Definition

trip unit (circuit breaker)

Part of the Electronics glossary:

A trip unit is the part of a circuit breaker that opens the circuit in the event of a thermal overload, short circuit or ground fault.  An open circuit will not conduct electricity because either air, or some other insulator has stopped or broken the flow of current in the loop.

There are two types of trip units, electromechanical (also called thermal magnetic) and electronic.   An electromechanical trip unit has moving parts; it combines a current-sensitive electromechanical device with a thermal-sensitive device and the two devices work together to determine when to  mechanically open the circuit. An electronic trip unit is programmable device which measures and times current flowing through the circuit breaker and initiates a trip signal when appropriate.

This was last updated in June 2011
Posted by: Margaret Rouse

Related Terms

Definitions

  • frequency jammer

    - Frequency jamming is the disruption of radio signals through use of an over-powered signal in the same frequency range. When most people think of frequency jamming, what comes to mind are radio, r... (WhatIs.com)

  • anode

    - An anode is the electrode in a polarized electrical device through which current flows in from an outside circuit. Conversely, a cathode is the eletrode in a polarized electrical device through whi... (WhatIs.com)

  • cathode

    - A cathode is the metallic electrode through which current flows out in a polarized electrical device. Conversely, an anode is the electrode in a polarized electrical device through which current fl... (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About trip unit (circuit breaker)Powered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.