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

DDII

Symbols

Dual DC-feed isolation interface

Shows the isolation boundaries between two separately identified control-power feeds. Control power supplies the command, protection and indication equipment associated with a switchgear assembly. The drawing must distinguish the source, each distribution branch and the functions lost if that branch fails.

Drawing use: Schematic
Application: Control circuits
Reference family: Manufacturer

A distinction that matters

Redundancy requires assessment of common components. 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 reference

Coil

Symbols

Relay coil

A relay coil represents an operating element that changes the state of associated contacts when the device operates. Coil and contact representations are often drawn in different locations to make the circuit easier to read. Their shared identifier and cross-references establish the relationship.

Drawing use: Schematic
Application: Control circuits
Reference family: IEC / IEEE / ANSI

A distinction that matters

A relay coil is not a contactor power pole. Similar operating-element marks can represent equipment with different switching duties.

Full reference

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.