Understand the difference.

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

NC

IEEE / ANSI

ANSI/IEEE normally closed contact symbol

The normally-closed relay contact form identifies a conducting path in its documented unoperated condition. The operating action changes that path; it does not tell the reader whether the controlled equipment is normally running or stopped.

Drawing use

Schematic

Application

Control circuits

Reference family

IEEE / ANSI / Manufacturer

Form evidence

Autodesk IEEE-oriented Relays and Contacts functional form. Autodesk explicitly publishes this block under IEEE Symbol Preview. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.

A distinction that matters

A closed reference contact and a closed circuit breaker describe different devices and circuit duties.

Full referenceAdd to legend

NC

Symbols

Normally closed contact

A normally closed contact is closed in the normal state specified for its device. Actuating the parent device may open it. The drawing must establish that state convention and associate the contact with the appropriate equipment and terminal designations.

Drawing use

Schematic

Application

Control circuits

Reference family

IEC / IEEE / ANSI

A distinction that matters

An NC mark does not prove a circuit is fail-safe or establish positive-opening characteristics. Consult the selected device and complete control design.

Full referenceAdd to legend

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