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

PMU

Symbols

Phasor measurement unit

A phasor measurement unit samples voltages and currents and calculates magnitude and phase angle referenced to an absolute time source, normally GPS. Data from many PMUs can then be compared to see angle differences across a network, oscillations and islanding.

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

A distinction that matters

A PMU reports time-aligned phasors; a phase-angle meter shows a local angle between two inputs.

Full reference

PHASE

Symbols

Phase-angle meter

A phase-angle meter indicates the phase relationship between documented signals. The schematic names the reference and compared input so the displayed angle is interpretable.

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

A distinction that matters

A phase-angle meter is not automatically a synchronism-check permissive relay.

Full reference

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