Lorch T 300 AC/DC Portable TIG Welding Machine

Portable three-phase AC/DC TIG inverter rated to 300 A

The Lorch T 300 AC/DC is the largest model of the Lorch T series, a family of compact and lightweight TIG inverters that are carried on a shoulder strap (included in delivery) or by the handle. It runs on a three-phase 400 V supply with a 16 A fuse and CEE 16 plug, delivers a TIG range of 5 to 300 A, and also welds stick electrodes from 1.5 to 5.0 mm. In AC mode it welds aluminium and aluminium alloys; in DC it covers steel, stainless steel and other weldable metals.

Two operating concepts are offered. BasicPlus has a digital ampere display, pulse function, remote control connection and illuminated symbols for the welding sequence. ControlPro, shown in the photo, adds a digital volt-ampere display, more detailed welding sequence control and Tiptronic job memory for 100 welding tasks. Both follow Lorch’s “3 steps to weld” concept.

Technical specifications

T series models compared

Every size is available as a DC system and as an AC/DC system with the same 483 x 185 x 325 mm housing.

Typical applications

A portable 300 A AC/DC unit is a common choice for maintenance teams and site fabricators who move between aluminium repairs, stainless piping and steel structures and need one machine for all of them. The 200 A continuous rating in both AC and DC handles fill and cap passes on medium-wall material, while the light case can be carried up scaffolding or into a vessel. A remote control can be connected for adjusting current away from the machine. For higher continuous output on a wheeled chassis, see the

Lorch V 30 AC/DC.

Choosing between the DC and AC/DC system is mainly a question of materials: if aluminium or magnesium will never be welded, the DC system is sufficient for carbon steel, stainless steel, copper alloys and titanium. If aluminium repairs are likely, even occasionally, the AC/DC version avoids the need for a second machine. Because the T 300 runs on a 16 A three-phase circuit, it can usually be plugged into standard site distribution boards and suitably rated generators.

Documents and quotation

Technical data for the T 180, T 220, T 250 and T 300 is available via the Datasheet & Documentation link below. For a quotation, state DC or AC/DC, BasicPlus or ControlPro, torch type and length, and whether a remote control is needed. Other machines are listed under TIG welding machines.

Typical applications in Oman & the GCC

In Oman and the GCC, the T 300 AC/DC is well suited to maintenance and shutdown teams in oil & gas, petrochemical and power plants, to aluminium boat and marine repair, and to fabrication of stainless food, water and pharmaceutical piping. At 14.5 to 16.3 kg it can be carried onto scaffolding and into plant areas where a wheeled machine cannot go.

Selection checklist

• Materials: does the shop weld aluminium or magnesium? If so, AC/DC is needed. If not, a DC system is enough.
• Thickness and duty: compare the duty-cycle figures at the currents you will actually use, not only the maximum current.
• Torch: choose gas cooling for lighter work and water cooling for long arc-on times at high current.
• Control: decide between the basic operating concept and the version with job memory, which helps when several welders repeat qualified procedures.
• Accessories: foot or hand remote control, earth cable, gas regulator, tungsten electrodes and filler rods.

TIG best practice

Grind tungsten electrodes lengthwise and use a size that suits the current range. Use pure argon shielding gas for most TIG work, with a flow rate set for the nozzle size and any draughts. Clean aluminium with a dedicated stainless brush and solvent just before welding, because the oxide layer re-forms quickly. On stainless steel and titanium, back purging and trailing shields protect the root and heat-affected zone from oxidation.

Power supply in Oman & the GCC

Lorch rates its machines for 3~ 400 V, 50/60 Hz, ±15%. That matches the 400/415 V, 50 Hz three-phase industrial supply used across Oman and most of the GCC. When the machine runs from a generator on site, check that the generator is sized for inverter loads and has stable voltage regulation.

Working in high ambient temperatures

Welding duty cycles are measured under the conditions set out in EN 60974-1. Summer shop and site temperatures in the Gulf often run higher than this, so plan for some reserve capacity. Keep the cooling air inlets clear of dust and sand, and blow out the machine regularly with dry compressed air while it is disconnected from the mains. Where a water cooling unit is fitted, top it up with the coolant the manufacturer specifies and check the level often.

Why source from Seven Star LLC

Seven Star LLC supplies Lorch TIG welding equipment across Oman and the GCC. Tell us your application, materials and site conditions and our team can help confirm the correct ordering code and accessories before you request a quote.