ESAB TAF 1251 User manual

Instruction manual
0449 510 101 GB 20180123 Valid for: serial no. 126-xxx-xxxx
TAF 1251

TABLE OF CONTENTS
0449 510 101 © ESAB AB 2018
1SAFETY ....................................................................................................... 4
1.1 Meaning of symbols ............................................................................... 4
1.2 Safety precautions ................................................................................. 4
2INTRODUCTION.......................................................................................... 7
3TECHNICAL DATA ...................................................................................... 8
4INSTALLATION............................................................................................ 9
4.1 Location................................................................................................... 9
4.2 Connections............................................................................................ 10
5OPERATION ................................................................................................ 11
5.1 Controls................................................................................................... 11
6MAINTENANCE........................................................................................... 12
6.1 Cleaning .................................................................................................. 12
6.1.1 Welding power source.......................................................................... 12
6.1.2 Contactor.............................................................................................. 12
7ORDERING SPARE PARTS ........................................................................ 13
DIAGRAM ............................................................................................................ 14
CONNECTION INSTRUCTION............................................................................ 18
ORDERING NUMBERS....................................................................................... 19
Rights reserved to alter specifications without notice.

1 SAFETY
0449 510 101 -4- © ESAB AB 2018
1 SAFETY
1.1 Meaning of symbols
As used throughout this manual: Means Attention! Be Alert!
DANGER!
Means immediate hazards which, if not avoided, will result in immediate,
serious personal injury or loss of life.
WARNING!
Means potential hazards which could result in personal injury or loss of
life.
CAUTION!
Means hazards which could result in minor personal injury.
WARNING!
Before use, read and understand the instruction manual
and follow all labels, employer´s safety practices and Safety
Data Sheets (SDSs).
1.2 Safety precautions
Users of ESAB 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 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
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 equipment must be familiar with:
○ its operation
○ location of emergency stops
○ its function
○ relevant safety precautions
○ welding and cutting or other applicable operation of the equipment
2. The operator must ensure that:
○ no unauthorised person is stationed within the working area of the equipment
when it is started up
○ no-one is unprotected when the arc is struck or work is started with the
equipment
3. The workplace must:
○ be suitable for the purpose
○ be free from drafts

1 SAFETY
0449 510 101 -5- © ESAB AB 2018
4. Personal safety equipment:
○ Always wear recommended personal safety equipment, such as safety glasses,
flame-proof clothing, safety gloves
○ Do not wear loose-fitting items, such as scarves, bracelets, rings, etc., which
could become trapped or cause burns
5. General precautions:
○ Make sure the return cable is connected securely
○ Work on high voltage equipment may only be carried out by a qualified
electrician
○ Appropriate fire extinguishing equipment must be clearly marked and close at
hand
○ Lubrication and maintenance must not be carried out on the equipment during
operation
WARNING!
Arc welding and cutting can be injurious to yourself and others. Take precautions
when welding and cutting.
ELECTRIC SHOCK - Can kill
• Install and ground the unit in accordance with instruction manual.
• Do not touch live electrical parts or electrodes with bare skin, wet gloves or
wet clothing.
• Insulate yourself from work and ground.
• Ensure your working position is safe
ELECTRIC AND MAGNETIC FIELDS - Can be dangerous to health
• Welders having pacemakers should consult their physician before welding.
EMF may interfere with some pacemakers.
• Exposure to EMF may have other health effects which are unknown.
• Welders should use the following procedures to minimize exposure to
EMF:
○ Route the electrode and work cables together on the same side of
your body. Secure them with tape when possible. Do not place your
body between the torch and work cables. Never coil the torch or
work cable around your body. Keep welding power source and
cables as far away from your body as possible.
○ Connect the work cable to the workpiece as close as possible to the
area being welded.
FUMES AND GASES - Can be dangerous to health
• Keep your head out of the fumes.
• Use 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
• Protect your eyes and body. Use the correct welding screen and filter lens
and wear protective clothing.
• Protect bystanders with suitable screens or curtains.
NOISE - Excessive noise can damage hearing
Protect your ears. Use earmuffs or other hearing protection.

