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

Blocking or out-of-step supervision

Restrains or coordinates another protection action under the specified system condition.

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

A distinction that matters

Manufacturers also map inrush detection or selectivity logic to 68; the number alone does not identify a universal power-swing algorithm.

Full reference

Protection functions

Differential protection

Differential protection compares quantities associated with the boundaries of a protection zone according to the selected implementation. Equipment and application suffixes can distinguish transformer, busbar, line or other arrangements. The base number alone does not define the zone or measurements.

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

A distinction that matters

Transformer differential, busbar differential and other differential applications are not interchangeable merely because they share the base number 87.

Full reference

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