The EWM Wega 330A is an industrial MIG/MAG welder based on a transformer with stepped voltage adjustment, with a welding current up to 330 A. The supply is 3 x 400 V, the housing has protection class IP23. A four roll feeder guides the wire, and on the panel you have 2T and 4T modes, adjustment of the wire burn back and spot and stitch cycles.
What this machine is for
The Wega 330 is a source for series joining of steel in conditions in which electronics have a short life. The voltage adjustment goes through physical switching of the winding taps, so the arc is stable and the machine does not react to electromagnetic interference in the shop. The lack of microprocessor circuits means resistance to grinding dust, damp and sudden temperature swings in the shop. The price for that is the lack of stepless adjustment: you match the wire feed to the voltage step you pick, and not the other way round. In practice the operator learns a few pairs of settings for the usual thicknesses and comes back to them through the whole shift, which with repeatable production does not get in the way, and with a constant change of parts is sometimes a nuisance.
The maker pointed this model to workshops, heavy industry and production of steel structures. The applications listed are series production of medium and heavy structures in carbon steel, metalwork and smithing, repairs and reclamation of frames of trucks and semi trailers, assembly of railings, gates and industrial fencing, tight joints in low pressure tanks and silos, service of construction equipment and farm machines and short tack welds in prefabrication.
The operation is simple and that is an advantage here. You pick the settings with a switch and a knob, so training a new worker takes little time, and coming back to proven parameters comes down to setting the same position. In production of repeatable parts that means fewer setting mistakes than on a machine with a broad menu. You have to remember that each of the modes has its own area: 4T gives comfort on a long weld, but with fast tacking you control the start and the end less precisely than in 2T, and the stitch mode lowers the speed of work in exchange for smaller distortion. The spot cycle in turn does not let you change the set time while a single spot lasts, so you set that parameter before a series, not during it.
Features and equipment
- Transformer block with multi step voltage adjustment: switching the taps of the primary winding gives a stable arc and no sensitivity to the electromagnetic interference that in a shop can put inverter circuits out of tune.
- Construction without sensitive electronics: the machine takes dust, damp and temperature swings, and a repair comes down to simple assemblies, not to changing a control module.
- Welding current up to 330 A: reserve for medium and thicker structures in carbon steel.
- Four roll wire feed mechanism in the spool chamber: four driven wheels press the filler over a larger area than a two roll layout, so the wire does not slip and does not get crushed during the long transport through the torch, and the arc burns evenly, without cold laps and without excessive spatter.
- Handling of wires of larger diameters and of soft fillers: a four roll layout is the condition of work here, because aluminium and cored wire do not take pressure at two points.
- 2T mode: pressing the trigger strikes the arc, releasing it breaks the process at once, which gives an advantage on short tack welds and in fast spot work.
- 4T mode: a short press and release of the trigger starts the welding, so the hand does not hold the button through the whole weld, and the muscles of the forearm tire less on long beads on tanks and pipes.
- Adjustment of the wire burn back time: the voltage is cut off later than the feed stops and burns off the excess wire, so the tip does not stick to the cooling pool and does not weld itself to the copper contact tip, and before the next strike you do not have to cut off a ball.
- Spot welding cycle with a timer: the machine ends the arc after a set time whatever the trigger is doing, so every tack weld gets the same energy, has the same fusion and the same look, which limits burn through of thin sheet in panel work and on ventilation ducts.
- Stitch welding cycle: the current switches on and off at even intervals, the material cools in the pauses, so the stresses and the distortion of thin parts are smaller, and the heat affected zone is narrower when you join parts of different wall thickness.
- Housing in class IP23 with the CE and S marking: a construction allowed for work with a raised risk of electric shock.
Technical data
| Brand | EWM |
|---|---|
| Type | transformer welder |
| Supply | 3 x 400 V |
| Maximum welding current | 330 A |
| Welding methods | MIG/MAG |
| Type of voltage adjustment | stepped, transformer |
| Wire feeder mechanism | 4 roll |
| Cooling | gas or an integrated cooler, depending on the build |
| Housing protection class | IP23 |
| Safety marking | CE / S |
What to watch out for
The supply is 3 x 400 V, the protection class is IP23, the marking is CE and S. The product data sheet gives liquid cooling, and the documentation of the maker allows a gas version or one with a cooler, depending on the build, so before you pick a torch confirm which layout this unit has. That is the most important question with this model, because the purchase of the torch and the cables depends on it. A liquid cooled torch connected to a machine without a cooler you will damage in a few seconds, and a gas cooled torch in long work at a high current heats up faster than the operator can take a break.
The stepped adjustment does not let you correct the voltage while the arc burns, when the material thickness changes you stop and move the switch. The drive rolls and the liner are matched exactly to the diameter and the type of wire, otherwise a four roll feeder gives no advantage. The wire burn back time has to be corrected after a bigger change of the feed and the voltage. A transformer construction weighs its own and draws more from the mains than an inverter of similar current, plan the transport around the plant with a truck. Class IP23 allows work under a roof, but not in open rain. The product data sheet does not give the duty cycle at the maximum current, so on long welds treat 330 A as a peak value, not a continuous one.
This unit is sold
This machine has already gone to a customer. Similar units are listed below, and if you want the same model, leave your contact details in the form and we will let you know when the next one arrives.