Understand the difference.

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

BUTM

Symbols

Breaker-failure upstream trip matrix

Maps a confirmed breaker-failure condition to the breakers required to clear the defined zone. A protection scheme combines measurements, decision elements and communication or trip outputs to protect a defined part of the network. A function number names a job; the scheme interface shows how that job connects to other equipment.

Drawing use

Schematic

Application

Metering & protection

Reference family

Manufacturer

A distinction that matters

Destinations depend on the bus configuration. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Full referenceAdd to legend

BDCI

Symbols

Bus differential check-zone interface

Provides the separately defined overall check-zone condition used by a bus protection scheme. A protection scheme combines measurements, decision elements and communication or trip outputs to protect a defined part of the network. A function number names a job; the scheme interface shows how that job connects to other equipment.

Drawing use

Schematic

Application

Metering & protection

Reference family

Manufacturer

A distinction that matters

Check zones and discriminating zones have different roles. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Full referenceAdd to legend

Follow the full entry for source drawings and the appropriate standard or selected product. Equipment previews show a manufacturer drawing where available, otherwise a 3D thumbnail.