Understand the difference.

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

SS

IEC

IEC selector-switch contact: normally open delayed contact

A rotary selector has discrete handle positions and one or more contact blocks driven by its mechanism. A contact shown as normally open or normally closed describes the stated reference position; it does not give the whole switching table across the remaining positions. This entry identifies the normally open delayed contact form in the publisher's IEC-context family.

Drawing use

Schematic

Application

Control circuits

Reference family

IEC / Manufacturer

Form evidence

Normally Open Delayed Contact. Autodesk IEC-60617 Symbol Preview: Selector Switches, HSS218F / VSS218F. This identifies the publisher's library context; exact IEC graphics and database identities are not asserted.

A distinction that matters

This entry adds the normally open delayed contact detail to the broader selector-switch contact family. A vendor neutral-position number must be read with that vendor form and the project legend. It does not automatically establish a key-removal position, a contact overlap or an off state. Those details need their own table or equipment reference.

Full referenceAdd to legend

SS

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 referenceAdd to legend

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