Kemppi MINARC 120 User manual

Operation instructions • english
Gebrauchsanweisung • deutsch
Gebruiksaanwijzing • nederlands
Manuel d’utilisation • français
1910150AU
0546
MINARC
120, 150

© KEMPPI OY2 – MINARC 120, 150 / 0546
CONTENTS
1. PREFACE ...................................................................................................................... 3
1.1. INTRODUCTION ......................................................................................................... 3
1.2. PRODUCT INTRODUCTION ...................................................................................... 3
1.3. OPERATION SAFETY ................................................................................................. 3
2. BEFORE YOU START USING THE UNIT .................................................................... 4
2.1. UNPACKING ............................................................................................................... 4
2.2. PLACING THE UNIT ................................................................................................... 4
2.3. SERIAL NUMBER ....................................................................................................... 4
2.4. MAIN COMPONENTS ................................................................................................. 4
2.5. CONNECTING TO POWER SUPPLY MAINS ............................................................. 5
2.6. FILLER MATERIALS AND EQUIPMENT .................................................................... 5
3. USE  5
3.1. WELDING PROCESSES ............................................................................................ 5
3.1.1. MANUAL METAL ARC WELDING (MMA) ...................................................... 5
3.1.2. TIG WELDING ................................................................................................ 6
3.2. OPERATING FUNCTIONS .......................................................................................... 6
3.3. WELDING SELECTIONS ............................................................................................ 6
3.3.1. MANUAL METAL ARC WELDING (MMA) ...................................................... 6
3.3.2. DC TIG WELDING ......................................................................................... 7
3.4. WELDING .................................................................................................................... 7
3.4.1. EARTHING ..................................................................................................... 7
3.4.2. WELDING ...................................................................................................... 7
3.5. STORING .................................................................................................................... 7
4. MAINTENANCE ............................................................................................................. 7
4.1. DAILY MAINTENANCE ............................................................................................... 8
4.2. TROUBLESHOOTING ................................................................................................ 8
5. ORDERING NUMBERS ................................................................................................. 8
6. TECHNICAL INFORMATION ......................................................................................... 9
7. DISPOSAL OF THE MACHINE ................................................................................... 10
8. TERMS OF GUARANTEE ........................................................................................... 10

© KEMPPI OY MINARC 120, 150 / 0546 – 3
1. PREFACE
1.1. INTRODUCTION
Congratulations on having purchased a KEMPPI product. Properly installed and used KEMPPI
products should prove to be productive machines requiring only a small amount of regular
maintenance.
This manual is arranged to give you a good understanding of the equipment and its safe use. There
is also information on both servicing the unit as well as its technical data. Read the instructions
before taking the machine into use or servicing it for the first time. Additional information on
Kemppi products and their use can be obtained from Kemppi or a Kemppi dealer.
The specifications and designs presented in this manual are subject to change without prior
notice.
In this document, for danger to life or injury the following symbol is used:
Read the warnings carefully and follow the instructions. Please also study the operation safety
instructions and respect them when installing, operating and servicing the machine.
1.2. PRODUCT INTRODUCTION
Kemppi Minarc 120, 150 is a Manual Metal Arc welding machine, small in size, suitable for
industry, site and repair welding. The unit uses one phase connection voltage.
Minarc 120, 150 is equipped with so called Voltage Reduction Device (VRD) function to avoid
danger of electric shock. VRD maintains open circuit voltage under 35 V.
Minarc tolerates a great fluctuation of input voltage and is thus suitable for work on sites using
generator as well as to be used with long power cables. Inverter technology has been used when
designing the unit. Power regulation in power source is done with IGBT transistors. Welding and
earth cables are supplied with the unit. They are equipped with suitable electrode holder, earth
clamps and connections for the unit.
Minarc can also be used for TIG welding. TIG arc is started by scratching. Ordering numbers of
additional equipment for TIG welding can be found under 5. Ordering numbers.
1.3. OPERATION SAFETY
Read the warning texts carefully and follow the instructions.
Arc and welding spatter
Arc and the reflected radiation from it can damage unprotected eyes. Shield your eyes and protect
your surroundings appropriately before you start welding. Arc and welding spatter will burn
unprotected skin. When welding, use protective gloves and clothing.
Danger of fire and explosion
Observe the fire safety instructions. Remove flammable material around the place where you will
weld. Have necessary fire extinguishing equipment at hand when you weld. Note dangers caused
by special jobs, such as risk of fire and explosion when welding tanks. Note! Sparks may ignite
fire even hours later!
Welding is working with fire, note special instructions for such work.
Mains voltage
Never take welding machine inside the work piece (e.g. container or car). Never set the welding
machine on wet surface. Replace faulty cables immediately, they create a danger to life and can
cause a fire. See that the connecting cable does not stick nor touch sharp edges or a hot welding
piece.

