TELWIN TIG 252 Professional Inverter Welder Instruction Manual

June 16, 2024
TELWIN

TELWIN TIG 252 Professional Inverter Welder

TELWIN-TIG-252-Professional-Inverter-Welder-product

Product Information

Specifications :

  • Model: Cod.955149
  • Power Source: (DC) (AC/DC)
  • Welding Types : TIG, HF/LIFT, MMA

Product Usage Instructions

Safety Precautions

DANGER OF FIRE

  •  Always be cautious of the risk of fire when using the product.

Take necessary precautions to prevent any fire accidents.

Protective Gear:

  • Always wear protective gloves to protect your hands from any potential hazards.
  • Ensure the use of protective goggles or safety glasses to protect your eyes from any potential risks.
  • It is mandatory to wear a protective mask to prevent inhalation of harmful fumes or dust.
  • For additional safety, it is recommended to wear protective earplugs or earmuffs to protect your ears from excessive noise.

Usage Restrictions:

  • People with metal prostheses are strictly prohibited from using the machine.
  • Users of vital electrical and electronic apparatus should never use the machine.
  • Entry into the working area is forbidden for unauthorized personnel.

Operating Instructions

  • Please read the instruction manual carefully before operating the product.
  • Ensure that the power source is compatible with the product’s requirements (DC or AC/DC).
  • Select the appropriate welding type based on your requirements

(TIG, HF/LIFT, MMA).

  • Connect the power source to the machine and ensure a secure connection.
  • Put on the necessary protective gear, including gloves, goggles/safety glasses, mask, and earplugs/earmuffs.

Follow the specific operating instructions for the chosen welding type.

  • Monitor the welding process closely and make any necessary adjustments.
  • After use, turn off the power source and disconnect it from the machine.

FAQ

Q: Can people with metal prostheses use the machine?

A : No, people with metal prostheses are not allowed to use the machine due to safety reasons.

Q: Are protective gloves and goggles necessary?

A : Yes, it is mandatory to wear protective gloves and goggles to ensure personal safety during operation.

Q: What welding types does the machine support?

A : The machine supports TIG, HF/LIFT, and MMA welding types.

INSTRUCTION MANUAL

Professional TIG (DC) (AC/DC) HF/LIFT, MMA welding machines with inverter.

TIG (DC) (AC/DC) HF/LIFT • MMA

DANGER: EXPLANATION OF DANGER, MANDATORY AND PROHIBITION SIGNS.

Symbols

  • DANGER OF ELECTRIC SHOCK
  • DANGER OF WELDING FUMES
  • DANGER OF EXPLOSION
  • WEARING PROTECTIVE CLOTHING IS COMPULSORY
  • WEARING PROTECTIVE GLOVES IS COMPULSORY
  • DANGER OF ULTRAVIOLET RADIATION FROM WELDING
  • DANGER OF FIRE
  • DANGER OF BURNS
  • DANGER OF NON-IONISING RADIATION
  • GENERAL HAZARD
  • DO NOT USE THE HANDLE TO HANG THE WELDING MACHINE.
  • EYE PROTECTION MUST BE WORN
  • NO ENTRY FOR UNAUTHORISED PERSONNEL
  • TELWIN-TIG-252-Professional-Inverter-Welder-fig15DO NOT USE POWER WASHERS TO CLEAN THE MACHINE
  • DO NOT USE WATER TO CLEAN THE MACHINE
  • DO NOT USE VEHICLES TO TOW THE MACHINE
  • WEARING A PROTECTIVE MASK IS COMPULSORY
  • WEARING EAR PROTECTORS IS COMPULSORY
  • USERS OF VITAL ELECTRICAL AND ELECTRONIC APPARATUS MUST NEVER USE THE MACHINE
  • PEOPLE WITH METAL PROSTHESES ARE NOT ALLOWED TO USE THE MACHINE
  • DO NOT WEAR OR CARRY METAL OBJECTS, WATCHES OR MAGNETISED CARDS
  • NOT TO BE USED BY UNAUTHORISED PERSONNEL
  • Symbol indicating separation of electrical and electronic appliances for refuse collection

INSTRUCTIONS FOR USE AND MAINTENANCE

WARNING! BEFORE USING THE WELDING MACHINE READ THE INSTRUCTION MANUAL CAREFULLY!

GUARANTEE AND CONFORMITY

INVERTER WELDING MACHINES FOR TIG AND MMA WELDING DESIGNED FOR

INDUSTRIAL AND PROFESSIONAL USE.

Note: In the following text the term “welding machine” will be used.

GENERAL SAFETY CONSIDERATIONS FOR ARC WELDING

The operator should be properly trained to use the welding machine safely and should be informed about the risks related to arc welding procedures, the associated protection measures and emergency procedures.

(Please refer to the applicable standard “EN 60974-9: Arc welding equipment. Part 9: Installation and Use).

Avoid direct contact with the welding circuit: the no-load voltage supplied by the welding machine can be dangerous under certain circumstances.

  1. When the welding cables are being connected or checks and repairs are carried out the welding machine should be switched off and disconnected from the power supply outlet.
  2. Switch off the welding machine and disconnect it from the power supply outlet  before replacing consumable torch parts.
  3. Make the electrical connections and installation according to the safety rules and legislation in force.
  4. The welding machine should be connected only and exclusively to a power source with the neutral lead connected to earth.
  5. Make sure that the power supply plug is correctly connected to the earth protection outlet.
  6. Do not use the welding machine in damp or wet places and do not weld in the rain.
  7. Do not use cables with worn insulation or loose connections.
  8. If a liquid cooling unit is present, filling operations must be carried out with the welding machine off and disconnected from the power supply.
  • Do not weld on containers or piping that contains or has contained flammable liquid or gaseous products.
  • Do not operate on materials cleaned with chlorinated solvents or near such substances.
  • Do not weld on containers under pressure.
  • Remove all flammable materials (e.g. wood, paper, rags etc.) from the working area.
  • Provide adequate ventilation or facilities for the removal of welding fumes near the arc; a systematic approach is needed in evaluating the exposure limits for the welding fumes, which will depend on their composition, concentration and the length of exposure itself.
  • Keep the gas bottle (if used) away from heat sources, including direct sunlight.

