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

Symbols

Selector switch

A selector switch provides a choice between operating positions such as local and remote or manual and automatic. Its contacts may be shown separately from the operator symbol. The contact truth table or switching schedule defines which contacts operate in each position.

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

A distinction that matters

A changeover contact describes connections; a selector switch also includes an operator and its position behaviour.

Full reference

Symbols

Changeover contact

A changeover contact connects a common terminal to one of two alternative contact paths according to its operating state. Form C and SPDT are terms commonly encountered for this arrangement. The actual terminal numbering and transfer behaviour come from the selected device.

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

A distinction that matters

Two unrelated NO/NC contacts are not automatically one changeover contact. Confirm whether they share a common connection and operating mechanism.

Full reference

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