Transformers

A transformer steps voltage up, steps it down, or isolates one side from the other. What decides whether it does that reliably for twenty years is the design work before it is wound, not the winding itself.

What separates a good unit from a cheap one is testing and insulation. A good transformer passes its megohm test and its insulation tests between primary, choke and secondary, and carries proper insulation between winding layers. Layer insulation is invisible once the unit is potted or tanked, which is exactly why it is the first thing a cheap build economises on.

We take the working environment, enclosure, use case and expected uptime as design inputs. The engineering team proposes a design, that design is reviewed against the specification before it is released to manufacture, and the finished unit goes through a full test workflow before it is signed off.

To quote, we need the purpose, the rating in kVA, primary and secondary voltage and frequency, and the environment — humidity, altitude, ambient temperature. We work back from your ambient and your load to calculate the worst-case rise before locking the temperature and insulation class, and we build across the full range of both.

Copper or aluminium is the real decision. Copper is the better conductor in every respect and it costs more, so it comes up on almost every quotation. Aluminium can produce an equivalent transformer, but only with a more detailed design and a harsher test regime — it is not a substitution, it is a different design problem. The thing buyers most often leave unspecified is the vector group and the primary taps.