Transformers - Overhead-Type Distribution Transformers@ 500 kVA and Smaller: High Voltage@ 34 500 Volts and Below; Low Voltage@ 7970/13 800Y Volts and Below (Now Copyrighted by NEMA)
This standard is intended for use as a basis for determining the performance@ interchangeability@ and safety of the equipment covered@ and to assist in the proper selection of such equipment. This standard covers certain electrical@ dimensional@ and mechanical characteristics and takes into consideration certain safety features of single and three-phase@ 60-Hz@ mineral-oil-immersed@ selfcooled@ overhead-type distribution transformers 500 kVA and smaller@ with high voltages 34 500 volts and below and low voltages 7970/ 13 800Y volts and below. Such transformers may include one or more of the following features: (1) High-voltage@ overcurrent protection (2) High-voltage@ overvoltage protection (3) Low-voltage@ overcurrent protection (4) Low-voltage@ overvoltage protection NOTE: For polychlorinated-biphenyl (PCB) contamination in transformers@ refer to the latest federal regulations.