{"schemaVersion":1,"slug":"iec-selector-switch-contact-normally-open-anticipated-contact","name":"IEC selector-switch contact: normally open anticipated contact","kind":"symbol","abbreviation":"SS","aliases":["HSS217F","VSS217F","selector-switch contact Normally Open Anticipated Contact"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"Selector-switch contact form: Normally Open Anticipated Contact.","description":["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 anticipated contact form in the publisher's IEC-context family.","For a local/off/remote selector, prepare a contact-versus-position chart alongside the schematic. The chart tells the installer which input is active at each handle setting, while spring-return, maintained and key-operated marks explain how the operator reaches or leaves that setting. The normally-open designation starts with a non-conducting output or open contact in the documented reference condition; operation changes that state. The anticipated contact changes before the associated ordinary contacts during the stated mechanism movement; this is a relative sequencing indication, not a timer setting.","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."],"readingNotes":["The normally-open designation starts with a non-conducting output or open contact in the documented reference condition; operation changes that state.","The anticipated contact changes before the associated ordinary contacts during the stated mechanism movement; this is a relative sequencing indication, not a timer setting.","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."],"drawingChecklist":["Label every handle position and preserve its reference orientation.","Cross-reference a contact-versus-position chart.","State maintained positions, return directions and any key-removal conditions."],"distinction":"This entry adds the normally open anticipated 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.","facts":[{"label":"Drawing form","value":"Normally Open Anticipated Contact"},{"label":"Public vendor block names","value":"HSS217F / VSS217F. Autodesk identifiers, not standards database IDs."},{"label":"Drawing purpose","value":"selector-switch contact"},{"label":"Graphic scope","value":"Independently authored educational illustration; not certified standard geometry, a terminal pinout or a product footprint."}],"references":[{"sourceId":"autodesk-selectors","relevance":"Public Selector Switches table explicitly lists HSS217F / VSS217F with this operating or connection form. Vendor graphics are linked, not copied."}],"related":["selector-switch","three-position-maintained-selector","three-position-centre-return-selector"],"artwork":"s28-iec-selector-switch-contact-normally-open-anticipated-contact","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Normally Open Anticipated Contact","reference":"Autodesk IEC-60617 Symbol Preview: Selector Switches, HSS217F / VSS217F. This identifies the publisher's library context; exact IEC graphics and database identities are not asserted."},"plainEnglish":{"title":"What does IEC selector-switch contact: normally open anticipated contact mean?","introduction":"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 anticipated contact form in the publisher's IEC-context family.","example":"For a local/off/remote selector, prepare a contact-versus-position chart alongside the schematic. The chart tells the installer which input is active at each handle setting, while spring-return, maintained and key-operated marks explain how the operator reaches or leaves that setting. The normally-open designation starts with a non-conducting output or open contact in the documented reference condition; operation changes that state. The anticipated contact changes before the associated ordinary contacts during the stated mechanism movement; this is a relative sequencing indication, not a timer setting.","drawings":"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.","terms":[{"name":"Normally open / normally closed","meaning":"The contact state in the normal condition defined for the drawing."},{"name":"Signal","meaning":"Electrical information passed between devices, rather than necessarily the main power supply."},{"name":"Rating","meaning":"A value stating the conditions for which equipment is specified."}],"diagram":"flow","steps":["Identify the device and form","Read the connections and state","Check the equipment reference"],"caption":"A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.","sources":[{"label":"Selector-switch contact and operating variants","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-E1B4D1DE-C709-4E3E-AF7C-1A8989D096E9.htm"}],"detail":"Selector-switch contact form: Normally Open Anticipated Contact. This entry adds the normally open anticipated 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.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-selector-switch-contact-normally-open-anticipated-contact","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-selector-switch-contact-normally-open-anticipated-contact.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"autodesk-selectors","title":"Selector-switch contact and operating variants","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-E1B4D1DE-C709-4E3E-AF7C-1A8989D096E9.htm","type":"cad-reference","scope":"Maintained and returning selector-switch positions and associated contacts.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public Selector Switches table explicitly lists HSS217F / VSS217F with this operating or connection form. Vendor graphics are linked, not copied."}]}