Kemppi Kempact 253R is a compact three phase inverter MIG/MAG welder with a four roll DuraTorque feeder built into the housing. The documentation gives 250 A at a 40% duty cycle and 150 A at a continuous 100% load, with a 3 x 400 V supply. The letter R stands for the Regular version, that is manual and independent settings of voltage, wire speed and arc dynamics.
What this machine is for
This is a source for a metalwork shop, a medium sized production plant, a repair service and a body shop. You set the current from 20 A at 10 V to 250 A at 31 V, so you cover both thin panels and structural sections. The machine welds mild steel under pure CO2 or argon mixtures with wires from 0.8 mm to 1.2 mm, CrNi stainless steel with wires from the Ss group, and after a change of polarity in the feeder compartment also flux cored and metal cored wires. Braze welding of galvanised sheet you do with CuSi or CuAl filler from 0.8 mm to 1.0 mm in diameter.
On typical metalwork jobs, that is frames, railings, gates and fences in mild steel, you reach for wires from 0.8 mm to 1.2 mm and the middle of the setting range. In repair services the reach counts: the MIG torch is 5 m and the earth cable is 5 m as well, so you walk around a farm machine or a vehicle without moving the source. In a body shop you work with the spot mode and the Hot Spot function, which keep the heat put into thin sheet in check, so the panel ripples less. On repairs after a collision the CYCLE mode with a pause from 0.1 s to 3 s gives a stitch weld that joins parts without pulling the geometry of the part.
The R version has no synergic programs and no pulse. You set the voltage and the wire speed yourself, with two knobs, and the third one handles arc dynamics. For an experienced welder that is an advantage, because you set the working point exactly for the material and the gas, without correcting a ready curve. The machine will also pull aluminium with wire from 1.0 mm to 1.2 mm, but it needs the wire path changed over: rolls with a U groove and a PTFE or graphite liner, because with a 5 m torch soft wire coils up easily.
Features and equipment
- Four roll DuraTorque feeder built into the housing: the pressure is spread over a larger area of the wire, so the filler neither slips in the rolls nor gets crushed, also with steel wires of 1.0 mm and 1.2 mm and with cored wires.
- Arc dynamics adjustment on a scale from -9 to +9: negative values slow the rise of the short circuit current and give a soft arc with a fluid pool for steel and gas mixtures, positive values speed the rise and cool the arc, which helps in forced positions and under pure CO2.
- SPOT mode: it counts the arc time from 0.1 s to 9.9 s, so assembly spots come out repeatable.
- CYCLE mode: stitch welding with a pause from 0.1 s to 3 s, it limits the heat put into thin body panels.
- Hot Spot function, started by holding the selection button longer: local heating of the sheet to take out stress after welding or after a collision, without a gas torch.
- WireLine service indicator: the circuit watches the resistance in the wire feed path and lights a spanner icon when the liner in the cable has to be cleaned, the contact tip changed or the spool brake adjusted. The signal does not stop the work.
- A spool compartment for spools up to 300 mm in diameter and up to 20 kg: fewer breaks to change filler on longer runs.
- Change of polarity in the feeder compartment: you switch the machine to flux cored and metal cored wires without extra adapters.
- MIG torch of 5 m with a Euro connection and an earth cable of 5 m: a working radius around the source without moving the trolley.
- Integrated trolley with a rear platform for the gas cylinder: the cylinder travels with the source, without disconnecting the hose.
- Housing with protection class IP23S and class F insulation: the electronics take workshop conditions, and at rest the machine takes rain falling at an angle up to 60 degrees.
- Wire feed speed range from 1.0 m/min to 18.0 m/min and arc voltage from 8.0 V to 31.0 V: the settings go low for thin sheet and high for thicker sections.
- Open circuit voltage of 41 V: the arc strikes surely also when the surface of the part is slightly tarnished or covered with scale.
- Three separate knobs instead of a menu: you change the voltage, the wire speed and the dynamics in gloves, without going into screens, so correcting parameters during a run takes seconds.
- A draw of 8.5 kVA and 11.9 A at full load: the machine fits a typical workshop circuit with a type C 10 A fuse, without rebuilding the switchboard.
Technical data
| Brand | Kemppi |
|---|---|
| Type | inverter MIG/MAG welder, manual control |
| Supply voltage | 3 x 400 V, tolerance 15%, 50/60 Hz |
| Welding current in the product record | up to 300 A |
| MIG/MAG welding current range | from 20 A at 10 V to 250 A at 31 V |
| Current at a 40% duty cycle and 40°C | 250 A |
| Current at a continuous 100% load | 150 A |
| Open circuit voltage | 41 V |
| Wire feed speed range | from 1.0 m/min to 18.0 m/min |
| Arc voltage adjustment range | from 8.0 V to 31.0 V |
| Power and current draw at maximum load | 8.5 kVA, 11.9 A |
| Recommended mains fuse | type C 10 A |
| Feeder mechanism | 4 roll DuraTorque |
| Maximum wire spool | diameter 300 mm, weight 20 kg |
| Wire diameters | from 0.8 mm to 1.2 mm |
| Protection and insulation class | IP23S, class F |
| Source weight without cables | 44 kg |
| Cooling | gas |
| Functions | SPOT, CYCLE, Hot Spot, WireLine, arc dynamics adjustment |
What you get
- Kemppi Kempact 253R source with a built in four roll DuraTorque feeder
- transport trolley with a platform for the gas cylinder
- MIG welding torch of 5 m with a Euro connection
- earth cable 5 m with a clamp
What to watch out for
The machine needs a 3 x 400 V supply at 50/60 Hz with a 15% tolerance, and the manufacturer recommends a type C 10 A fuse. The draw at full load is 8.5 kVA and 11.9 A, so a workshop circuit is enough. The torch is cooled by gas, not by liquid, so on long beads at high current watch the temperature of the handle and the nozzle. Plan the duty cycle by the figures from the documentation: you get 250 A at 40%, and without breaks the machine gives 150 A. The product record puts this unit in the band up to 300 A, the model documentation speaks of 250 A, so confirm the configuration before you buy.
The source weighs 44 kg without cables and accessories, and with the cylinder on the platform you roll the set across the floor, but you carry it into a vehicle with two people. Class IP23S allows rain falling at an angle up to 60 degrees while the machine stands, it does not allow washing with a jet. The R version has no synergy and no pulse, so you set the parameters by hand, and for aluminium you need U type rolls and a PTFE or graphite liner.
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.