TELWIN-TIG-252-Professional-Inverter-Welder-fig27

  • Use electric insulation that is suitable for the torch, the workpiece and any metal parts that may be placed on the ground and nearby (accessible).
    This can normally be done by wearing gloves, footwear, head protection and clothing that are suitable for the purpose and by using insulating boards or mats.

  • Always protect your eyes with the relative filters, which must comply with UNI EN 169 or UNI EN 379, mounted on masks or use helmets that comply with UNI EN 175.

  • Use the relative fire-resistant clothing (compliant with UNI EN 11611) and welding gloves (compliant with UNI EN 12477) without exposing the skin to the ultraviolet and infrared rays produced by the arc; the protection must extend to other people who are near the arc by way of screens or non-reflective sheets.

  • Noise : If the daily personal noise exposure (LEPd) is equal to or higher than 85 dB(A) because of particularly intensive welding operations, suitable personal protective means must be used (Tab. 1).

TELWIN-TIG-252-Professional-Inverter-Welder-fig28

ELECTRIC AND MAGNETIC FIELDS MAY BE DANGEROUS

Electric current flowing through any conductor causes localized electric and magnetic fields (EMF). Welding current creates an EMF field around welding and welding equipment. EMF fields may interfere with some medical implants (e.g. pacemakers, respiratory equipment, metallic prostheses etc.).Protective measures for persons wearing medical implants have to be taken.
For example, access restrictions for passers-by or individual risk assessment for welders.

This welding machine complies with technical product standards for exclusive use in an industrial environment for occupational use. It does not assure compliance with the restrictions for use by layman. All operators should follow the rules listed herebelow, in order to minimize exposure to EMF fields from the welding circuit:

  • route the welding cables together. Secure them with tape when possible;

  • place your trunk and head as far away as possible from the welding circuit;

  • never coil welding cables around metal objects or your body;

  • do not place your body between welding cables;

  • keep welding cables on the same side of your body;

  • connect the work clamp to the work piece as close as possible to the area being welded;

  • do not work next to welding power sources;

  • all operators should keep the required minimum distances as given in the EMF data sheet;

  • distance from the EMF source to a point beyond which the exposure is less than 20% of the lowest permissible value: d = 35 cm (1/N/PE 230V), 65 cm (3P + T 400V).

  • Class A equipment:

This welding machine conforms to technical product standards for exclusive use in an industrial environment and for professional purposes. It does not assure compliance with electromagnetic compatibility in domestic dwellings and in premises directly connected to a low-voltage power supply system feeding buildings for domestic use.

EXTRA PRECAUTIONS

WELDING OPERATIONS:

  • In environments with increased riskof electric shock;
  • In confined spaces;
  • In the presence of flammable or explosive materials;

MUST BE evaluated in advance by an “Expert supervisor” and must always be carried out in the presence of other people trained to intervene in emergencies. All protective technical measures MUST be taken as provided in 7.10; A.8; A.10 of the applicable standard EN 60974-9: Arc welding equipment. Part 9: Installation and Use”.

  • Welding MUST NOT be allowed if the welding machine or wire feeder is supported by the operator (e.g. using belts).
  • The operator MUST NOT BE ALLOWED to weld in raised positions unless safety platforms are used.
  • VOLTAGE BETWEEN ELECTRODE HOLDERS OR TORCHES: working with more than one welding machine on a single piece or on pieces that are connected electrically may generate a dangerous accumulation of no-load voltage between two different electrode holders or torches, the value of which may reach double the allowed limit. An expert coordinator must be designated to measuring the apparatus to determine if any risks subsist and suitable protection measures can be adopted, as foreseen by section 7.9 of the applicable standard ”EN 60974-9: Arc welding equipment. Part 9: Installation and Use”.
  • The use of the machine must be limited to the operator only.
  • The operator must disconnect the cable and the electrode holder from the machine once the MMA welding is over.
  • The area around the welding machine must be forbidden to third parties. It also should not be left unattended.
  • The torches not in use should be stored in their housing.

RESIDUAL RISKS

  • OVERTURNING : position the welding machine on a horizontal surface of adequate capacity for the weight; otherwise (e.g. tilted, disconnected flooring, etc.) there is an overturning hazard.
    It is forbidden to lift the trolley together with the welding machine and the cooling unit (when present).
    MISUSE: it is dangerous to use the welding machine for any work other than intended use (e.g. defrosting water mains piping).

  • RISK OF BURNS Some parts of the welding machine (torch, electrode-holder clamp) and the adjacent areas can reach temperatures over 65°C: adequate protective clothing must be worn. Let the just welded workpiece cool before touching it!

  • MISUSE: it is dangerous for more than one operator to simultaneously use the welding machine.

  • WELDING MACHINE MOVEMENT : always secure the cylinder using suitable devices to prevent its accidental fall (if used).

  • Do not use the handle to hang the welding machine.

ENVIRONMENTAL CONDITIONS (EN 60974-1)

  • Use the welding machine with the following environmental conditions only:
  • ambient temperature between -10°C and 40°C;
  • relative humidity of the air not exceeding 50% at 40°C;
  • relative humidity of the air not exceeding 90% at 20°C;
  • The surrounding air must be free of dust, acid, gas or corrosive substances, etc.

