Requirements for Pad-Mounted@ Compartmental-Type@ Self-Cooled@ Three-Phase Distribution Transformers@ 5 MVA and Smaller; High Voltage@ 34.5 kV Nominal System Voltage and Below; Low Voltage@ 15 kV Nominal System Voltage and Below
This standard covers certain electrical@ dimensional@ and mechanical characteristics and takes into consideration certain safety features of three-phase@ 60 Hz@ liquid-filled@ self-cooled@ pad-mounted@ compartmental-type distribution transformers. These transformers are rated 5 MVA and smaller@ with the high-voltage limit of 34.5 kV system nominal voltage and below@ and with the low-voltage limit of 15 kV system nominal voltage and below. These transformers are generally used for step-down purposes from an underground primary cable supply. This standard covers the connector@ bushing@ and terminal arrangements for radial- or loop-feed systems. Either certain minimum dimensions or certain specific dimensions shall be specified. This standard does not cover the electrical and mechanical requirements of any accessory devices that may be supplied with the transformer. Purpose This standard is intended for use as a basis for determining performance@ interchangeability@ and safety of the equipment covered and to assist in the proper selection of such equipment.