The substation transformer is the heart of the electrical substation. In the United States, the features and functionality of most distribution transformers fall under IEEE standard C57.12.00 (Standard General Requirements for Liquid-Immersed Distribution Power and Regulating Transformers), however, there are a multitude of standards that apply to specific types and applications of transformers including substation type, compartmental padmount type, single-phase pole mounted transformers, generator duty transformers, high-temperature transformers, and many more. Modern distribution transformers are manufactured in accordance with many standards, most notably by IEEE (Institute of Electrical and Electronics Engineers) and IEC (International Electrotechnical Commission). Some distribution voltages may exceed 35 kV and would be considered high voltage, but most of the distribution system is within the medium-voltage range. Practical levels of voltage are often referred to as medium voltage, meaning the incoming voltage to the transformer is on the order of 5 kV to 35 kV. Server racks, enclosures & airflow managementĪ medium-voltage distribution transformer or service transformer is a transformer type that provides the final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the level used by the customer.Safety, security & emergency communications.Process safety, automation, test and measurement.Medium-voltage power distribution & control systems.Low-voltage power distribution & control systems.

Industrial controls, drives, automation and sensors.Backup power, UPS, surge & IT power distribution.

Power transformer wire color code