Understand the difference.

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

CT

Symbols

Current transformer

A current transformer produces a secondary current related to the current in its primary conductor. A drawing uses the CT representation to show where current is measured and which metering or protection circuit receives that measurement. It does not, by itself, specify the CT ratio, accuracy class, burden or secondary connection.

Drawing use

SLD / Schematic

Application

Metering & protection

Reference family

IEC / IEEE / ANSI

A distinction that matters

A CT measures current. A VT measures voltage. Their secondary circuits and isolation/testing arrangements are different.

Full referenceAdd to legend

VT / PT

Symbols

Voltage transformer

A voltage transformer provides a secondary voltage related to the voltage on its primary winding. VT and PT, for potential transformer, are common terms encountered in power drawings. Its representation identifies a measurement function; winding connections, fuses, earthing and secondary circuits need their own documented detail.

Drawing use

SLD / Schematic

Application

Metering & protection

Reference family

IEC / IEEE / ANSI

A distinction that matters

A VT supplies a voltage measurement; a power transformer supplies a power circuit. A shared transformer-like outline does not make their functions interchangeable.

Full referenceAdd to legend

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.