STORAGE

  • Position the machine and its accessories (with or without packaging) in closed premises.
  • The ambient temperature must be between -20°C and 55°C. If the machine is planned with liquid cooling and an ambient temperature under 0°C: use the anti-freeze liquid suggested by the manufacturer or completely empty the hydraulic circuit and the tank of liquid. Always use adequate measures to protect the machine from humidity, dirt and corrosion.

DISPOSAL

  • Do not dispose of this welding machine as normal household waste at the end of its life cycle.
  • The user is responsible for disposing of this electrical equipment in collection points designated for disposal and recycling of electrical equipment or contact the shop where you purchased the product. This provision only refers to disposal of the equipment within the European Union (WEEE).

INTRODUCTION AND GENERAL DESCRIPTION

INTRODUCTION

This welding machine is a source of current for arc welding, manufactured specifically for  TIG (AC / DC) welding with HF or LIFT strike and MMA welding of coated electrodes (rutile,acid, basic).

In alternating current, TIG AC allows you to weld aluminium and its alloys (AlSi, AlMg), while in direct current, TIG DC allows you to weld steel (carbon, stainless, low alloy and high alloy) and heavy metals (copper, nickel, titanium and their alloys). The specific characteristics of this welding machine (INVERTER), such as the high speed and adjustment precision give excellent welding quality. Adjustment with the “inverter” system on the power line input also determines a drastic reduction in volume both of the transformer and the levelling reactance, allowing manufacture of a welding machine with extremely contained volume and weight, enhancing its manageability and movement.

MAIN CHARACTERISTICS TIG

  • AC/DC current adjustment and character parameters.
  • HF/LIFT strike.
  • Continuous/pulse operation.
  • Selection modes 2T, 4T, 4T Bi-level, 2T Spot, 4T Spot, Thin Spot.
  • Connection and setting of the water cooling unit (G.R.A.) (R.A. versions only).

MMA

  • Current, Arc force and Hot Start settings.
  • Anti-stick protection.
  • Average value continuous/pulse operation (if planned).
  • VRD device.

OTHER

  • Display of parameters and selected modes.
  • Saving and referencing possible of customised programs (JOB).
  • Facilitated referencing of default parameters (DEFAULT) and simplified default mode

PROTECTION

  • Thermostatic protection
  • Protection against irregular voltage (power supply voltage too high or too low).
  • Protection against accidental short-circuits caused by contact between torch and earth.
  • Anti-stick (MMA).
  • Protection against overheating and insufficient pressure on the water cooling circuit of the torch (R.A. versions only).

OPTIONAL ACCESSORIES

  • Various models of TIG torches.
  • MMA welding kit.
  • Various consumables kit.
  • Auto-darkening mask: with fixed or adjustable filter.
  • Manual and pedal remote commands.
  • Argon cylinder adapter.
  • Gas fitting and gas tube for cylinder connection.
  • Pressure reducer with gauge.
  • Water cooling unit.
  • Coolant liquid.
  • Trolleys in various solutions.

TECHNICAL SPECIFICATIONS

DATA PLATE

The main data on use and performance of the welding machine are summarised on the rating plate with the following meaning:

Fig. A

TELWIN-TIG-252-Professional-Inverter-Welder-fig89

  1. EUROPEAN reference standard for safety and construction of arc welding machines.

  2.  Manufacturer’s name and address.

  3.  Name of model.

  4. Symbol of welding machine internal structure.

  5. Symbol of planned welding procedure.

  6. Symbol S : indicates cleaning operations can be carried out in an environment with increased risk of electric shock (e.g. in close proximity of large metal masses).

  7. Symbol of the power supply:

    • 1~: single-phase alternating voltage;
    • 3~: three-phase alternating voltage.
  8.  Protection rating of the casing.

  9. Characteristic data of the power supply:

    • U1 : Alternating voltage and power supply frequency to the welding machine (allowed limits ±10%).
    • I1 max : Absorbed maximum current from line.
    • I1 eff : Effective power supply current.
  10. Welding circuit performance:

    •   U0 : maximum no load voltage (welding circuit open).

    • I2/U2 : Normalized corresponding current and voltage which can occur supplied by
      the welding machine during welding.

    • X : Duty cycle ratio: indicates the time during which the welding machine can supply the corresponding current (same column). It is expressed as a %, based on a 10min cycle (e.g. 60% = 6 working minutes, 4 rest minutes; and so on). If the use factors (of plate, referring to 40°C ambient temperature) are surpassed, the thermal switch activates (the welding machine stays in stand-by until its temperature goes back within the permitted limits).

    • A/V-A/V : It indicates the settings range of the welding current (minimum- maximum) at the corresponding arc voltage.

  11. Serial number to identify the welding machine (essential for technical assistance, spare part requests, tracing of product origin).

  12. Value of delayed activation fuses to implement for line protection.

  13. Symbols referring to safety standards whose meaning is outlined in chapter 1 “General safety for arc welding”.

Note : The data plate shown above is an example to give the meaning of the symbols and numbers; the exact values of technical data for the welding machine in your possession must be checked directly on the data plate of the welding machine itself.

OTHER TECHNICAL DATA

  • WELDING MACHINE : see table (TAB. 1).TELWIN-TIG-252-Professional-Inverter-Welder-fig102
  • AVERAGE CONSUMPTION OF WELDING GAS : see table (TAB. 2).TELWIN-TIG-252-Professional-Inverter-Welder-fig103
  • TORCH : see table (TAB. 3).TELWIN-TIG-252-Professional-Inverter-Welder-fig104
  • ELECTRODE-HOLDER CLAMP : see table (TAB. 4).TELWIN-TIG-252-Professional-Inverter-Welder-fig105

The weight of the welding machine is outlined in table 1 (TAB. 1).

