Valid for serial no. 712−xxx−xxxx 501 GB 1006150449 015
ESAB AB, Welding Equipment, SE−695 81 Laxå, Sweden, declares under sole responsibility that
welding power source LAF 1250 from serial number 712 (2007 w.12) is designed and tested in con-
formity with standard EN 60974−1 and EN 60974−10 in accordance with the conditions in the directives (2006/95/EC) and (2004/108/EC).
Rights reserved to alter specifications without notice.
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1SAFETY
Users of ESAB welding equipment have the ultimate responsibility for ensuring that anyone who
works on or near the equipment observes all the relevant safety precautions. Safety precautions
must meet the requirements that apply to this type of welding equipment. The following recommendations should be observed in addition to the standard regulations that apply to the workplace.
All work must be carried out by trained personnel well−acquainted with the operation of the welding
equipment. Incorrect operation of the equipment may lead to hazardous situations which can result
in injury to the operator and damage to the equipment.
1.Anyone who uses the welding equipment must be familiar with:
S its operation
S location of emergency stops
S its function
S relevant safety precautions
S welding
2.The operator must ensure that:
S no unauthorised person is stationed within the working area of the equipment when it is
started up.
S no−one is unprotected when the arc is struck
3.The workplace must:
S be suitable for the purpose
S be free from draughts
4.Personal safety equipment
S Always wear recommended personal safety equipment, such as safety glasses, flame−proof
clothing, safety gloves.
S Do not wear loose−fitting items, such as scarves, bracelets, rings, etc., which could become
trapped or cause burns.
5.General precautions
S Make sure the return cable is connected securely.
S Work on high voltage equipment may only be carried out by a qualified electrician.
S Appropriate fire extinquishing equipment must be clearly marked and close at hand.
S Lubrication and maintenance must not be carried out on the equipment during operation.
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WARNING
ARC WELDING AND CUTTING CAN BE INJURIOUS TO YOURSELF AND OTHERS. TAKE PRECAUTIONS 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 take fumes and gases away 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.
NOISE − Excessive noise can damage hearing
SProtect your ears. Use earmuffs or other hearing protection.
SWarn bystanders of the risk.
MALFUNCTION − Call for expert assistance in the event of malfunction.
READ AND UNDERSTAND THE INSTRUCTION MANUAL BEFORE INSTALLING OR OPERATING.
PROTECT YOURSELF AND OTHERS!
WARNING
This product is intended for industrial use. In a domestic environment this
product may cause radio interference. It is the user’s responsibility to take
adequate precautions.
WARNING!
Read and understand the instruction manual
before installing or operating.
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!
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2INTRODUCTION
2.1General
LAF 1250 is a remote−controlled 3−phase welding power source designed for
high−efficiency mechanical gas metal arc welding (MIG/MAG) or sub arc welding
(SAW). It is always to be used in combination with ESAB‘s control box
A2−A6 Process Controller (PEH).
LAF is fan−cooled and monitored by a thermal overload protection.
When the protection enters into action a yellow indicating lamp on the front panel
goes on and is reset automatically as soon as the temperature has gone down to an
acceptable level.
The welding power source and the control unit are linked together over a 2−wire bus
enabling precision control of the welding process.
All welding parameter settings for the power source can be made by the operator on
the front panel of the control unit.
The operation of the power source is completely controlled and monitored by this
unit. Even the start and stop qualities can be set by way of the control unit. The
preset welding current parameters can also be monitored in the course of welding.
For more detailed information regarding the settings and the working mode of the
welding power source, please refer to the instruction manual for the
A2−A6 Process Controller.
2.2Technical data
LAF 1250
Voltage400/415/500 V, 350 Hz
400/440/550 V, 360 Hz
Permissible load at:
100 % duty cycle1250 A/ 44 V
Setting range
MIG/MAG60 A/ 17 V −1250 A/ 44 V
SAW40 A/ 22 V −1250 A / 44 V
No−load voltage51 V
No−load power220 W
Effiency0,87
Power factor0,92
Weight490 kg
Dimensions L x W x H774 x 598 x 1430
Class of enclosureIP 23
Class of application
Enclosure class
The IP code indicates the enclosure class, i. e. the degree of protection against penetration by solid
objects or water. Equipment marked IP 23 is designed for indoor and outdoor use.
Application class
The symbol indicates that the power source is designed for use in areas with increased
electrical hazard.
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3INSTALLATION
3.1General
The installation must be executed by a professional.
3.2Unpacking and erection
WARNING − TIPPING RISK!
Fasten the equipment − particularly if the ground is uneven or sloping.
SPlace the welding power source on a level foundation.
