Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

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TNMI

Symbols

Transformer neutral-current measurement interface

Identifies the separately measured transformer neutral-current signal serving the assigned protection input. Transformer monitoring interfaces connect physical sensors and protection calculations to the station's alarms and trip logic. Temperature, oil, gas, pressure and electrical measurements indicate different conditions and require separate interpretation.

Drawing use: Schematic
Application: Metering & protection
Reference family: Manufacturer

A distinction that matters

A measured neutral input differs from calculated residual current. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Full reference

Symbols

Power transformer

A power-transformer representation identifies equipment transferring electrical power between winding circuits. The generic mark can show the relationship between windings, but voltage levels, winding connections, vector group, rating and earthing information require additional annotations and equipment references.

Drawing use: SLD / Schematic
Application: Power distribution
Reference family: IEC / IEEE / ANSI

A distinction that matters

A transformer used for voltage measurement is a VT or PT. Its function and secondary circuit differ from those of a power transformer.

Full reference

Follow the full entry for source drawings and the appropriate standard or selected product. Equipment previews show a manufacturer drawing where available, otherwise a 3D thumbnail.