DESCRIPTION OF THE WELDING MACHINES

BLOCK DIAGRAM

The welding machine is essentially composed of power and control modules created on printed circuits optimised to obtain maximum reliability and less maintenance. This welding machine is controlled by a microprocessor that allows setting a high number of parameters to enable optimal welding in every condition and on all material. It is however necessary, for its complete use, to know the operating potential.

Description (FIG. B)

TELWIN-TIG-252-Professional-Inverter-Welder-fig90

  1. Power line input, rectifier unit and levelling capacitors.
  2. Switching bridge (IGBT) with transistors and drivers: it switches the voltage of the rectified line to alternating, high frequency voltage and adjusts power based on the required welding current/voltage.
  3. High frequency transformer: primary winding is powered with the voltage converted by block 2; it has the function of adapting voltage and current to the values necessary forthe arc welding procedure and, at the same time, galvanically isolate the welding circuit from the power line.
  4. Secondary rectifier bridge with levelling inductance: it switches the alternating voltage / current provided by secondary winding to direct current / voltage with very low ripple.
  5.  Switching bridge to transistors (IGBT) and drivers; transforms output current to secondary from DC to AC for TIG AC welding (if planned).
  6. Control and adjustment electronics; instantly controls the welding current value and compares it to the value set by the operator; it modulates control impulses of the drivers of the IGBT executing adjustment.
  7. Welding machine operating control logic: sets the welding cycles, controls the actuators, supervises the safety systems.
  8. Setting and display panel of the parameters and the operating modes.
  9. HF strike generator.
  10. EV gas protection solenoid valve.
  11. Welding machine cooling fan.
  12. Remote adjustment.

CONTROL, ADJUSTMENT AND CONNECTION DEVICES

Rear panel (Fig. C)

TELWIN-TIG-252-Professional-Inverter-Welder-fig91

  1. Main switch O/OFF – I/ON.
  2. Supply cable (2P + E (Single-phase)), (3P + E (Three-phase)).
  3. Fitting for gas tube connection (cylinder pressure reducer).
  4. Auxiliary fuse of water cooling unit (G.R.A.) with reference to the wiring diagram (if planned).
  5. Connector for water cooling unit (if planned).
  6. Connector for remote controls:

2 different types of remote control can be applied to the welding machine, using the specific 14-pole connector on the rear. Each device is automatically recognised and allows adjustment of the following parameters:

Pedal remote command :

the value of the current is determined by the position of the pedal. Furthermore, in TIG 2T mode, pressing the pedal acts as a start command for the machine placed on the torch button (if installed).

Remote command with two potentiometers:

the first potentiometer adjusts the main current. The second potentiometer adjusts another parameter that depends on the active welding mode. Turning this potentiometer, the parameter is displayed you are editing (which is no longer controllable with the panel knob). The meaning of the second potentiometer is: ARC FORCE if in MMA mode and END RAMP if in TIG mode.

Front panel (Fig. D, E)

TELWIN-TIG-252-Professional-Inverter-Welder-fig92 TELWIN-TIG-252-Professional-Inverter-Welder-fig108

  1. Positive (+) fast coupling for connecting the welding cable.
  2. Negative (-) fast coupling for connecting the welding cable.
  3. Connector for connecting the torch control cable.
  4. Fitting for connecting the gas tube of the TIG torch.
  5. Control panel:

Main setting button of welding process.

Short press (PROCESS):

  • welding with coated electrode (MMA).
  • TIG welding with high frequency ark strike (TIG HF).
  • TIG welding with arc strike starting with contact (TIG HF).
  • in TIG mode, it indicates direct current welding (DC).
  •  in TIG mode, it indicates alternating current welding (AC), if installed.

Prolonged press (JOB):

  • Where planned (Fig. D), it allows management of the default or saved welding programs: reference and saving menu. Selection using multifunctional knob 5c. Exit without saving with short press.

Selection button of operating mode.

Short press (MODE):

  • welding begins when the torch button is pressed and ends when the torch button is released.
  • welding begins when the torch button is pressed and released, and ends only when the torch button is pressed and released a second time.
  • welding begins when the torch button is pressed and released. On each short press/release the current passes from the value set to the value and vice versa. Welding ends when the button is pressed for a set long time.
  • enables spot welding (0.1-10s) with duration time control of the welding on a display (flashing icon).
  • enables short spot welding (0.01-0.09s) with duration time control of the welding on a display (flashing icon).

Prolonged press (PULSE):

  • in TIG, it enables pulsation of the current on 2 levels for reduced thermal contribution welding on thin materials with characteristic parameters setting TELWIN-TIG-252-Professional-Inverter-Welder-fig61 and .
  • in MMA it allows pulsation of the current at average value to facilitate vertical welding with setting of the characteristic parameters and .
  • in TIG, it allows pulsation of the current for welding thin materials with an automatic setting at default values of the characteristics parameters  and based on the current set.

Multifunction knob with button and rotation.

Based on the settings and the modes prepared, it enables selection and adjustment of the relevant parameters by displaying the value set on the display.

In particular, for the MMA process, the parameters editable and shown on the display (Fig. D-5d, E-5d) are:

enabling/disabling the “Voltage Reduction Device” for a safe start at low voltage.

initial overcurrent to optimise welding arc strike (0-100% adjustment).

TELWIN-TIG-252-Professional-Inverter-Welder-fig61dynamic overcurrent to optimise fluidity of the welding and avoid sticking of the electrode (0-100% adjustment).
main welding current in simple mode or in pulse mode, it is the average current value you want to maintain (output current in Amperes).

