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Transformer Nameplate Rating:

Transformer Nameplate Rating Details – The voltage ratio is specified as V1 (rated)/V2 (rated). It means that when voltage V1 (rated) is applied to the primary, the secondary voltage on full load at specified pf is V2 (rated).

The ratio V1 (rated)/V2 (rated) is not exactly equal to N1/N2, because of voltage drops in the primary and secondary. These drops being small are neglected and it is assumed that for all practical purposes

Transformer Nameplate Rating Details

The rating of the transformer is specified in units of VA/kVA/MVA depending upon its size.

Transformer Nameplate Rating Details

where V and I are referred to one particular side. The effect of the excitation current is of course ignored.

The Transformer Nameplate Rating also specifies the equivalent impedance, but not in actual ohm. It is expressed as the percentage voltage drop expressed as

Transformer Nameplate Rating Details

where all quantities must be referred to any one side.