This standard covers certain electrical@ dimensional@ and mechanical characteristics and takes into consideration certain safety features of single-phase@ 60 Hz@ liquid immersed@ self-cooled@ submersible distribution transformers with separable insulated high voltage connectors. These transformers are rated 250 kVA and smaller@ with high voltages of 34 500GrdY/19 920 V and below and with low voltages of 600 V and below. These transformers are generally used for step-down purposes from an underground primary cable supply. These transformers are typically installed in an enclosure below ground level@ operated from above and suitable for continuous submerged operation. 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.