Note: the minimum value of the pulse is not set but calculated, in relation to the time function parameters, so that the average current is equal to that set.

represents the number of pulsations per second (value in Hertz with 0.2- 99Hz adjustment).

represents the ratio between the duration of the pulse compared to the total duration of the cycle (percentage value with 10-99% adjustment).

In particular, for the TIG process, the parameters editable and shown on the display (Fig. D-5d, E-5d) are:

pre-gas time of safety gas flow before starting welding (0-10 seconds adjustment).

initial current maintained for a set time in 2T and for the time the button is pressed in 4T (adjustment in Amperes).

N.B. : the parameters Is and Ts can also be edited with the pedal remote command. Adjustment, however, must be made before activating the command itself.

TELWIN-TIG-252-Professional-Inverter-Welder-fig61main welding current (output current in Amperes).

– in PULSE and Bi-Level mode, it represents the ratio between the maximum value of the pulse current and the main current (percentage value with adjustment 1-200%).

pulsation frequency, i.e. the parameter that adjusts the total time in which the current pulses on the two levels set and also, for AC/DC models in TIG AC, represents the repetition frequency of the entire current wave (positive and negative, adjustment in Hertz).

balance percentage, in PULSE (AC/DC) mode is the ratio between the time in which the current is at the highest level and the total pulsation period and also for AC/DC models in TIG AC it represents the ratio between the time with positive current and the time with negative current.

final ramp time of the current from value I2 to Iend , in OFF ramp not present (0.1-10 seconds adjustment).
final current, in 2T it is the current value of the arc after the final ramp if the ramp time is over zero, in 4T it is the current maintained after the final ramp for the entire time in which the torch button remains pressed (adjustment in Amperes).

post-gas time of safety gas flow starting from welding stoppage (0-10 seconds adjustment).

Preheating energy, if installed, only for AC/DC models in TIG AC adjusts preheating of the electrode to facilitate start-up. In OFF pre-heating not present (mm setting in relation to the diameter of the electrode used).

Other explanatory icons on the display:

warning/alarm, in general, combined with the code indicated on the display, drawing attention to possible anomalies/automatic protection activated on the welding machine.

thermal protection, combined with and the code on the display, warning the condition of internal heating limits has been reached.

active output, indicates voltage is present in the output sockets of the welding machine.
 remote command, indicates connection and control is active on the external commands or on the torch.

position pointer, in 4T with under a preset value, it indicates setting of a minimum initial current that makes the welding arc visible with button pressed. This allows precise selection of the starting point of the welding (if the initial current is set beyond a

certain limit the function automatically disables).

where planned, combined with the display indication of the active JOB number, it indicates the selected program whose parameters can be displayed, edited and saved.

when active, it indicates saving in progress of the welding program as set.

where planned, it indicates management of the cooling unit (G.R.A.) for compatible torches. Setting occurs by switching on the welding machine with the buttons 5a and 5c pressed simultaneously and selecting by rotating the knob 5c “ON” (G.R.A. enabled) or OFF (G.R.A. disabled). Save the selection by further pressing button 5c.

factory parameters, indicates setting of all the parameters at a preset value useful for wide-ranging operativity. The user can set the main current as wished to alter the other automatic settings.

DEFAULT reset PROCEDURE

It is possible to re-activate this condition at any time by switching off and back on the welding machine with the button on the multi-function knob (Fig. D and E-5c) pressed.

LOAD button

where planned (Fig. E), it allows passage to the management menu of the default or saved welding programs (JOB). Selection using multifunctional knob 5c.

SAVE or GAS TEST button

where planned, in general with a short press, it executes the GAS TEST by releasing gas from the circuit for approx. 10 seconds (pipe bleeds, flow rate adjustment). Instead, the JOB menu allows you to exit without saving (short press) or alternatively saving the active settings (prolonged press ).

Explanatory service messages on the alphanumerical display (Fig. D-5d, E-5d):

  • AL.1 : the primary circuit protection thermal switch has been triggered (if installed).
  • AL.2 : the secondary circuit protection thermal switch has been triggered.
  • AL.3 : power line overvoltage protection has been triggered.
  • AL.4 : power line undervoltage protection has been triggered.
  • AL.8 : auxiliary voltage out of range.
  • AL.9 : malfunctioning of the cooling unit (if planned).
  • AL.13 : offline internal communication (if planned).
  • AL.20 : temperature monitoring sensor has been triggered (if planned).
  • AL.28 : duty cycle ratio monitoring has been triggered.
  • AL.30 : overcurrent protection has been triggered.

Resetting is automatic when the reason for alarm activation stops.
On switch-off, it is normal for the voltage protection to appear for a few seconds.

INSTALLATION

WARNING! CARRY OUT ALL INSTALLATION OPERATIONS AND ELECTRICAL CONNECTIONS WITH THE WELDING MACHINE COMPLETELY SWITCHED OFF AND DISCONNECTED FROM THE POWER SUPPLY OUTLET. THE ELECTRICAL CONNECTIONS MUST BE MADE ONLY AND EXCLUSIVELY BY AUTHORISED OR QUALIFIED PERSONNEL.

SET-UP (Fig. Q)

TELWIN-TIG-252-Professional-Inverter-Welder-fig101

Unpack the welding machine, assemble the detached parts, contained in the packaging (if planned).

Assembling the clamp-return cable (Fig. F)

TELWIN-TIG-252-Professional-Inverter-Welder-fig109

Assembling the welding cable electrode-holder clamp (Fig. G)

TELWIN-TIG-252-Professional-Inverter-Welder-fig110

POSITION OF THE WELDING MACHINE

Choose the place to install the welding machine so that the cooling air inlets and outlets are not obstructed (forced circulation by fan, if present); at the same time make sure that conductive dusts, corrosive vapours, humidity etc. will not be sucked into the machine. Leave at least 250mm free space around the welding machine.

