# IEC inductive proximity sensor: normally closed 3 wire

Canonical URL: https://eloragrid.ai/symbols/iec-inductive-proximity-sensor-normally-closed-3-wire
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: IND
Drawing use: Schematic
Reference families: IEC, Manufacturer

## Symbol convention

Convention: IEC
Form: Normally Closed 3 Wire
Autodesk IEC-60617 Symbol Preview: Inductive Switches, HPX12IN3 / VPX12IN3. This identifies the publisher's library context; exact IEC graphics and database identities are not asserted.

Inductive proximity sensor form: Normally Closed 3 Wire.

## In plain English

### What does IEC inductive proximity sensor: normally closed 3 wire mean?

An inductive proximity sensor detects a metallic target through the effect it has on an electromagnetic sensing field. This entry identifies the normally closed 3 wire form in the publisher's IEC-context family.

### A simple example

A metal flag on a carriage can produce a controller input without touching a mechanical switch. The normally-closed designation starts with a conducting output or closed contact in the documented reference condition; operation changes that state. The three-wire form distinguishes supply, return and switching output. Confirm sourcing or sinking operation from the actual sensor circuit before connecting it to an input.

### What the drawings help you do

Target material, sensing distance and output circuit are product properties; an inductive mark does not identify PNP, NPN or a universal terminal assignment.

### This particular reference

Inductive proximity sensor form: Normally Closed 3 Wire. This entry adds the normally closed 3 wire detail to the broader inductive proximity sensor family. Target material, sensing distance and output circuit are product properties; an inductive mark does not identify PNP, NPN or a universal terminal assignment.

### Terms

- Normally open / normally closed: The contact state in the normal condition defined for the drawing.
- Terminal: An identified point where a conductor connects.
- Signal: Electrical information passed between devices, rather than necessarily the main power supply.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [AutoCAD Electrical: Inductive proximity switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-596652AB-6555-4F9A-B575-555D40C2ECD4.htm)


## What it represents

An inductive proximity sensor detects a metallic target through the effect it has on an electromagnetic sensing field. This entry identifies the normally closed 3 wire form in the publisher's IEC-context family.
A metal flag on a carriage can produce a controller input without touching a mechanical switch. The normally-closed designation starts with a conducting output or closed contact in the documented reference condition; operation changes that state. The three-wire form distinguishes supply, return and switching output. Confirm sourcing or sinking operation from the actual sensor circuit before connecting it to an input.
Target material, sensing distance and output circuit are product properties; an inductive mark does not identify PNP, NPN or a universal terminal assignment.

## How to read it

- The normally-closed designation starts with a conducting output or closed contact in the documented reference condition; operation changes that state.
- The three-wire form distinguishes supply, return and switching output. Confirm sourcing or sinking operation from the actual sensor circuit before connecting it to an input.
- Target material, sensing distance and output circuit are product properties; an inductive mark does not identify PNP, NPN or a universal terminal assignment.

## Information to show or reference

- Identify the target, sensing mode and expected normal condition.
- Label supply, output and connector pins from the actual device diagram.
- Reference output circuit type, operating range and controller input.

## Important distinction

This entry adds the normally closed 3 wire detail to the broader inductive proximity sensor family. Target material, sensing distance and output circuit are product properties; an inductive mark does not identify PNP, NPN or a universal terminal assignment.

## Facts

- Drawing form: Normally Closed 3 Wire
- Public vendor block names: HPX12IN3 / VPX12IN3. Autodesk identifiers, not standards database IDs.
- Drawing purpose: inductive proximity sensor
- Graphic scope: Independently authored educational illustration; not certified standard geometry, a terminal pinout or a product footprint.

## Public references

- [AutoCAD Electrical: Inductive proximity switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-596652AB-6555-4F9A-B575-555D40C2ECD4.htm) — Autodesk. Public Inductive Switches table explicitly lists HPX12IN3 / VPX12IN3 with this operating or connection form. Vendor graphics are linked, not copied.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.