NC UNLATCH
Manually unlatched NC contact
A manually unlatched NC contact has a mechanical retained state and a documented manual release.
Schematic
IEEE / ANSI · NC UNLATCH
ANSI/IEEE Manually unlatched NC contact form
IEEE-library form of manually unlatched nc contact: a manually unlatched NC contact has a mechanical retained state and a documented manual release.
In plain English
What does ANSI/IEEE Manually unlatched NC contact form mean?
This reference locates manually unlatched nc contact in Autodesk's IEEE-oriented relays and contacts family. A manually unlatched normally closed contact has a mechanical retained state and a documented manual release. Its reference state is closed but the retained operated position must be stated. The public library uses HCR2221F for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
A simple example
Trace the measured quantity or initiating control signal separately from the output contacts. The device tag links the sensing or operating element to the controlled circuit; settings, reset behaviour and the actual terminal arrangement belong in the selected equipment documentation.
What the drawings help you do
Confirm which contact position the mechanism retains. A mechanical retention marker must not be confused with a delayed-return timer marker. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.
This particular reference
IEEE-library form of manually unlatched nc contact: a manually unlatched normally closed contact has a mechanical retained state and a documented manual release. A mechanical retention marker must not be confused with a delayed-return timer marker.
- Normally open / normally closed
- The contact state in the normal condition defined for the drawing.
- Coil
- A wound conductor that can produce a magnetic field when energised.
- Terminal
- An identified point where a conductor connects.
Read the source: Autodesk IEEE Symbol Preview — Relays and Contacts
IEEE / ANSI · With Mechanical Block and Manual Unlatching
Autodesk IEEE Symbol Preview: Relays and Contacts, block HCR2221F. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
Schematic · NC UNLATCH
What it represents
This reference locates manually unlatched nc contact in Autodesk's IEEE-oriented relays and contacts family. A manually unlatched NC contact has a mechanical retained state and a documented manual release. Its reference state is closed but the retained operated position must be stated. The public library uses HCR2221F for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
Trace the measured quantity or initiating control signal separately from the output contacts. The device tag links the sensing or operating element to the controlled circuit; settings, reset behaviour and the actual terminal arrangement belong in the selected equipment documentation.
Confirm which contact position the mechanism retains. A mechanical retention marker must not be confused with a delayed-return timer marker. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.
How to read it
- Confirm which contact position the mechanism retains.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.
Information to show or reference
- State reference and retained states
- Identify manual release
- Link associated device
A distinction that matters
A mechanical retention marker must not be confused with a delayed-return timer marker.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Autodesk IEEE Symbol Preview — Relays and Contacts
Public IEEE-oriented Relays and Contacts table explicitly lists HCR2221F as With Mechanical Block and Manual Unlatching. This supports the vendor convention context, not reproduction of the publisher graphic.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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