Main Features of Tig Welding
1. Welds all metals.
2. Electronic control of welding current.
3. Forced air cooling.
4. A Thermal Overload Protection Device prevents overheating the transformer.
Limitations
1. Greater weld dexterity is required
2. It is more expensive to weld thicker materials - greater than 4 - 5mm
14 15
WARNING! THIS APPLIANCE MUST BE EARTHED.
a. Arc/TIG90
Connect the power cable directly to suitably fused, 230 volt (50Hz) domestic
electrical supply or to a standard 13 amp BS 1363 plug, fitted with a 13 amp fuse. We
strongly recommend that this be done via a Residual Current Device (RCD).
Fuse Rating
The fuse in the plug must be replaced with one of the same rating (13 amps) and
this replacement must be ASTA approved to BS1362.
b. Arc/TIG’s 120 & 150
Connect the mains lead, through a suitably fused isolator switch, to a 230 Volt
(50Hz) electrical supply, with a fuse rating in accordance with the specifications
shown on page 21. A standard 13 Amp plug MUST NOT be used with these welders.
c. ALL MODELS
IMPORTANT: The wires in the mains lead are coloured in accordance with the
following code:
Green & Yellow .......... Earth
Blue .......... Neutral
Brown .......... Live
As the colours of the flexible cord of this appliance may not correspond with the
coloured markings identifying terminals in your plug, proceed as follows:
•Connect GREEN & YELLOW cord to plug terminal marked with a letter “E” or
Earth symbol “ ”, or coloured GREEN or GREEN & YELLOW.
•Connect BROWN cord to plug terminal marked letter “L” or coloured RED.
•Connect BLUE cord to plug terminal marked letter “N” or coloured BLACK.
Extension Cable
If an extension cable is fitted, ensure the minimum cross section of the conductor
is 1.5mm2for up to 15 metres in length, and 2.5mm2for up to 25 metres.
ELECTRICAL CONNECTIONS