# Relay coil with diode suppression

Canonical URL: https://eloragrid.ai/symbols/relay-coil-with-diode-suppression
Publisher: Elora Grid
Updated: 2026-10-13
Lookup label: K DIODE
Drawing use: Schematic
Reference families: IEC, Manufacturer

A relay with diode suppression includes a diode associated with its coil to limit the transient on de-energisation.

## What it represents

A relay with diode suppression includes a diode associated with its coil to limit the transient on de-energisation. The diode's documented connection makes control polarity important.

## How to read it

- Verify the coil and diode polarity using the chosen relay or socket diagram.
- 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

- Mark coil polarity
- Identify integrated suppression
- Reference release-time behaviour

## Important distinction

A suppression diode protects the control circuit; it is not a contact-side arc suppressor.

## Facts

- Drawing role: Relay operation
- Representation scope: Functional concept; not an official standard graphic or a product footprint
- Public vendor block reference: HCR1K33, VCR1K33 (Autodesk identifiers; not IEC symbol numbers)
- Identifier status: The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name.

## Public references

- [AutoCAD Electrical: Relay suppression components](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-AF7C83A4-33F4-4144-94BE-4C5F2F448FB8.htm) — Autodesk. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.
- [Relays and contacts: public symbol reference](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-011C62B8-9EC8-485C-B47D-B22A3F7B7574.htm) — Autodesk. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.

## 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.