Understand the difference.

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

PB NO

IEEE / ANSI

ANSI/IEEE normally open pushbutton symbol

The momentary NO pushbutton form associates an operator action with an initially open contact. Read the actuator and contact together, then identify the control path that becomes continuous while the button is operated.

Drawing use

Schematic

Application

Control circuits

Reference family

IEEE / ANSI / Manufacturer

Form evidence

Autodesk IEEE-oriented Push Buttons 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 momentary pushbutton returns mechanically; a latched pushbutton retains its position.

Full referenceAdd to legend

PB NO

Symbols

Normally open pushbutton

A normally open pushbutton combines an operator-actuated mechanism with a contact shown open in its defined normal state. Momentary and maintained or latching operation are separate characteristics that must be described explicitly.

Drawing use

Schematic

Application

Control circuits

Reference family

IEC / IEEE / ANSI

A distinction that matters

A NO contact symbol by itself does not identify the pushbutton actuator or its mechanical operating mode.

Full referenceAdd to legend

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