Understand the difference.

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

DTSI

Symbols

Direct transfer-trip send interface

Transmits the local initiation assigned to a remote breaker opening function. 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

The destination and initiation scope must remain explicit. 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

WPSI

Symbols

Weak-infeed protection support interface

Identifies the documented support logic used where local fault contribution is limited. 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

The exact weak-infeed method is relay-specific. 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.