Rehm Mega Puls 400 Push-Pull is a processor controlled MIG/MAG power source with pulse and double pulse, with liquid cooling. You set the current steplessly from 5 to 400 A, the duty cycle at 40 °C is 400 A at 60% and 310 A at 100%. The supply is 3 x 400 V with a tolerance of 15%, and the source has its own digital interface for the Push-Pull drive.
What this machine is for
This is a source for aluminium and high alloy steels, where a stable pulsed arc and heat control count. The controller corrects current and voltage on the fly, reacting to changes in the distance from the wire to the pool, so the arc does not run away when the stick out changes. The maker aimed the machine at the building of yachts and vessels with welded aluminium hulls, at makers of rail vehicle bodies, tankers and truck bodies, at the prefabrication of process equipment in acid resistant stainless steel, at power engineering with support structures and heat exchangers, and at repairs and hardfacing of parts of construction machines.
The Push-Pull interface solves the problem of feeding soft wires. The motor in the feeder runs in step with the motor in the torch handle, so the wire runs evenly also with cable assemblies from 8 to 10 m long and with a bent hose. That matters with aluminium wires 1.0 mm and 1.2 mm in diameter, which because of their low stiffness jam in the liner of a normal 4 roll drive. The synchronisation works in a closed loop, so when feed resistance rises the system stops the process instead of grinding the wire in the rolls.
The pulse orders metal transfer across the arc. Instead of random short circuits and spatter the droplet detaches in the rhythm of current pulses, one per pulse, so the weld is clean and you hold the heat put into the material in check. On aluminium that counts twice: the alloy carries heat away quickly, but it also loses stiffness quickly at raised temperature, so an excess of energy warps the part and weakens the joint. Double pulse adds a slow modulation which lays the face in a regular ripple and helps bridge assembly gaps.
A large working radius changes how the station is organised. The heavy source stays in place and the welder walks around a large structure with the torch on a long cable assembly, without moving the machine every few metres. The machine also handles standard feeding, so for carbon steel you use a normal feeder.
Features and equipment
- Digital Push-Pull interface: it synchronises the feeder motor with the motor in the torch handle, so the wire feed speed is steady whatever the bends in the hose, and the wire does not slip in the rolls.
- Work with long cable assemblies, from 8 to 10 m: a working radius around a large structure without moving the source.
- MIG/MAG Puls: droplet transfer in the peak phase of the pulse, without short circuits, with less spatter and control of the heat put into the material.
- Double Puls, that is double pulse: it lays a regular, rippled face close to a TIG bead at the output of the MIG/MAG method, useful on aluminium and on acid resistant stainless steel.
- FOCUS.PULSE: it narrows the arc column, so penetration is deeper and the heat affected zone narrower. A narrow arc makes welding easier in tight grooves and fillet welds and limits thermal distortion on thicker aluminium.
- SDI, that is stepless electronic inductance adjustment: you set the arc characteristic from soft to hard by controlling how fast the current rises in the short circuit phase. On stainless steel it gives a smooth face, on aluminium it helps hold the pool out of position.
- POWER.PULSE: it raises the deposition rate, so you lay long fillet welds faster with less total heat put into high strength steel.
- Built in liquid cooling system: it takes heat from the torch when you work at 400 A, so the handle and the wear parts last longer.
- Correction of parameters in real time: the control system reacts to changes in the distance from the wire to the pool, so the arc holds with a changing stick out and out of position.
- Stepless current adjustment from 5 to 400 A: you go down to thin sheet and come back to full current without changing equipment.
- Support for standard feeding and for Push-Pull: one source for two kinds of feeding equipment.
Technical data
| Brand | Rehm |
|---|---|
| Type | processor controlled MIG/MAG power source with pulse and double pulse |
| Maximum welding current | 400 A |
| Duty cycle at 40 °C | 400 A at 60%, 310 A at 100% |
| Current adjustment range | from 5 to 400 A, stepless |
| Supply voltage | 3 x 400 V with a tolerance of 15% |
| Feeding systems supported | standard, Push-Pull, digital interface |
| Aluminium wire diameters given by the maker | 1.0 mm and 1.2 mm |
| Recommended cable assembly length | from 8 to 10 m |
| Cooling | liquid, built in system |
| Processes | MIG/MAG, Puls, Double Puls, FOCUS.PULSE, POWER.PULSE |
What to watch out for
The machine needs a 3 x 400 V connection, and the voltage tolerance reaches 15%. A 60% duty cycle at 400 A gives six minutes of welding in a ten minute window, work without a limit starts at 310 A, and the values are given for an ambient temperature of 40 °C. In a warmer hall the thermal cut out acts sooner.
Liquid cooling is built into the source, so after delivery you check the fluid level, the tightness of the quick couplings and the flow in the circuit. The Push-Pull torch is a separate item with its own motor in the handle, and the product card lists neither a torch, a feeder nor cables, so before you buy ask about the equipment and about which interface this unit supports. Without a matching Push-Pull torch you are left with standard feeding.
For aluminium you need U groove rolls, a teflon liner in the torch and argon, and you route the cable assembly without sharp bends. The card gives neither weight nor dimensions, ask before transport.
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.
