Local Overheating Can Short Adjacent Transformer Windings

What the evidence preview establishes

Adjacent primary wires shorted in the first winding layer above the core after localized heating softened or decomposed their insulation. The resulting overcurrent fused wires together and open, producing extensive secondary thermal damage.

Why this case matters

For a burned transformer, dissect inward to preserve the earliest thermal evidence. Fused adjacent wires in the first winding layer, crossed turns, and construction differences can distinguish a local winding short from a winding-to-core event.