Understand the difference.

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

OPSR

Symbols

Outdoor post-insulator support reference

Identifies a primary conductor's insulating support function in the assigned yard arrangement. High-voltage primary equipment carries, interrupts, measures or conditions the main power circuit. Its function, insulation arrangement and equipment boundaries need to be distinguished from the secondary signals used to control it.

Drawing use

Schematic

Application

Power distribution

Reference family

Manufacturer

A distinction that matters

A support does not create an electrical interruption. 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 referenceAdd to legend

TX

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 referenceAdd to legend

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.