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

NC HOLD

Symbols

Maintained normally-closed contact

A maintained NC contact retains its actuated position until the documented return action occurs. The unactuated closed state and retained operated state must both be understood.

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

A distinction that matters

A maintained contact is not necessarily an electrically latching relay.

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.