Inside a Box-Type Transformer
Box-type transformers —also known as pad-mounted or compact substations—encapsulate all major transformer and switchgear components within a single, weather-proof enclosure. These units integrate high-voltage (HV) switchgear, the transformer core and windings, low-voltage (LV) distribution gear, protection devices, cooling systems, and monitoring instruments into one compact assembly. Their design maximizes safety, space efficiency, and ease of installation for urban and suburban power distribution networks. Transformer Core and Windings At the heart of every box-type transformer lies the magnetic core, typically constructed from laminated silicon-steel sheets to minimize eddy-current losses and provide a low-reluctance path for magnetic flux. Wrapped around the core are two sets of windings—primary (HV) and secondary (LV)—made of enamelled copper or aluminium conductors. These windings are insulated from each other and the core using high-grade insulating paper and pressboard to withs...