ESAB LKA 180 User manual

0349 300 002 Valid for serial no. 618−xxx−xxxx040928
LKA 180/240
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Service manual

INTRODUCTION 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RATING PLATE 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COMPONENT DESCRIPTION, LKA 180/240 4. . . . . . . . . . . . . .
CONNECTION DIAGRAM, LKA 180 Single−phase, 230 V 5.
CONNECTION DIAGRAM, LKA 180 3−phase, 400 V 6. . . . .
CONNECTION DIAGRAM, LKA 180 3−phase, 230/400 V 7.
CONNECTION DIAGRAM, LKA 240 3−phase, 400 V 8. . . . .
CONNECTION DIAGRAM, LKA 240 3−phase, 230/400 V 9.
CIRCUIT DIAGRAM, CIRCUIT BOARD AP1 10. . . . . . . . . . . . . .
COMPONENT POSITIONS, CIRCUIT BOARD AP1 12. . . . . . . .
DESCRIPTION OF OPERATION, CIRCUIT BOARD AP1 13. . .
LOAD CHARACTERISTICS 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TECHNICAL DATA 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WELDING DATA SELECTION 21. . . . . . . . . . . . . . . . . . . . . . . . . . .
SPARE PARTS LIST LKA 180/240 24. . . . . . . . . . . . . . . . . . . . . .

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INTRODUCTION
This service manual is intended for use by technicians with electrical training when carrying
out fault tracing and repair of the equipment.
At the end of the manual, there is a brief guide to using the machine in order to assist in
understanding the machine.
The manual contains all design modifications introduced up to and including September
2004.
Use the diagrams in the manual when tracing faults. The machine components are described
in alphabetical order on the pages foregoing the connection diagram.
The LKA 180 and 240 are designed and tested in accordance with international
standard EN 60974−1, EN 50199.
On completion of service or repair work, it is the responsibility of the person(s) etc.
performing the work to ensure that the product does not depart from the requirements
of the above standard.
WARNING
READ AND UNDERSTAND THE OPERATING MANUAL BEFORE INSTALLING OR OPERATING.
ARC WELDING AND CUTTING CAN BE INJURIOUS TO YOURSELF AND OTHERS. TAKE PRECAU-
TIONS WHEN WELDING. ASK FOR YOUR EMPLOYER’S SAFETY PRACTICES WHICH SHOULD BE
BASED ON MANUFACTURERS’ HAZARD DATA.
ELECTRIC SHOCK −Can kill
SInstall and earth the welding unit in accordance with applicable standards.
SDo not touch live electrical parts or electrodes with bare skin, wet gloves or wet clothing.
SInsulate yourself from earth and the workpiece.
SEnsure your working stance is safe.
FUMES AND GASES −Can be dangerous to health
SKeep your head out of the fumes.
SUse ventilation, extraction at the arc, or both, to keep fumes and gases from your breathing zone and
the general area.
ARC RAYS −Can injure eyes and burn skin.
SProtect your eyes and body. Use the correct welding screen and filter lens and wear protective
clothing.
SProtect bystanders with suitable screens or curtains.
FIRE HAZARD
SSparks (spatter) can cause fire. Make sure therefore that there are no inflammable materials nearby.
MALFUNCTION −Call for expert assistance in the event of malfunction.
PROTECT YOURSELF AND OTHERS!
Rights reserved to alter specifications without notice.

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RATING PLATE
The rating plate is secured to the back of the machine. The example shown below is the rating
plate for an LKA 240 with an explanation of how the plate should be read and interpreted.
1. LKA 240 is the type designation for this power source. The first letter, L, indicates that
the LKA 240 is a rectifier, while K indicates Compact (Kompakt in Swedish) and A indi-
cates the design generation.
The 240 indicates the maximum welding current.
2. These symbols indicate that the LKA 240 incorporates a transformer and rectifier.
3. This section indicates the voltage/current characteristic when welding and a current range
of 30 -- 200 A.
The voltage values of 15 and 24 V in the heading indicate that we comply with the in-
ternational arc characteristic as defined in IEC 974--1.
X =The duty cycle, indicating for how long a time welding can be carried out at the
specified welding data, expressed as a percentage of a ten--minute period.
I2=The current at the respective duty factors.
U2=The arc line characteristic voltage.
Uo=The open--circuit voltage.