WARNING! Position the welding machine on a flat surface with sufficient carrying capacity for its weight, to prevent it from tipping or moving hazardously.

CONNECTION TO THE MAIN POWER SUPPLY

  • Before making any electrical connection, make sure the rating data of the welding machine correspond to the mains voltage and frequency available at the place of installation.
  • The welding machine should only be connected to a power supply system with the neutral conductor connected to earth.
  • To ensure protection against indirect contact use residual current devices of the following types:
  • Type A ( ) for single phase machines;
  • Type B ( ) for 3-phase machines.
  • In order to satisfy the requirements of the EN 61000-3-11 (Flicker) standard we recommend connecting the welding machine to the interface points of the main power supply that have an impedance of less than: Zmax = 0.230 Ohm (1/N/PE 230V) Zmax = 0.280 Ohm (3P+T 400V)
  • The IEC/EN 61000-3-12 Standard does not apply to the welding machine. If the welding machine is connected to an electrical grid, the installer or user must make sure that the machine can indeed be connected (if necessary, consult the company that manages the electrical grid).

Plug and outlet

Connect a normalised plug (2P + P.E) (1~); (3P + P.E) (3~) – having sufficient capacity- to the power cable and prepare a mains outlet fitted with fuses or an automatic circuit-breaker; the special earth terminal should be connected to the earth conductor (yellow-green) of the power supply line. Table (TAB.1) shows the recommended delayed fuse sizes in amps, chosen according to the max. nominal current supplied by the welding machine, and the nominal voltage of the main power supply. voltage of the main power supply.

WARNING! Failure to observe the above rules will make the (Class 1) safety system installed by the manufacturer ineffective with consequent serious risks to persons (e.g. electric shock) and objects (e.g. fire).

CONNECTION OF THE WELDING CABLES

WARNING! BEFORE MAKING THE FOLLOWING CONNECTIONS MAKE SURE

THE WELDING MACHINE IS SWITCHED OFF AND DISCONNECTED FROM THE POWER SUPPLY OUTLET.

Table (TAB. 1) gives the recommended values for the welding cables (in mm2) depending on the maximum current supplied by the welding machine.

TIG welding

Connecting the torch

  • Insert the current cable in the specific fast clamp (-). Connect the five-pole connector (torch button) to the specific socket. Connect the gas tube of the torch to the specific connection.

Connecting the welding current return cable

  • Connect the cable to the piece to be welded or the metal bench on which the workpiece is placed, as close as possible to the joint being worked. Connect this cable to the clamp with the symbol (+).

Gas cylinder connection

  • Screw the pressure reducer to the gas cylinder by imposing the specific reduction supplied as an accessory (when Argon gas is used).
  • Connect the input hose of the gas reducer and tighten with the supplied strip.
  • Loosen the setting ring nut of the pressure reducer before opening the cylinder valve.
  • Open the cylinder and adjust the quantity of gas (l/min) according to the illustrative use data, see table (TAB. 2); any adjustments in gas flow can be carried out during welding always using the pressure reducer ring nut. Check the tubing and fittings.

ATTENTION! Always close the gas cylinder valve at the end of work.

MMA WELDING

Almost all coated electrodes are connected to the positive pole (+) of the power source; as an exception to the negative pole (-) for acid coated electrodes. Connecting the electrode-holder clamp welding cable On the end take a special terminal that is used to close the uncovered part of the electrode. This cable is connected to the terminal with the symbol (+) Connecting the welding current return cable This is connected to the piece being welded or to the metal bench supporting it, as close as possible to the join being made.

This cable is connected to the terminal with the symbol (-)

Warnings:

  • Turn the welding cable connectors right down into the quick connections (if present), to ensure a perfect electrical contact; otherwise the connectors themselves will overheat, resulting in their rapid deterioration and loss of efficiency.
  • The welding cables should be as short as possible.
  • Do not use metal structures that are not part of the workpiece to substitute the return cable of the welding current: this could jeopardize safety and result in poor welding.

WELDING PROCESS DESCRIPTION

TIG WELDING

TELWIN-TIG-252-Professional-Inverter-Welder-fig94

TIG welding is a welding procedure that takes advantage of the heat produced by the electric arc which is struck, and maintained, between an infusible electrode (Tungsten) and the piece to weld. The Tungsten electrode is supported by a torch suitable for transmission of the welding current and protecting the electrode itself and the welding bath from atmospheric oxidation through an inert gas flow (normally Argon: Ar 99.5%) which exits the ceramic nozzle (Fig. H).

TELWIN-TIG-252-Professional-Inverter-Welder-fig106

For the welding to be good, the correct diameter of the electrode must be used with the recommended current, see table (TAB. 5). The electrode normally projects from the ceramic nozzle by 2-3 mm, but can reach 8 mm for welding edges.

TELWIN-TIG-252-Professional-Inverter-Welder-fig95

TELWIN-TIG-252-Professional-Inverter-Welder-fig96

The weld is created by the edges that melt. Filler metal is not needed when welding suitably prepared thin material (up to about 1 mm) (Fig. I). A greater thickness requires rods made from the same material as the basic material and with a suitable diameter, with edges that have been suitably prepared (Fig. L). For welding to be successful, the pieces must be carefully cleaned and free from oxide, grease, oil, solvent, etc.

HF and LIFT strike

HF strike:

The electric arc is struck without contact between the tungsten electrode and the piece  being welded, by means of a spark generated by a high frequency device. This strike mode does not entail either tungsten inclusions in the weld pool or electrode wear and gives an easy start in all welding positions.