SMake sure there is nothing to prevent the cooling.
Lifting instructions
3.3Connections
SOn delivery the welding power source is
connected for 400 V. For other supply voltage,
switch over to the desired voltage on the main
transformer and the control transformer according
to the connection instructions on page 14.
SMake sure the mains cable has the right sectional
area and fuse it with an adequate fuse according to
applicable local directions (see table on page 8).
SConnect the earth cable to the screw marked .
STighten the cable support (1).
SConnect the mains cable to the main terminal
blocks L1, L2 and L3.
SConnect the control cable between the LAF
welding power source and the control unit to the
28−pole contact (2) inside the welding power source.
SConnect 1 pin socket measure cable (4).
SConnect a suitable welding and return cable to the contacts (3) marked + and−
on the front of the power source.
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Mains connection
LAF 125050 Hz60 Hz
Voltage400 V / 415 V500 V400 V / 440 V550 V
Current:
100%99 A80 A99 A80 A
Cable area3x35+ 25 mm
Fuse, slow100 A80 A100 A80 A
2
3x25+ 16 mm
2
3 x35+ 25 mm
2
3x25+ 16 mm
3.4PC board
DIP switches
The PC board (AP1) has two DIP switches (SW1 and SW2) which are preset on
delivery. The settings are not to be changed.
When spare parts are supplied the settings of the DIP switches must be checked
(and set, if necessary) before fitting the PC board into the welding power source.
SDIP switch SW1
To make the communication with the
A2−A6 Process Controller (PEH) work
DIP switch 1 (SW1) must be set.
SDIP switch SW2
DIP switch 2 (SW2) must be set in order to
inform the A2−A6 process controller (PEH)
about the rating of the power source that
is connected.
2
Setting of DIP switch SW1
SSet pole 6 to “OFF“ position and
all other poles to “ON“.
Setting of DIP switch SW2
SSet pole 2 to “OFF” position and all
other poles to “ON”.
Welding power source program
The welding power source program is
stored in the flash memory IC 6.
The capsule is fitted in a holder and is replaceable.
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4OPERATION
4.1General
General safety regulations for the handling of the equipment can be found on
page 4. Read through before you start using the equipment!
Note! Never use the welding power source without side plates.
4.2Controls
The front panel contains:
1.Main switch, breaking the incoming mains voltage for the welding power source.
2.Indicating lamp (white), showing that the main switch is activated.
3.Indicating lamp (yellow), showing that the thermal protection has entered into
action due to overheating in the transformer. The lamp is reset when the
temperature has gone down to an acceptable level.
4.Pushbutton, for the resetting of automatic fuse FU2 for 42 V supply voltage.
4.3Start−up
SConnect the return cable to the work piece.
SSet the main switch (1) to position “I“.
The white indicating lamp (2) goes on and the fan starts.
SSet the welding parameters and start welding by way of the control box
(see instruction manual 0443 745 xxx for A2−A6 Process Controller).
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5MAINTENANCE
5.1General
Note:
All warranty undertakings given by the supplier cease to apply if the customer
attempts to rectify any faults on the machine during the warranty period.
5.2Cleaning
SClean the welding power source as necessary.
Dry compressed air is recommended for the purpose.
WARNING!
Blocked air inlets or outlets will lead to overheating.
Note:
If the contactor has to be cleaned it must be taken apart, and all the pieces be
cleaned.
Alternatively, the contactor can be replaced.
WARNING!
Never use compressed air to clean the contactor without first taking it apart
completely.
6ORDERING OF SPARE PARTS
LAF 1250 DC is designed and tested in accordance with the international and European standards IEC/EN 60974−1 and IEC/EN 60974−10.
It is the obligation of the service unit which has carried out the service or repair work
to make sure that the product still conforms to the said standard.
Spare parts are ordered through your nearest ESAB representative, see back cover.
When ordering spare parts, please state machine type and number as well as designation and spare part number as shown in the spare parts list on page 15.
This will simplify dispatch and ensure you get the right part.
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Diagram
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List of components
C = Component designation in the circuit diagram
CDenominationRemarks
V2Silicon diode
C4Capacitor400 V
FU1Fuse16 A, 500 V
FU2Automatic fuse20 A
FU4Fuse1.25AT
FU5Fuse1.25AT
FU6Fuse3.15AT
KM1Contactor42 V, 50 Hz
AP1Circuit board
M1Fan
QFMain switch (black)
HL1Indicating lamp (white)
HL2Indicating lamp (yellow)
V1Thyristor1100 A/300 V
TC1Control transformer42 V, 900VA
AP2Circuit board, insulation
AP3Circuit board, EMC filter
TC2Transformer