The Kemppi Kempoweld 4000W is a stepped MIG/MAG power source on a transformer, with a built in liquid cooler. The maximum current is 400 A, and the duty cycle at a temperature of 40 °C is 400 A at 45% and 270 A at 100%. You set the voltage in 40 steps, and the supply is 400 V three phase.
What this machine is for
This is a power source for thick sections in multi shift work: steel structures, shipbuilding and bridge industry, heavy farm and construction machines, overhauls and rebuilding of working parts of excavators and bulldozers, steel vessels with a thick wall. The letter W in the name means a factory liquid cooling circuit, thanks to which the torch takes work at high parameters and with wires up to 1.6 mm in diameter.
A transformer with copper windings takes surges in the mains and high thermal loads. The lack of IGBT power transistors means the machine does not react to metal dust in the hall, and service comes down to cleaning the cooling circuit and checking the contacts of the voltage switches. The price is the high weight and the need to change the voltage steps by hand, because there is no synergic control here.
Voltage adjustment covers 40 steps, laid out as four coarse ranges of ten sub ranges. Such a dense grid lets you match the arc energy to the material thickness and hold a narrow heat affected zone. You change the arc dynamics by hand, moving the earth cable between three choke sockets: from a hard arc with deep fusion to a soft one with less spatter, depending on the steel grade and on whether you work in CO2 or in an Ar/CO2 mixture.
The power source works with a separate wire feeder, for example the Wire 400 with a 4 roll drive. You move the feeder a dozen or so metres away from the machine, depending on the length of the interconnection cable, so you walk around a large structure without rolling the whole set. After you fit the feeder with U groove rollers, a teflon liner and argon, the machine will also pull thick aluminium parts with the MIG process.
Features and equipment
- Transformer with copper windings: resistance to surges and thermal loads, work in a hall with heavy dust.
- Voltage adjustment in 40 steps, four ranges of ten sub ranges: exact matching of the arc energy to the material thickness.
- Three step inductance adjustment on the choke sockets: you move the earth cable and change the arc characteristic from hard to soft.
- Built in liquid cooler in the lower part of the power source: it lowers the centre of gravity and takes the heat from the torch, which lets you work with wires up to 1.6 mm at high currents.
- Duty cycle 400 A at 45% and 270 A at 100%: a reserve for thick welds and work with no limit at a lower current.
- Work with the separate Wire 400 feeder with a 4 roll drive: a reach of a dozen or so metres from the power source, depending on the cable package.
- Protection class IP 23C.
Technical data
| Brand | Kemppi |
|---|---|
| Model | Kempoweld 4000W |
| Type | stepped MIG/MAG power source on a transformer |
| Supply | 400 V, 3 phases, 50 or 60 Hz |
| Maximum welding current | 400 A |
| Duty cycle 45% at 40 °C | 400 A |
| Duty cycle 100% at 40 °C | 270 A |
| Number of voltage steps | 40, in a four times ten layout |
| Inductance adjustment | three step, choke sockets |
| Maximum wire diameter | 1.6 mm |
| Torch cooling | liquid, integrated cooler |
| Feeder | separate, for example Wire 400, 4 roll |
| Protection class | IP 23C |
What to watch out for
The supply is 400 V three phase at 50 or 60 Hz. A 45% duty cycle at 400 A gives four and a half minutes of welding in a ten minute window, work with no limit starts at 270 A, and the values are given for an ambient temperature of 40 °C. The adjustment is stepped, so you will not change the voltage while the arc burns, and there is no synergic control here, so you pick the wire speed yourself.
The liquid cooler sits in the power source, so the torch has to be liquid cooled, and you change the fluid made for welding coolers from time to time, so that scale does not settle in the circuit. The data sheet lists neither a feeder, nor a torch, nor an interconnection cable, so confirm the accessories before you buy, because without a feeder the power source does not work. The transformer design is heavy, and you need a trolley to move it.
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.