© KEMPPI OY4 – MINARC 120, 150 / 0546
Welding current circuit
Isolate yourself from the welding current circuit by wearing dry and undamaged protective clothing.
Never work on a wet surface. Never use damaged welding cables. Never set neither electrode holder,
earth clamp nor the welding cables on top of the power source or other electric equipment.
Welding fumes
Ensure adequate ventilation. Always take special measures when welding metals containing lead,
cadmium, zinc, mercury or beryllium.
2. BEFORE YOU START USING THE UNIT
2.1. UNPACKING
The unit is packed in durable packages, designed specially for it. Nevertheless, always before
using the unit, make sure it was not damaged during transportation. Also check that you have
received what you ordered and that there are instructions for it. NOTE! The packaging material of
the products is suitable for recycling.
2.2. PLACING THE UNIT
Place the unit on horizontal, solid and clean surface. Shield it from heavy rain and scorching sun.
Make sure that cooling air circulates freely.
2.3. SERIAL NUMBER
Serial number of the unit is marked on the rating plate of the unit. The serial number makes it
possible to trace product manufacturing series. You might need the serial number when placing
spare parts orders or when planning maintenance.
2.4. MAIN COMPONENTS
Connect welding cable and earth cable to their connections on the power source. Mains cable and
wall plug are already installed.

© KEMPPI OY MINARC 120, 150 / 0546 – 5
Parts of the unit
A Body of machine
B Main power switch and signal light
C Selector switch for welding process
D Welding current regulator
E Signal light VRD safe ON
F Signal light for overheating
G Electrode holder and welding cable
H Earth cable and clamp
2.5. CONNECTING TO POWER SUPPLY MAINS
The unit has a mains cable and a wall plug. You can find fuse and cable sizes in the end of these
instructions in Technical data.
2.6. FILLER MATERIALS AND EQUIPMENT
See also 2.4. Main components. You can use all electrodes intended for welding with DC. Suitable
electrode sizes for the unit are listed in the table on unit’s front panel as well as in the end of these
instructions in Technical data.
1. Use welding specifications given on electrode package.
2. Check that you have selected the correct welding process before starting to weld.
3. Check that welding cable and earth cable connections are tight. If a connection is slack, it
will result in voltage drop that will cause the connection to heat.
4. Mount the electrode firmly in holder.
3. USE
It is forbidden to weld in places where there is a danger of fire or explosion!
3.1. WELDING PROCESSES
3.1.1. Manual Metal Arc welding (MMA)
In manual metal arc (MMA) the welding filler material is melted from the electrode to the weld
pool. Filler and rate of welding current is selected on the basis of electrode size used and welding
position. Arc is formed between electrode tip and work piece. The melting electrode coating forms
gas and slag, which protects the weld pool. Slag solidified over the weld is removed after welding
e.g. with a chipping hammer.
A
H
B
C
D
E
G
F
-
+

