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.

First referenceCompare with

Protection functions

Field-changing contactor

Changes the machine excitation connection or arrangement as part of a controlled field sequence.

Drawing use: SLD / Schematic
Application: Metering & protection
Reference family: IEEE / ANSI

A distinction that matters

Field-changing 93 switches an excitation arrangement; field application 56 initiates application of the field.

Full reference

Protection functions

AC circuit breaker

Device function number 52 identifies an AC circuit breaker in the power-system device-function convention. It can appear in equipment identification, control references or a protection drawing, but it remains distinct from the graphical symbol and product specification.

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

A distinction that matters

The number 52 identifies a device function. It is not an IEC graphical-symbol identifier, breaker current rating or manufacturer model.

Full reference

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