Inverter technology has largely superseded transformer technology for MIG and MMA (stick) welding, thanks to the improvements in controllability of the arc and the greater power density (more current output per kilogram of welding machine). Today’s state-of-the-art portable single-phase, multi-voltage, multi-process welding machines are a good illustration of this, with ESAB’s Rebel EMP 215ic being one example.

This machine enhances usability by means of a colour TFT screen on the front panel to support set-ups. Moreover, equipping the machine with an integral display screen means that digital copies of the operating manual and spare parts list can be stored on and accessed directly from the machine itself.

A special sMIG (smart MIG) function enables users to begin MIG welding — with an extremely stable arc — simply by setting the metal thickness and wire diameter. Unlike some ‘intelligent’ MIG welding machines there is no need to enter information for the shielding gas mix. Inexperienced welders can easily produce good quality welds, while skilled welders benefit from higher quality welds and faster setups.

Lightweight and compact, yet powerful and robust, the machine can weld dual shielded flux-cored wire up to 1.2 mm, which makes it very versatile for applications as diverse as small fabrication shops, construction sites and shipyards, particularly where it makes sense to run short welds with a portable machine and finish the length of the weld with a stationary unit.

Multi-tasking 

Another advantage of the inverter technology and onboard software is that the machine is capable of being used for MIG, flux-cored, MMA and Lift TIG welding – so customers no longer have to purchase multiple machines. Customers also find that the new machine can do more than might be expected from a single-phase unit. When operating from a 230V supply, the Rebel provides a MIG output of 20 to 220 amps, a stick output of 30 to 160 amps and a TIG output of 5 to 240 amps; when connected to 120V, the unit provides a MIG output of 15 to 130 amps, a stick output of 5 to 110 amps and a TIG output of 5 to 140 amps. 

Nevertheless, next-generation welding is not the sole preserve of single-phase machines. For instance, ESAB recently launched its inverter-based Renegade ES 300i MMA (SMAW)/LiveTIG (GTAW) welder that offers extreme power in a compact format: it weighs 15kg, measures 460 x 200 x 320mm and produces a maximum output of 300 amps at 40% duty cycle. Suitable for applications such as heavy fabrication, ship and offshore yards, construction, pipelines, and repair and maintenance, this machine is powerful enough to handle welding cables and work leads up to 100m long. Additional versatility is provided by the automatic voltage detection that accepts three-phase primary power ranging from 230V to 480V ±10%.

To maximise productivity and quality, performance features include Adjustable Hot Start, a process that provides optimal energy during the starting sequence, improves strike performance and reduces sticking. In addition, the Adjustable Arc Force function enables the operator to adjust the arc characteristics to find the right balance between arc control, penetration and weld bead appearance. Preferences can be stored in one of three memory functions. State-of-the-art weld control delivers a more stable arc, less spatter and improved arc starts and stops. Of course, improved weld quality results in less post-weld grinding and cleaning, as well as less rework, all of which helps to boost productivity.