Transformers

10 kV, 11 kV and 13.8 kV transformers differ in ratio, insulation level and tap range. Here is how to pick the right voltage class and avoid a costly mismatch.

How percentage impedance sets the fault level, the voltage drop and the parallel operating rules, with worked fault-current and regulation calculations.

How to read transformer model numbers such as SCB13, SGB10, S11-M and S20: every letter and number explained, plus the eight ratings the code does not cover.

Transformer ODM and OEM programs explained: the custom engineering workflow from RFQ to FAT, the 15-field spec sheet, tooling and IP ownership, MOQ and lead-time terms.

SCB10, SCB13, SCB14 and SCB18 compared on loss values, efficiency grade, price and lifetime payback, with a worked capitalised-loss example at 1000 kVA.

What an efficiency class regulates, how EU ErP, DOE and GB 20052 differ, why load points are not comparable, and how to capitalise losses into a 25-year cost.

How to read the IEC cooling code on a transformer nameplate, what each class adds in capacity, and what it costs in noise, auxiliary power and maintenance.

DETC or OLTC? A practical comparison of off-circuit and on-load tap changers for medium voltage transformers, covering range, step size, cost, maintenance and specification.

In 2026 large power transformers average about 128 weeks while distribution units run 12-30 months. Here is what MOQ, lead time, payment terms and Incoterms really look like for buyers.