The EWM Wega 451 is an industrial MIG/MAG power source on a massive transformer, with stepped voltage adjustment and a welding current up to 450 A. The supply is 3 x 400 V, the housing has protection class IP23 and the CE and S marking. A separate four roll feeder tied to the source with an interconnection cable guides the wire, and the liquid cooler sits on the trolley together with the source.
What this machine is for
The Wega 451 was made for the heaviest production jobs and you see it in every design decision. You change the voltage with a knob that switches the taps of the transformer, so the circuit is not sensitive to interference in the mains or to industrial dirt. The lack of inverter assemblies means that grinding dust, temperature swings and dirt in an assembly shop do not shorten the life of the machine. In return you will not change the voltage steplessly: you match the wire feed speed to the 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, and repeating the parameters on the next part comes down to setting the same position of the knob.
A current up to 450 A is a range for thick plate and long welds. The maker pointed to mass production of heavy steel structures, section building of ship hulls, long continuous welds on semi trailers and tippers, large pressure tanks and farm silos, repairs of heavy construction equipment made of thick plate, mechanised production with very long interconnection cables and repeatable joining of thin sections by spot welding. At such currents liquid cooling is not an extra but a condition of the work: the pump forces fluid through the interconnection cable and the torch, taking heat off the torch, so the contact tips do not start to melt during a long arc.
The second characteristic feature is the separate feeder. The interconnection cable between the source and the feeder widens the working zone of the welder by its own length, which in assembly of large tanks and in work at height saves dozens of moves of the equipment. The documentation gives work with torches even 5 metres long, because the four roll drive manages to push the wire through such a long liner without jams. In mechanised production the same layout works with very long interconnection cables, which lets you put the source outside the working zone and not move it together with the bay.
Features and equipment
- Massive transformer block with stepped voltage adjustment: the knob switches the taps, and the circuit stays insensitive to mains interference and industrial dirt.
- Welding current up to 450 A: reserve for thick steel parts and for long multi shift work.
- Separate four roll feeder in a steel housing: every roll pushes the filler, so the pressure spreads evenly, the wire does not slip or deform, also with long torches and cored wires.
- Interconnection cable between the source and the feeder: the working zone of the welder grows by the length of this cable, which matters on tanks and in work at height.
- Work with torches even 5 metres long: the four roll drive pushes the wire through a long liner without jams.
- Integrated liquid cooler in the lower part of the trolley: a rotary pump forces fluid through the interconnection cable and the torch, protecting the contact tips against melting at 450 A.
- 2T mode: the arc burns as long as you hold the trigger, which gives control on short tack joints.
- 4T mode: one press and release of the trigger keeps the cycle going, so on welds many metres long on pipelines and semi trailer rails the hand does not work statically.
- Adjustment of the wire burn back time: after you release the trigger the voltage holds for a fraction of a second more and burns off the excess wire, so the filler does not stick into the freezing pool, and the tip is ready for the next strike without cutting.
- Spot welding cycle: a timer circuit puts the arc out after a set time despite the trigger being held, so every spot has the same energy, the same depth of fusion and the same look.
- Stitch welding cycle: the control breaks and restarts the current in a cycle, and the cooling pauses limit stresses and warping of long sections and of fillet welds.
- Housing in class IP23 with the CE and S marking: a construction allowed for work in conditions of a raised risk of electric shock, for example in tight enclosed spaces.
- No inverter assemblies: grinding dust, temperature swings and industrial dirt do not shorten the life of the power circuit, and the bay goes for service less often.
Technical data
| Brand | EWM |
|---|---|
| Type | transformer welder, modular |
| Mains supply | 3 x 400 V |
| Maximum welding current | 450 A |
| Welding processes | MIG/MAG |
| Type of voltage adjustment | stepped, transformer |
| Feeder build | separate, 4 roll |
| Torch cooling system | liquid, built in cooler |
| Housing protection class | IP23 |
| Safety marking | CE / S |
What to watch out for
The supply is 3 x 400 V, so the machine needs a power connection with protection matched to a current of the order of 450 A. The set with the source, the feeder, the cooler and the trolley is heavy, plan moving it around the plant with a truck. The product data sheet does not give the duty cycle at the maximum current, so treat 450 A as a peak value and on long welds go lower or plan breaks.
The cooling system works only on approved fluid, you check the level in the tank regularly, and the torch has to be made for water. The interconnection cable needs protection against being run over and a check from time to time, because in sets of this type it is the part that fails most often. The stepped adjustment does not change the voltage while the arc burns, on very thin sheet that is a limit. The 4T mode suits a series of short tacks less, 2T is handier there. Correct the wire burn back time after every bigger change of the current or the feed, otherwise the tip of the wire is left with a ball or sticks into the pool. The spot cycle does not let you lengthen a single spot once the trigger is pressed, and the stitch mode lowers the welding speed in exchange for smaller distortion. The reach of the welder ends at the length of the interconnection cable, so settle that length before you buy.
This unit is sold
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