Understand the difference.

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

TON NC

Symbols

On-delay normally-closed contact

An on-delay NC contact opens after the associated timing condition has persisted for its documented interval. Its unoperated closed state is read separately from the timing annotation.

Drawing use

Schematic

Application

Control circuits

Reference family

IEC / Manufacturer

A distinction that matters

An on-delay NC contact is not an off-delay NO contact even if a sequence produces similar output timing.

Full referenceAdd to legend

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 referenceAdd to legend

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