EWM TETRIX 351 SYNERGIC KD/HD HotWire, used TIG welder

EWM Tetrix 351 Synergic KD/HD HotWire is an industrial TIG DC and MMA DC source that gives 350 A at a 100% duty cycle, that is without breaks for cooling down. You set the current from 5 A to 350 A, the supply is 3 x 400 V at 50/60 Hz, and the integrated liquid cooling module has a power of 1500 W and a tank of about 12 l. This is a project build marked ART 090-S00118-02110 with the number PROJ 552735, prepared at the factory for cold KD and hot HD wire feeding.

What this machine is for

The source works only with direct current, so it handles CrNi stainless and acid resistant steels, unalloyed and low alloy Fe/St steels, copper and its alloys, brasses and CuZn bronzes, and in the Spez program also titanium and nickel alloys. Aluminium is out, because breaking the oxide layer needs alternating current, that is a TIG AC/DC source. The arc burns steadily from 5 A, so the same machine lays a root run on a thin tube and a filling pass on a thick tank wall.

A cycle of 350 A at 100% and an ambient temperature of 40°C is the main argument of this design. The power block has oversized copper busbars and a high output heat exchanger, so you run long welds on thick walls without stops. The machine goes to the production of pipelines and process installations, to pressure vessels and to the chemical, pharmaceutical and food industry, where repeatable parameters are required by the WPS and WPQR procedures.

The KD/HD marking says that inside there are interfaces and buses for integration with mechanised wire feeding systems: cold wire (Kaltdraht) and resistance heated hot wire (Heissdraht, HotWire). The control modules plug the source into wire feeding stations and automatic stations. The feeder itself and a torch with filler guiding are not part of the set, the machine only has the factory circuit preparation.

Features and equipment

• EWM activArc, dynamic control of arc power: when the arc gets shorter or longer the circuit corrects the current and the voltage at once, holding a steady heat input, so the tungsten does not stick to the pool and the penetration stays even.
• TIG pulse in three modes: the automatic one picks the frequency and the balance itself, the thermal one with a frequency in the order of seconds shapes the ripple and holds the liquid metal in forced positions, the metallurgical one up to 15 kHz focuses and stiffens the arc, so the heat affected zone is narrower and thin sheet distorts less.
• spotArc: repeatable, flat tack spots in a fraction of a second, with a small heat input, without distortion and discolouration.
• Spotmatic: you strike the tacking arc with a short touch of the electrode on the material, without reaching for the torch button, which speeds up the assembly of a series.
• TIG Synergic with a base of material programs: after you point to the electrode diameter from 1.0 mm to 4.0 mm, the material (CrNi, Fe/St, Cu, CuZn, Spez) and the joint geometry, the circuit sets the start, the slope up, the slope down, the crater current and the gas flow, and leaves the manual correction to you.
• Contactless HF ignition and contact LiftArc ignition: you pick a start without touching the material or one without a high frequency pulse, depending on the surroundings.
• 2T and 4T cycle with a second current I2: you switch the lowered secondary current on with the torch button, which helps when you come to the edge of a part, at a change of wall thickness and when filling the crater.
• MMA DC up to 350 A with Hot Start, Arc Force and Anti-Stick: basic electrodes start more surely, the arc holds at a deep penetration, and on a short circuit the system protects the electrode from overheating.
• MMA with pulsed current: it helps when you work in forced positions.
• Integrated liquid cooling circuit: a power of about 1500 W at a flow of 1 l/min, a tank of about 12 l, a maximum flow of 5 l/min and a pressure up to 3.5 bar.
• TIG torch type 18 of 8 m, liquid cooled: a large working radius around a pipeline or a structure, without moving the source.
• Four wheel trolley with a cylinder shelf and lifting eyes: you roll the station across the floor or lift it with a crane.
• An efficiency of about 90% at a power factor of 0.99: the input current reaches only 21.7 A.

Technical data

What you get

• EWM Tetrix 351 Synergic KD/HD source with an integrated liquid cooling module
• TIG torch type 18 of 8 m, liquid cooled
• earth cable 4 m with a clamp
• supply cable 4 m
• four wheel workshop trolley with a gas cylinder shelf and lifting eyes

What to watch out for

The machine needs a 3 x 400 V mains at 50/60 Hz with a tolerance from -25% to 20%, and at an input current of 21.7 A the manufacturer recommends a C 25 A or C 32 A fuse. The cooling module has a power of about 1500 W and a tank of about 12 l, so check the level and the cleanliness of the fluid before the start, because work at 350 A without breaks loads the torch with no moment of rest. The open circuit voltage is 79 V DC, so in tight and damp spaces keep to the safety rules for industrial sources. The platform on the trolley weighs from about 131 kg to 135 kg and measures about 1100 x 455 x 1000 mm, so you roll it across the floor, but for a vehicle you need a lift.

The KD and HD preparation is made at the factory, while an external wire feeder and a torch with filler guiding are not part of the set, you buy them separately and then confirm that the interfaces match. The source gives direct current only, so you leave aluminium to a TIG AC/DC machine. A torch of 8 m gives a large reach, but at such a length watch the bending radius of the package and the flow in the coolant circuit.

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.