Lorch HT 220 AC/DC, used TIG welder

Lorch HT 220 AC/DC from the T series is a single phase TIG AC/DC inverter with an MMA mode. You set the TIG current from 3 to 220 A, the MMA current from 10 to 180 A, and the supply is 230 V from one phase. It weighs about 13 kg and has a housing in class IP23S with a declared resistance to a fall from 60 cm.

What this machine is for

This is a machine for precise TIG welding that fits in a car boot. With alternating current you weld aluminium and its alloys, the description gives thicknesses over 8 mm, with direct current stainless steels and mild steel. The MMA mode adds assembly and repair work, where a covered electrode beats a TIG torch.

The TIG duty cycle at 40°C is 100% at 160 A, 60% at 180 A and 40% at 220 A. In MMA it looks like this: 100% at 120 A, 60% at 150 A and 40% at 180 A. At 160 A in TIG you run a weld without a time limit, which for this class of machine is a good result and lets you work on thicker material without breaks.

A supply from one 230 V phase with a recommended fuse of 16 A means that the machine goes onto a normal workshop socket, and the SinePower Management system also lets you work on a long extension lead and from a generating set. To that comes a weight of about 13 kg, so this is equipment for service, assembly and work at the customer.

With aluminium alternating current is needed. In the positive half period the arc knocks down the layer of oxides, which melts much higher than the metal itself, in the negative half period the fusion goes on. The balance sets the ratio between one and the other, so shifted towards cleaning it picks up dirt from cast sheet, and shifted towards fusion it gives deeper penetration. The frequency narrows or widens the arc and decides how narrow the track on thin sheet will be.

The MACS process models the course of the alternating current so as to limit the amount of heat put into the material. That matters with thin sheets, which with a normal alternating current burn through quickly, and when joining parts of different thickness, where the thinner side heats up faster. Pulse and fast pulse add a second way of controlling the heat and let you hold a narrow, repeatable pool.

In MMA mode the machine gives a current up to 180 A and a 100% duty cycle at 120 A, so it handles typical assembly and repair work. Hotstart makes ignition easier, Anti-Stick protects the electrode from burning, and Arc Force steadies the arc with basic electrodes, which need a short arc. With electrodes up to 4.0 mm in diameter that is a sensible reserve of power for a machine of this weight.

Features and equipment

• TIG AC mode with adjustment of the balance and the frequency and with automatic forming of the electrode tip, the Auto Cap Shape function.
• The MACS process, that is a modulated alternating current, which orders the heat input with thin sheet and when joining different thicknesses.
• Pulse and fast pulse up to 2 kHz, they narrow the arc and limit distortion of the material.
• Contactless HF ignition or Lift TIG by touch, to choose depending on the conditions and on the cleanliness required of the weld.
• SmartBase, a database which picks the arc characteristic for the material and the shielding gas.
• ITC, that is Intelligent Torch Control, recognises the torch connected, the Lorch Powermaster with remote current control from the handle among them.
• SinePower Management, steady work on a long extension lead and with a supply from a generator.
• MMA with the Hotstart, Anti-Stick and Arc Force functions, electrodes from 1.5 to 4.0 mm in diameter.
• BasicPlus panel, simple and synergic, worked to a layout of three steps to welding.
• A reinforced housing with a dust filter, class IP23S and a declared resistance to a fall from 60 cm.
• The option of connecting a foot pedal and remote current controls.

Technical data

What to watch out for

The supply is 230 V from one phase at 50/60 Hz with a recommended fuse of 16 A. The cooling is by air, a WUK 6 or WUK 7 liquid cooler was an option, so for long work at the upper settings you pick a torch for an air circuit or add a cooler. The housing has class IP23S and a dust filter, and the declared resistance to a fall from 60 cm covers transport conditions, not work in the rain.

This unit has a BasicPlus panel. Functions from higher panels, Tiptronic for example, depend on the version of the control, so you confirm the configuration before you buy. The product card gives a current up to 300 A while the maker description gives 220 A, so the data in the shop filter are wider than the real range of the machine. The maker declares that spare parts are available for 10 years from the end of production.

A weight from about 12 to 13.4 kg at dimensions of about 483 x 185 x 325 mm makes it portable equipment, but with TIG work an argon cylinder, a torch and cables come on top. For TIG you need tungsten electrodes, ceramic nozzles and argon together with a regulator and a flow meter, and for MMA an electrode holder with a cable.

How we sell used machines

This unit was checked in our service workshop in Krotoszyn with measurements to PN-EN 60974-4 and a load test. The price includes the first year of the basic service package: an inspection with cleaning of the machine and a validation measurement. Further years can be added. We ship across the European Union, collection in person by appointment.