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

87N

Protection functions

Neutral differential protection

Identifies a differential scheme involving neutral or residual-current quantities as defined by the equipment documentation.

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

A distinction that matters

The N suffix does not establish whether the scheme is high- or low-impedance restricted earth fault; record the actual scheme.

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.