1 SAFETY
0449 510 101 -6- © ESAB AB 2018
MOVING PARTS - Can cause injuries
• Keep all doors, panels and covers closed and securely in place. Have only
qualified people remove covers for maintenance and troubleshooting as
necessary. Reinstall panels or covers and close doors when service is
finished and before starting engine.
• Stop engine before installing or connecting unit.
• Keep hands, hair, loose clothing and tools away from moving parts.
FIRE HAZARD
• Sparks (spatter) can cause fire. Make sure that there are no inflammable
materials nearby.
• Do not use on closed containers.
MALFUNCTION - Call for expert assistance in the event of malfunction.
PROTECT YOURSELF AND OTHERS!
CAUTION!
This product is solely intended for arc welding.
WARNING!
Do not use the power source for thawing frozen pipes.
CAUTION!
Class A equipment is not intended for use in residential
locations where the electrical power is provided by the
public low-voltage supply system. There may be potential
difficulties in ensuring electromagnetic compatibility of class
A equipment in those locations, due to conducted as well
as radiated disturbances.
NOTE!
Dispose of electronic equipment at the recycling
facility!
In observance of European Directive 2012/19/EC on Waste
Electrical and Electronic Equipment and its implementation
in accordance with national law, electrical and/or electronic
equipment that has reached the end of its life must be
disposed of at a recycling facility.
As the person responsible for the equipment, it is your
responsibility to obtain information on approved collection
stations.
For further information contact the nearest ESAB dealer.
ESAB has an assortment of welding accessories and personal protection equipment
for purchase. For ordering information contact your local ESAB dealer or visit us on
our website.

2 INTRODUCTION
0449 510 101 -7- © ESAB AB 2018
2 INTRODUCTION
TAF 1251 is a remote-controlled, two-phase AC welding power source designed for
high-throughput, mechanised submerged-arc welding (SAW).
The welding power source converts, via a thyristor bridge-rectifier, the secondary voltage's
sine wave to a square wave with excellent arc ignition and welding characteristics.
The welding power source is fan cooled and is overload protected by a thermal cut-out.
Re-setting takes place automatically as soon as the temperature has reduced to a permitted
level.

3 TECHNICAL DATA
0449 510 101 -8- © ESAB AB 2018
3 TECHNICAL DATA
TAF 1251
Voltage 346/400/415/500 V, 1  50 Hz
400/440/550 V, 1  60 Hz
Primary current Imax 249 A
Permissible load at:
100 % duty cycle

1250 A /44 V
Setting range 400A/28V–1250A/44V
No-load voltage 73 V
No-load power 240 W
Efficiency 87%
Power factor 0.77
Apparent power 86.2kVA
Active power 64.9kW
Weight 608 kg
Dimensions L × W × H 774 × 598 × 1228
Insulation class (transformer): F
Enclosure class IP 23
Enclosure class
The IP code indicates the enclosure class, i.e. the degree of protection against penetration
by solid objects or water.
Equipment marked IP23 is intended for indoor and outdoor use.

4 INSTALLATION
0449 510 101 -9- © ESAB AB 2018
4 INSTALLATION
The installation must be carried out by a professional.
NOTE!
Mains supply requirements
This equipment complies with IEC 61000-3-12 provided that the short-circuit
power is greater than or equal to Sscmin at the interface point between the user's
supply and the public system. It is the responsibility of the installer or user of the
equipment to ensure, by consultation with the distribution network operator if
necessary, that the equipment is connected only to a supply with a short-circuit
power greater than or equal to Sscmin. Refer to the technical data in the
TECHNICAL DATA chapter.
4.1 Location
WARNING!
Secure the equipment - particularly if
the ground is uneven or sloping.
• Place the welding power source on a level foundation.
• Make sure there is nothing to prevent the cooling.
Lifting instructions

4 INSTALLATION
0449 510 101 - 10 - © ESAB AB 2018
4.2 Connections
• On 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" chapter.
• Make sure the mains cable has the right sectional area
and fuse it with an adequate fuse according to applicable
local directions (see "Mains connection" table below in
this section).
•
Connect the earth cable to the screw marked .
• Connect the mains cable to the main terminal blocks L1
and L3.
• Tighten the cable support (1).
• Connect the control cable between the welding power
source and the control unit to the 28-pole contact (2)
inside the welding power source.
• Connect the 1-pin measuring cable (4) for measuring the
arc voltage to the return cable/welding head.
•
Connect a suitable welding and return cable to the contacts (3) marked on the
front of the power source.
Mains connection
TAF 1251 50 Hz 60 Hz
Voltage (V) 346 400 / 415 500 400 / 440 550
Phase current I1eff (A) 249 212 170 212 170
Cable area (mm2)2x(2x70+35) 2x(2x70+35) 2x95+50 2x(2x70+35) 2x95+50
Fuse, slow (A) 250 200 200 200 200
NOTE!
The mains cable areas and fuse sizes as shown above are in accordance with
Swedish regulations. For other regions, supply cables must be suitable for the
application and meet local and national regulations.