What Is on a Transformer Rating Plate?
Quick answer — A transformer rating plate (nameplate) gives the manufacturer, serial, the rated kVA/MVA, both voltage classes and the voltage ratio, the frequency, the impedance, the cooling class, the vector group, the losses, the insulation class, the temperature rise, and the connection/diagram. It is the authoritative summary of the design and is essential for operation, parallel and maintenance.
What does a transformer nameplate / rating plate show?
Electrical ratings
Rated MVA/kVA, voltage ratio and both voltage classes, frequency, impedance (%Z), the no-load and load losses, and the vector group.
Design and duty
The cooling class (ONAN/ONAF/OFAF), the temperature rise, the insulation class, and the oil specification.
Identification and connection
Manufacturer, serial and type, the year and standard, the connection (vector) diagram, and the tapping range and positions.
References & standards
- IEC 60076-1
- IEEE C57.12.00
Related
Related manufacturers
Prolec GE (GE Vernova) · Prolec GE Waukesha · Hitachi Energy USA · Siemens Energy · Eaton · Virginia Transformer Corp
Related components
Technical content is prepared from engineering references, standards frameworks, manufacturer documentation and industry sources. Contractual or compliance decisions should refer to current official standards. TransformerPath Technical Editorial.
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