© KEMPPI OY6 – MINARC 120, 150 / 0546
3.1.2. TIG welding
In DC TIG welding, the arc between a non-melting tungsten electrode and the work piece melts
the work piece, thus forming a weld pool. Arc and electrode are shielded by an inert shielding gas
(Argon). If necessary, filler can be used. Filler wire is fed into the weld pool from the outside of the
arc. Filler and rate of welding current are selected on the basis of diameter of tungsten electrode
and welding position.
3.2. OPERATING FUNCTIONS
See also 2.4. Main components and 3.4. Welding selections.
A Signal light VRD safe ON
B Welding process selecting switch
C Welding current regulator
D Signal light for overheating
E Table of suitable electrodes
Main switch and signal light
When you switch the main switch at the back of
machine to position I, signal light on main switch is
lit and the unit is ready for welding. Signal light is
always on when the unit is connected to the mains
and the main switch is in position I.
Note! Always start and stop the machine from the main switch, never use the plug as a switch!
Signal light VRD safe ON (A)
The machine is equipped with an OCV reduction circuit. The signal light is lit when the circuit is
activated and the unit is in working order.
Welding process selector, MMA / TIG (B)
Switch is used for selecting either MMA or TIG welding, depending on welding target. When you
have switched the unit to TIG welding, VRD is constantly active, thus reducing terminal voltage
to 30 V. This facilitates arc cut-off when you stop welding.
Regulating the welding current (C)
Welding current rate is regulated steplessly with an adjusting potentiometer.
Signal light for overheating (D)
A yellow signal light for overheating is lit when thermostat has tripped due to the unit’s overheating.
Fan will cool the unit and after the signal light goes off, the unit is again ready for welding.
3.3. WELDING SELECTIONS
3.3.1. Manual Metal Arc welding (MMA)
Select welding parameters according to filler manufacturer’s recommendations.
1. Select polarity (+ or -) of welding current cable and return current cable according to
filler.
2. Select MMA welding with the switch .
3. Select suitable welding current by adjusting the potentiometer according to table of suitable
electrodes (E).
B
C
E
A
D

© KEMPPI OY MINARC 120, 150 / 0546 – 7
3.3.2. DC TIG welding
Select welding parameters according to filler manufacturer’s recommendations.
1. Connect TIG torch to - pole and earth cable to + pole
2. Select TIG welding with switch .
3. Select suitable welding current by adjusting the potentiometer.
3.4. WELDING
Welding fumes may be dangerous for your health, see that there is ample ventilation
during welding!
Never look at the arc without face shield made for arc welding! Protect yourself and
your surroundings from the arc and hot spatter!
3.4.1. Earthing
If possible, always fix earth cable clamp directly on the work piece.
1. Clean connection surface of earth clamp from paint and rust.
2. Connect the clamp carefully so that contact surface is as large as possible.
3. Finally check that the clamp sits tight.
3.4.2. Welding
See also 3.1. Welding processes and 3.3. Welding selections. Note! It is recommended that you try
welding and rate of welding current first on something else than the actual work piece.
You can start welding after having made the necessary selections. Arc is lit by scratching the welding
piece with electrode. Arc length is regulated by holding electrode tip at a suitable distance from
work piece. Suitable arc length is usually about half the diameter of the electrode core wire. When
arc is lit, move the electrode slowly forwards tilting it to appr. 10-15° pulling angle. If necessary,
adjust the current value.
Shielding gas is used in DC TIG welding. Your dealer will give you advice on choosing the gas and
equipment. Open the gas valve on the TTM 15V TIG torch. When gas starts to flow, arc is lit by
lightly scratching the work piece with the tip of the tungsten electrode. When arc is lit, its length
is regulated by holding the tip of the tungsten electrode at a suitable distance from the work piece.
Move the torch forwards from the starting point, usually in appr. 10-15° pushing angle forwards.
If necessary, regulate the current rate. Stop welding by lifting the torch off the work piece and by
closing the gas valve on the torch.
Note! Always fix the gas cylinder so that it stays steadily in upright position either in specially made
wall rack or cylinder trolley. Always close the cylinder valve after having finished welding.
3.5. STORING
Store the unit in a clean and dry place. Shield it from rain, and in temperatures exceeding +25 °C
from direct exposure to sun.
4. MAINTENANCE
Be careful when handling electric cables!
In maintenance of the unit, take into consideration the rate of use and the environment it is used
in. When the unit is used properly and serviced regularly, you will avoid unnecessary disturbances
in use and production.

