Before choosing a machine, it’s worth checking what your workshop’s consumer unit and incoming supply can actually handle, not just what socket is nearest the bench. Buying a three-phase-only machine for a single-phase workshop, or underestimating the load a higher-output single-phase welder places on existing wiring, are both avoidable problems with a bit of checking upfront.
Most domestic UK properties are supplied with single-phase power, typically 230V, which is more than adequate for light-duty inverter welders used for hobby work, repairs and general fabrication. Three-phase supply, commonly 400V to 415V across three live conductors, is standard in industrial premises and delivers power more efficiently to heavier equipment, which is why higher-output welders and plasma cutters, including some Fronius and ESAB machines, are often offered in a three-phase version.
Plasma cutting uses a jet of ionised gas, usually compressed air, forced through a nozzle at high speed and heated by an electric arc to a temperature hot enough to melt through electrically conductive metal. The molten material is then blown clear by the same jet, leaving a narrow, clean cut. Unlike oxy-fuel cutting, plasma works on any conductive metal, including stainless steel and aluminium, not just carbon steel. Hypertherm is the plasma cutting brand we get asked about most, and it’s worth understanding the basics before comparing specific units.
The practical difference comes down to what a machine can draw and sustain. A single-phase supply has a ceiling on how much continuous power it can deliver before tripping breakers or overloading domestic wiring, which is why the highest-output welding and cutting equipment is frequently three-phase only, or offers noticeably better duty cycle performance when run on three-phase. For workshops without an existing three-phase supply, bringing one in usually means an electrician and, in some cases, an application to the local distribution network operator.
A reliable, adequately sized compressed air supply is the part most first-time buyers underestimate. Undersized or contaminated air, whether from moisture, oil or an undersized compressor, is one of the most common causes of poor cut quality and shortened consumable life, so it’s worth checking a machine’s air requirements against what your compressor can actually deliver before you buy, not after.
Getting the right disc for the material and finish you’re after saves both abrasives and time, and it’s worth checking your current selection against the job list with a supplier who stocks a full abrasives range, such as Tec Products UK.
