What are shielded distribution transformers and where are they used?

Delta Transformers shielded distribution transformers provide a copper electrostatic shield between the primary and secondary windings. The shield is grounded and thus shunts most noise and transients to the ground path rather than passing them through to the secondary. Shielded transformers are ideal for commercial or electrical installations where electronic circuitry operating at low voltage DC is present and is very sensitive to 'noise'.