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

TOFF NC

Symbols

Off-delay normally-closed contact

An off-delay NC contact returns to its documented normally-closed state after the delay following removal of the timing trigger. Its role is read from the complete timer and contact circuit.

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

A distinction that matters

Contact polarity and timing direction are separate pieces of information.

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

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