© KEMPPI OY8 – MINARC 120, 150 / 0546
4.1. DAILY MAINTENANCE
Perform the following maintenance daily:
– Clean electrode holder and TIG torch’s gas nozzle. Replace damaged or worn parts.
– Check TIG torch’s electrode. Replace or sharpen, if necessary.
– Check tightness of welding and earth cable connections.
– Check condition of mains and welding cables and replace damaged cables.
– See that there is enough space in front of and back of the unit for ventilation.
4.2. TROUBLESHOOTING
Main switch signal light is not lit.
Unit does not get electricity.
– Check mains fuses and replace if necessary.
– Check mains cable and plug, replace damaged parts.
Unit does not weld well.
Arc is uneven and goes off. Electrode gets stuck in weld pool.
– Check welding settings and adjust when necessary. See 3. Use.
– Check that earth clamp is properly fixed and that contact surface is clean and the cable is
undamaged. See 3.4. Welding and 4.1. Daily maintenance.
Signal light for overheating is lit.
The unit has overheated. See 3.2. Operating functions.
– Check that there is ample space in front of and back of the unit for ventilation.
– Check welding settings. See 3.3. Welding selections.
If problems in use are not solved with above mentioned measures, please contact a Kemppi service
workshop.
5. ORDERING NUMBERS
Item Ordering number
Minarc 120 welding machine 6102120AU
Minarc 150 welding machine 6102150AU
(includes earth- and welding cables)
Earth cable and clamp 6184015
Welding cable and electrode holder 6184005
Carrying strap 9592162
Optional:
TIG torch TTM15V, 4 m 6271432

© KEMPPI OY MINARC 120, 150 / 0546 – 9
6. TECHNICAL INFORMATION
The products meet conformity requirements for CE marking.
Minarc 120AU Minarc 150AU
Connection voltage
1 ~ phase 50/60Hz 240 V +10%...-20% 240 V +10%...-20%
Connection capacity 50% ED MMA 110 A/5,5 kVA 35 % ED MMA 140 A/7,5 kVA
50% ED TIG 120 A/3,5 kVA 35 % ED TIG 150 A/5,0 kVA
100 % ED MMA 80 A/3,9 kVA 100 % ED MMA 100 A/5,1 kVA
100 % ED TIG 80 A/2,2 kVA 100 % ED TIG 110 A/3,3 kVA
Mains cable/fuse,
delayed
1,5 mm² S - 3,3 m/10 A 2,5 mm² S - 3,3 m/15 A
Welding current
range
TIG 5 A/10 V...120 A/15 V TIG 5 A/10 V... 150 A/16 V
Metal arc
welding (MMA)
10 A/20,5 V...
110 A/24,4 V
Metal arc welding
(MMA)
10 A/20,5 V...
140 A/25,6 V
Electrodes, diameter Ø 1,5...2,5 mm Ø 1,5...3,25 mm
Welding current
control
stepless stepless
Open circuit voltage
(VRD)
30 V 30 V
Open circuit power <10 W <10 W
Efficiency 80% 80%
Power factor 0,6 (110 A/24,4 V) 0,60 (140A/25,5 V))
Degree of protection IP 23C IP 23C
Temperature class B (130°C)/H (180°C) B (130°C)/H (180°C)
Range of working
temperature
-20...+40°C -20...+40°C
Range of storage
temperature
-40...+60°C -40...+60°C
External
dimensions:
lengt 320 mm lengt 320 mm
width 123 mm width 123 mm
height 265 mm height 265 mm
Weight 4,0 kg without
connection cable
Weight 4,0 kg without
connection cable
4,6 kg with connection
cable
4,6 kg with connection
cable
Norms AS 1674.2 AS 1674.2
AS/NZS 3652 AS/NZS 3652
WTIA Tech note 22 WTIA Tech note 22
IEC 60974-1 IEC 60974-1
IEC 60974-10 IEC 60974-10
EN 50199 EN 50199

