# Thermal circuit breaker

Canonical URL: https://eloragrid.ai/symbols/thermal-circuit-breaker
Publisher: Elora Grid
Updated: 2026-10-13
Lookup label: CB TH
Drawing use: SLD, Schematic
Reference families: IEC, Manufacturer

A thermal circuit breaker uses a temperature-responsive trip mechanism to detect sustained overload.

## What it represents

A thermal circuit breaker uses a temperature-responsive trip mechanism to detect sustained overload. Thermal operation and short-circuit interruption capability are separate aspects of the selected device.

## How to read it

- Look for the overload characteristic and ambient-temperature conditions in the equipment schedule.
- 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

- Identify thermal setting
- Document breaking capacity
- Reference supply conditions

## Important distinction

Thermal tripping does not imply the same instantaneous response as magnetic tripping.

## Facts

- Drawing role: Circuit interruption
- Representation scope: Functional concept; not an official standard graphic or a product footprint
- Public vendor block reference: HCB11TH, VCB11TH (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

- [Circuit-breaker symbol variants](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-DB1548A3-A4D3-47E5-86AC-37000DC57D80.htm) — Autodesk. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.
- [Fundamental characteristics of a circuit-breaker](https://www.electrical-installation.org/enwiki/Fundamental_characteristics_of_a_circuit-breaker) — Schneider Electric — Electrical Installation Guide. 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.