Procedure:

Press the torch button, bringing the tip of the electrode close to the piece (2 -3mm), wait for the arc strike transferred by the HF pulses and, when the arch has struck, form the weld pool on the piece and proceed along the joint. If there are difficulties in striking the arc even though the presence of gas is confirmed and the HF discharges are visible, do not insist for long in subjecting the electrode to HF action, but check the integrity of the surface and the shape of the tip, dressing it on the grinding wheel if necessary. At the end of the cycle the current will fall at the slope down setting.

LIFT strike:

The electric arc is struck by moving the tungsten electrode away from the piece to be welded. This strike mode causes less electrical radiation disturbance and reduces tungsten inclusions and electrode wear to a minimum. Procedure:

Place the tip of the electrode on the piece, using gentle pressure. Press the torch button right down and lift the electrode 2-3mm with a few moments’ delay, thus striking the arc. Initially the welding machine supplies a current ILIFT , after a few moments the welding current setting will be supplied. At the end of the cycle the current will fall to zero at the slope down setting.

TIG DC welding

TELWIN-TIG-252-Professional-Inverter-Welder-fig97.

TIG DC welding is suitable for all low- and high-carbon steels and the heavy metals, copper, nickel, titanium and their alloys. For TIG DC welding with the electrode to the (-) terminal the electrode with 2% thorium (red band) is usually used or else the electrode with 2% cerium (grey band). It is necessary to sharpen the tungsten electrode axially on the grinding wheel, as shown in FIG. M, making sure that the tip is perfectly concentric to prevent arc deviation. It is important to carry out the grinding along the length of the electrode. This operation should be repeated periodically, depending on the amount of use and wear of the electrode, or when the electrode has been accidentally contaminated, oxidised or used incorrectly.

TIG AC welding (if installed)

This type of process allows welding of metals such as aluminium and magnesium that form a protective and insulating oxide on their surface. By inverting the welding current polarity, you can “break” the surface layer of oxide via a mechanism called “ionic sandblasting”. The current is alternating positive (I+) and negative (I-) on the workpiece to weld.  During the time (I-) the oxide is removed from the surface (“cleaning” or “pickling”) allowing bath formation. During the time (I+) the maximum thermal contribution takes place on the workpiece allowing welding. The possibility of changing the balance in AC parameter allows you to work on the duration times of each pole.

TELWIN-TIG-252-Professional-Inverter-Welder-fig98

Higher positive balance values allow faster welding, higher penetration, more concentrated arc, a narrower welding bath and limited heating of the electrode. Lower negative values allow better cleaning of the workpiece. Using too low a balance value would widen the arc and the deoxidised part, heating of the electrode resulting in ball formation on the tip and more difficult striking and direction of the arc. Using a too high balance value would cause a “dirty” welding bath with dark inclusions. The figure (Fig. N) summarises the effects of changing the AC welding parameters.

Procedure

  • Use the knob to adjust the welding current to the required rate; adjust this value during welding to adapt to the actual heat transfer required.
  • Press the torch button, checking correct flow of gas from the torch; if necessary, calibrate the pre-gas and post-gas time; these times should be adjusted based on the working conditions, in particular the post-gas delay must be such to allow cooling of the electrode and the bath when welding is complete without coming in contact with the atmosphere (oxidation and contamination).

TIG mode with 2T sequence :

  • Fully press the torch button (T.B.) to strike the arc with current Is. Then, the current increases according the START RAMP up to the welding current value.
  • – To interrupt welding, release the torch button which would cause gradual current elimination (if END RAMP function inserted) or on immediate extinguishing of the arc with immediate post-gas.

TIG mode with 4T sequence (Fig. O):

TELWIN-TIG-252-Professional-Inverter-Welder-fig99

  • The first press of the button strikes the arc with current IS. On releasing the button, the current varies according to the START RAMP function up to the welding current value; this value is maintained also with the button released. When the button is pressed again, the current decreases according to the END RAMP function up to Bend. The latter is maintained up to release of the button which terminates the welding cycle starting with the post-gas period. Instead, if during the END RAMP function the button is released, the welding cycle immediately terminates and the post-gas period starts. TIG mode with 4T sequence and BI-LEVEL (Fig. O):
  • The first press of the button strikes the arc with current IS. On releasing the button, the current increases according to the START RAMP function up to the welding current value; this value is maintained also with the button released. On each subsequent press of the button (the time that passes between pressing and release must be short), the current will vary between the value set in the BI-LEVEL I1 parameter and the main current value I2.
  • Keeping the button pressed for a long time, the current decreases according to the

END RAMP function up to Bend. The latter is maintained up to release of the button which terminates the welding cycle starting with the post-gas period. Instead, if during the END RAMP function the button is released, the welding cycle immediately terminates and the post-gas period starts.

TIG SPOT and TIG THIN SPOT mode :

  • Welding is carried out by keeping the torch push-button pressed until the pre-set time has been reached (spot time).

MMA WELDING

  • It is most important that the user refers to the maker’s instructions indicated on the stick electrode packaging. This will indicate the correct polarity of the stick electrode and the most suitable current.
  • The welding current must be regulated according to the diameter of the electrode in use and the type of the joint to be carried out: see below the currents corresponding to various electrode diameters:

Ø Electrode (mm)| Welding current (A)

Min.                                                Max.

---|---
|
1.6| 25| 50
2| 40| 80
2.5| 60| 110
3.2| 80| 160
4| 120| 200
5| 150| 280
6| 200| 350

  • The user must consider that, according to the electrode diameter, higher current values must be used for flat welding, whereas for vertical or overhead welds lower current values are necessary.
    As well as being determined by the chosen current intensity, the mechanical characteristics of the welded join are also determined by the other welding parameters i.e. arc length, working rate and position, electrode diameter and quality (to store the electrodes correctly, keep them in a dry place protected by their packaging or containers).