© KEMPPI OY10 – MINARC 120, 150 / 0546
7. DISPOSAL OF THE MACHINE
Do not dispose of electrical equipment together with normal waste!
In observance of European Directive 2002/96/EC on Waste Electrical and Electronic
Equipment and its implementation in accordance with national law, electrical equipment
that has reached the end of its life must be collected separately and returned to an
environmentally compatible recycling facility. As the owner of the equipment, you should
get information on approved collection systems from our local representative.
By applying this European Directive you will improve the environment and human
health!
8. TERMS OF GUARANTEE
Kemppi Oy provides a guarantee for products manufactured and sold by them if defects in
manufacture and materials occur. Guarantee repairs must be carried out only by an Authorised
Kemppi Service Agent. Packing, freight and insurance costs to be paid by orderer. The guarantee is
effected on the date of purchase. Verbal promises which do not comply with the terms of guarantee
are not binding on guarantor.
Limitations on guarantee
The following conditions are not covered under the terms of guarantee: defects due to natural wear
and tear, non-compliance with operating and maintenance instructions, connection to incorrect or
faulty supply voltage (including voltage surges outside equipment spec.), incorrect gas pressure,
overloading, transport or storage damage, fire of damage due to natural causes i.e. lightning or
flooding.
This guarantee does not cover direct or indirect travelling costs, daily allowances or accommodation.
Note: Under the terms of guarantee, welding torches and their consumables, feeder drive rolls and
feeder guide tubes are not covered. Direct or indirect damage due to a defective product is not
covered under the guarantee. The guarantee is void if changes are made to the product without
approval of the manufacturer, or if repairs are carried out using non-approved spare parts.
The guarantee is also void if repairs are carried out by non-authorised agents.
Undertaking guarantee repairs
Guarantee defects must be informed to Kemppi or authorised Kemppi Service Agents within the
guarantee period. Before any guarantee work is undertaken, the customer must provide proof of
guarantee or proof of purchase, and serial number of the equipment in order to validate the guarantee.
The parts replaced under the terns of guarantee remain the property of Kemppi.
Following the guarantee repair, the guarantee of the machine or equipment, repaired or replaced,
will be continued to the end of the original guarantee period.

KEMPPI OY
PL 13
FIN – 15801 LAHTI
FINLAND
Tel [phone]
Telefax [phone]
www.kemppi.com
KEMPPIKONEET OY
PL 13
FIN – 15801 LAHTI
FINLAND
Tel [phone]
Telefax [phone]
e-mail: myynti.fi@kemppi.com
KEMPPI SVERIGE AB
Box 717
S – 194 27 UPPLANDS VÄSBY
SVERIGE
Tel [phone]
Telefax [phone] 94
e-mail: [e-mail]
KEMPPI NORGE A/S
Postboks 2151, Postterminalen
N – 3103 TØNSBERG
NORGE
Tel [phone]
Telefax 33 34 60 10
e-mail: [e-mail]
KEMPPI DANMARK A/S
Literbuen 11
DK – 2740 SKOVLUNDE
DANMARK
Tel [phone]
Telefax 44 941 536
e-mail:[e-mail]
KEMPPI BENELUX B.V.
Postbus 5603
NL – 4801 EA BREDA
NEDERLAND
Tel [phone]
Telefax [phone]
e-mail: [e-mail]
KEMPPI (UK) Ltd
Martti Kemppi Building
Fraser Road
Priory Business Park
BEDFORD, MK443WH
ENGLAND
Tel [phone]
Fax [phone]
e-mail: [e-mail]
KEMPPI FRANCE S.A.
65 Avenue de la Couronne des Prés
78681 EPONE CEDEX
FRANCE
Tel [phone]
Telefax (01) 30 90 04 45
e-mail: [e-mail]
KEMPPI GmbH
Otto – Hahn – Straße 14
D – 35510 BUTZBACH
DEUTSCHLAND
Tel [phone]
Telefax (06033) 72 528
e-mail:[e-mail]
KEMPPI SP. z o.o.
Ul. Piłsudskiego 2
05-091 ZA¸BKI
Poland
Tel [phone]
Telefax [phone]
e-mail: info[email protected]
KEMPPI WELDING
MACHINES AUSTRALIA PTY LTD
P.O. Box 404 (2/58 Lancaster Street)
Ingleburn NSW 2565, Australia
Tel. [phone]
Telefax [phone]
e-mail: info[email protected]
www.kemppi.com
Ver. 9