Transformers

A practical guide to grounding the secondary of small dry-type step-up and step-down transformers — which conductor to bond, how to verify it, and mistakes to avoid.

A practical guide to transformer turns ratio testing on low voltage units - the applied-voltage method with a variac, tolerance limits, tap checks, and when to call for a ratio tester.

A practical guide to measuring the DC resistance of transformer windings and motor coils, covering four-wire setup, test current selection, temperature correction and pass/fail limits.

A control transformer steps a 380 V or 480 V supply down to the 120 V or 24 V that relays, contactor coils and PLC inputs run on. Learn how it works, why inrush VA — not sealed VA — sets the rating, and how to size, tap, fuse and ground one.

A practical guide to transformer live and neutral wiring: how to identify L and N terminals, connect them correctly, and avoid the hidden shock hazards of a reversed input.

Learn how to convert single phase to three phase power with VFDs, rotary and static phase converters, plus sizing rules and where transformers fit.

Compare single-phase and three-phase transformers on windings, capacity, voltage stability, efficiency, and cost — then pick the right one for your load and supply.

A three-phase transformer can supply single-phase loads — but only with the right winding tap and the right derating. Here's the wiring, the math and the limits.

What is transformer no-load loss? A clear breakdown of hysteresis and eddy current loss, the calculation formulas, the open-circuit test method, and how a lower-loss core pays back over the service life.