  • The properties of the weld also depend on the ARC-FORCE value (dynamic behaviour) of the welding machine. The setting for this parameter can be made either on the panel or using the remote control with 2 potentiometers.

  • It should be noted that high ARC-FORCE values achieve better penetration and allow welding in any position typically with basic electrodes, low ARC-FORCE values give a softer, spray-free arc typically with rutile electrodes.

The welding machine is also equipped with HOT START and ANTI STICK devices to guarantee easy starts and to prevent the electrode from sticking to the piece.

Procedure

  • Holding the mask IN FRONT OF THE FACE, strike the electrode tip on the workpiece as if you were striking a match. This is the correct strike-up method.

WARNING: do not hit the electrode on the workpiece, this could damage the electrode and make strike-up difficult.

TELWIN-TIG-252-Professional-Inverter-Welder-fig100

  • As soon as arc is ignited, try to maintain a distance from the workpiece equal to the diameter of the electrode in use. Keep this distance as much constant as possible for the duration of the weld. Remember that the angle of the electrode as it advances should be of 20-30 grades.
  • At the end of the weld bead, bring the end of the electrode backward, in order to fill the weld crater, quickly lift the electrode from (CHARACTERISTICS OF THE WELD BEAD – FIG. P).

MAINTENANCE

WARNING! BEFORE CARRYING OUT MAINTENANCE OPERATIONS MAKE SURE THE WELDING MACHINE IS SWITCHED OFF AND DISCONNECTED FROM THE MAIN POWER SUPPLY.

ROUTINE MAINTENANCE

ROUTINE MAINTENANCE OPERATIONS CAN BE CARRIED OUT BY THE OPERATOR.

Torch

  • Do not put the torch or its cable on hot pieces; this would cause the insulating materials to melt, making the torch unusable after a very short time.
  • Make regular checks on the gas pipe and connector seals.
  • Accurately match collet and collet body with the selected electrode diameter in order to avoid overheating, bad gas diffusion and poor performance.
  • At least once a day check the terminal parts of the torch for wear and make sure they are assembled correctly: nozzle, electrode, electrode-holder clamp, gas diffuser.

EXTRAORDINARY MAINTENANCE

EXTRAORDINARY MAINTENANCE MUST ONLY BE CARRIED OUT BY TECHNICIANS WHO ARE EXPERT OR QUALIFIED IN THE ELECTRIC-MECHANICAL FIELD, AND IN FULL RESPECT OF THE IEC/EN 60974-4 TECHNICAL DIRECTIVE. WARNING! BEFORE REMOVING THE WELDING MACHINE PANELS AND WORKING INSIDE THE MACHINE MAKE SURE THE WELDING MACHINE IS SWITCHED OFF AND DISCONNECTED FROM THE MAIN POWER SUPPLY OUTLET.

If checks are made inside the welding machine while it is live, this may cause serious
electric shock due to direct contact with live parts and/or injury due to direct contact
with moving parts.

  • Periodically, and in any case with a frequency in keeping with the utilisation and with the environment’s dust conditions, inspect the inside of the welding machine and remove the dust deposited on the electronic boards with a very soft brush or with appropriate solvents.
  • At the same time make sure the electrical connections are tight and check the wiring for damage to the insulation.
  • At the end of these operations re-assemble the panels of the welding machine and screw the fastening screws right down.
  • Never, ever carry out welding operations while the welding machine is open.
  • After having carried out maintenance or repairs, restore the connections and wiring as

they were before, making sure they do not come into contact with moving parts or parts that can reach high temperatures. Tie all the wires as they were before, being careful to keep the high voltage connections of the primary transformer separate from the low voltage ones of the secondary transformer. Use all the original washers and screws when closing the casing.

TROUBLESHOOTING

IN CASE OF UNSATISFACTORY FUNCTIONING, BEFORE SERVICING MACHINE OR REQUESTING

ASSISTANCE, CARRY OUT THE FOLLOWING CHECK :

  • Check that the welding current is correct for the diamter and electrode type in use.
  • Check that when general switch is ON the relative lamp is ON. If this is not the case then the problem is located on the mains (cables, plugs, outlets, fuses, etc.).
  • The icon is not on, signalling intervention of the safety thermal switch for over or undervoltage or short circuit.
  • Check that the nominal intermittance ratio is correct. In case there is a thermal protection interruption, wait for the machine to cool down, check that the fan is working properly.
  • Check the mains voltage: if the value is too high or too low the welding machine will be stopped.
  • Check that there is no short-circuit at the output of the machine: if this is the case eliminate the incovenience.
  • Check that all connections of the welding circuit are correct, particularly that the work clamp is well attached to the workpiece, with no interferring material or surfacecoverings (ie. Paint).
  • Protective gas must be of appropriate type (Argon 99.5%) and quantity.

GUARANTEE

The manufacturer guarantees proper operation of the machines and undertakes to replace free of charge any parts should they be damaged due to poor quality of materials or manufacturing defects within 12 months of the date of commissioning of the machine, when proven by certification. Returned machines, also under guarantee, should be dispatched CARRIAGE PAID and will be returned CARRIAGE FORWARD. This with the exception of, as decreed, machines considered as consumer goods according to European directive 1999/44/EC, only when sold in member states of the EU. The guarantee certificate is only valid when accompanied by an official receipt or delivery note. Problems arising from improper use, tampering or negligence are excluded from the guarantee. Furthermore, the manufacturer declines any liability for all direct or indirect damages.

CERTIFICATE OF GUARANTEE

Sales company (Name and Signature)

The product is in compliance with:

DIRECTIVES

  • LVD 2014/35/EU + Amdt.
  • EMC 2014/30/EU + Amdt.
  • RoHS 2011/65/EU + Amdt. ErP 2009/125/EC + Amdt.
  • CR 2019/1784/EU + Amdt.

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