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

NO UNLATCH Manually unlatched NO contact: original educational illustration

Symbols

Manually unlatched NO contact

A manually unlatched NO contact includes a mechanical retaining action released by a documented manual operation. Its schematic modifier explains why removal of an initiating signal may not restore the initial state.

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

A distinction that matters

Manual unlatching concerns the mechanism, not the contact's load interrupting rating.

Full reference

Symbols

Normally open contact

A normally open contact is open in the normal state defined for the device. Operating its relay, pushbutton or other parent device may close the contact. The meaning of normal must be established from the drawing convention and equipment documentation; it is not necessarily the current live condition of the installation.

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

A distinction that matters

Normally open describes the stated normal condition. A position indication or operating snapshot may use a different state convention.

Full reference

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