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4. Indicates that the unit is intended for connection to a 400 V three−phase supply at 50 or
60 Hz.
I1= primary currents at the various load points.
5. IP21 indicates the enclosure class in respect of protection against penetrating objects and
water. Enclosure class IP21 indicates that the equipment is intended for indoor use,
while IP23 equipment is also suitable for outdoor use.
The symbol indicates that the rectifier is designed for use in areas of elevated electri-
cal risk.
6. The machine’s serial number, in the form of three groups of figures (xxx yyy zzz).
The first group (xxx) indicates the version. The figures represent the year and week of
approval of the version.
The second group (yyy) shows the year and week of final testing of the machine. For
example, 341 indicates Week 41, 1993.
The final group (zzz) consists of three or four figures, and is a serial number in the range
0001 to 9999.
7. Shows that ESAB complies with the international standard, IEC 974−1.

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COMPONENT DESCRIPTION, LKA 180/240
The following component description refers to the connection diagrams on the following
pages.
AP1 Circuit board with control electronics: see the diagram on page 10 and
description on page 13.
C1−C3 Capacitor PME 0.1µF, 400 VDC, transient and HF protection.
EV1 Fan, 24 VDC, fitted in the LKA 240 and the single−phase version of the
LKA 180.
HL1 Lamp, 28 V, white, lights when the main switch is On.
KM1 Contactor, 42 V operating voltage.
L1 Inductor.
M1 Wire feed unit motor.
QF1 Switch, 7−way in the LKA 180 and 10−way in the LKA 240.
R1 Resistor, 1 Ω, only fitted in the single−phase version of LKA 180.
R2 Resistor, 5.6 kΩ5 W, only fitted in the single−phase version of LKA 180.
SB1 Welding torch trigger switch
ST1 Thermal overload cutout, for protection against overload, fitted in the winding of
main transformer TM1. The switch operates (opens) at a temperature of 120 _C.
ST2 Thermal overload cutout, for protection against overload, fitted on the diode
bridge cooling fins (V1 −V6). It operates (breaks) at 110 _C in the single−phase
version of the LKA 180 and at 130 _C in other machines.
TC1 Control power supply transformer.
Supplied at 230 or 400 V and protected by a 1.6 A anti−surge fuse.
Secondary output voltages of 42, 27 and 20 V to circuit board AP1.
TM1 Main transformer.
V1−V6 Diode bridge, rectifier.
V7 LED, yellow. Lights if thermal overload cutouts ST1 or ST2 operate as a result of
high temperature.
XS1 9−pole connector.
XS2 5−pole connector.
XS3 7−pole connector.
XS4 2−pole connector.
XT1 Mains terminal block, 5−way.
XT2 Terminal block, positive and negative welding voltages.
XT3 6−pole terminal block for mains voltage selection.
Fitted only in the multi−voltage versions of the machine.
YV1 Solenoid valve

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CONNECTION DIAGRAM, LKA 180 Single−phase, 230 V
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The first 150 machines
were delivered with
switch 0408/8112.
The part No. in the
spare parts list is
referring to the other
switch, which has to be
used as spare part for
all machines.

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CONNECTION DIAGRAM, LKA 180 3−phase, 400 V
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When checking the no−load
voltages, load the machine with
a dummy load of 5.6 kΩ5 W,
connecting it between plus and
minus on the rectifier bridge.

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CONNECTION DIAGRAM, LKA 180 3−phase, 230/400 V
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When checking the no−load
voltages, load the machine with
a dummy load of 5.6 kΩ5 W,
connecting it between plus and
minus on the rectifier bridge.

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CONNECTION DIAGRAM, LKA 240 3−phase, 400 V
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When checking the no−load
voltages, load the machine
with a dummy load of 5.6 kΩ5
W, connecting it between plus
and minus on the rectifier
bridge.