Migatronic Pi 400 AC/DC with a CWF feeder is an industrial TIG source for alternating and direct current, liquid cooled, with an external cold wire feeder. You set the welding current from 5 to 400 A, at a 60% duty cycle the machine gives 400 A, and the supply is 3 x 400 V with a 15% tolerance.
What this machine is for
With alternating current you weld aluminium and its alloys, with direct current acid resistant steels, duplex steels and austenitic steels. The range from 5 to 400 A goes down to thin sheet and reaches thick sections, and a cycle of 400 A at 60% at an ambient temperature of 40 degrees Celsius lets you hold a high current through most of a shift. The source works continuously on aluminium from 10 to 15 mm thick and thicker.
The CWF feeder, that is the Cold Wire Feeder, feeds filler from a separate spool, so you do not guide the rod by hand. The wire moves in time with the pulse of the source, so the weld has an even bead over its whole length, and the operator tires less on long runs. You take such a layout for pipelines in acid resistant and duplex steels, for serial production of fuel tanks, road tankers and aluminium stage structures, and everywhere the welds are long and are meant to look the same.
The machine also suits as a base for a mechanised station. You connect it to a welding positioner or to a simple longitudinal automat, because the wire feeding and the arc parameters come from one control. With the feeder disconnected you have an ordinary 400 A TIG source for manual work.
Features and equipment
- The CWF system, that is a cold wire feeder integrated with the digital control of the Pi 400 source. You set the feed speed in metres per minute, and you set the delay of the wire start and stop against the arc separately. The feeding stays even over the whole weld, which matters on pressure structures, where uneven filler shows up in the tests.
- Synchronisation of the feed with the current pulse, described by Migatronic as Synergy Pulse. The wire reaches the pool at the moment of the current peak, so it fuses evenly and does not freeze the pool. The manufacturer gives a welding speed higher by 40 to 60% than guiding the rod by hand.
- D.O.C, that is Dynamic Oxide Control. The circuit reads the arc as it goes and picks the polarity so that the cleaning zone when welding aluminium with alternating current is narrow but wide enough to break the aluminium oxide. A narrower cleaning zone means a smaller heat affected zone and less distortion of the sheet, and the manufacturer gives a rise in aluminium welding speed of up to 30%.
- IGC, that is Intelligent Gas Control. The shielding gas flow changes together with the current and the phase of the process, without the gas surge at the strike that draws air into the welding zone. The manufacturer gives gas use lower by up to 50%.
- TIG-A-Tack for tacking. Short pulses of high current melt the edge without putting heat deep into the material, so tack spots in austenitic and acid resistant steels are almost invisible and need no grinding before the welding proper.
- Synergy PLUS. You set the main current, and the circuit picks the base current, the pulse duration and the frequency. In the alternating current mode it adds the balance and the zero crossing frequency.
- IGC work on aluminium watches the shield at the start and when filling the crater, so there are fewer gas pores at the beginning of the weld and less risk of a crack at its end.
- Integrated MCU cooler with a liquid circuit for the torch.
- Modular build of the feeder. You disconnect the CWF and work with classic TIG, although the control of this unit was set for work with the feeder.
Technical data
| Brand | Migatronic |
|---|---|
| Current type | AC/DC |
| Processes | manual welding, special processes |
| Supply voltage | 3 x 400 V, tolerance 15% |
| TIG welding current | from 5 to 400 A |
| Duty cycle at 40 degrees Celsius | 400 A at 60% |
| Wire feeding system | external CWF, Cold Wire Feeder |
| Mains fuse | 25 A |
| Cooling | liquid, integrated MCU cooler |
| Open circuit voltage | 95 V |
| Protection class | IP 23 |
| Aluminium thickness in continuous work | from 10 to 15 mm and more |
What you get
- Migatronic Pi 400 AC/DC source
- CWF cold wire feeder
- cooler
- torch
What to watch out for
The supply is 3 x 400 V with a 15% tolerance and a 25 A mains fuse, so the connection has to be industrial and not a workshop socket on an extension lead. The open circuit voltage is 95 V, the housing has class IP 23, that is work under a roof. The cooling runs on liquid in the closed circuit of the MCU cooler, so before the start check the fluid level, the flow in the torch hoses and the work of the pump. A torch without flow is destroyed in seconds, and an air locked circuit gives breaks in the cooling.
The source with the cooler and the feeder is a heavy and large set, so plan a fixed station, transport on a pallet and room for the wire spool. The CWF feeder is modular, but the control of this unit was set for work with an automat, so after going over to manual welding the parameters have to be arranged again. For a complete mechanised station add a positioner or a longitudinal carriage, because the machine does not guide the torch itself. Choose the wire for the feeder to suit the material and the diameter, and at a spool change check the guides and the rolls. Before dispatch we will show you photos of the panel and the feeder.
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.
