Understanding Duty Cycle Before You Buy An Inverter Welder

Duty cycle is one of the most misunderstood figures on a welder's spec sheet, yet it tells you more about real-world usability than the headline amperage does. It's expressed as a percentage over a ten-minute period at a given output, so a machine rated at 30% duty cycle at its maximum amperage can run for three minutes out of every ten at that setting before it needs to rest and cool.

The figure changes with output. Turn the amperage down and the duty cycle climbs, because the internal components are working less hard. This is why a welder can feel completely different in a busy production environment compared with occasional home workshop use: someone welding continuously through a shift needs a much higher duty cycle at their working amperage than someone doing short repair jobs a few times a week. It's the kind of spec worth comparing properly across brands such as Kemppi and EWM, not just reading off the headline amperage figure.

For anyone starting out, talking through process, budget and set-up with people who deal with first-time buyers regularly is generally worth more than another hour of reading spec sheets, and that's exactly the sort of conversation the advice line at www.tecproducts.co.uk is there for.

Budget for a first machine is rarely just the welder itself. A gas cylinder and regulator for MIG or TIG, a decent auto-darkening helmet, gloves and basic workshop ventilation all add to the real cost of getting started, and skimping on the supporting equipment tends to cost more in frustration than it saves in cash. It's worth pricing the whole set-up before settling on a machine at the top of the budget.

Our own TP Weld Tables range is designed and manufactured in-house in Yorkshire, cut on a fibre laser for tight tolerances, which is the kind of detail worth asking about wherever you're sourcing a table, and you can see the full range via www.tecproducts.co.uk.

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.