ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Difference between fuses and circuit breakers.

Updated on August 8, 2017
goodnews11 profile image

Electrical and Automation Engineer . Specialized in LV Switchgear Design and process automation

Copyright © 2014 goodnews11. All Rights Reserved

Circuit breakers and fuses, in spite of performing a common task of interruption of the flow of fault current to an equipment or system, are entirely different from each other in all aspects of construction and principle of operation. Whenever a short circuit or an overload occurs, heavy fault current flows through the equipment that may damage the equipment and may cause interruption of service. Here arises the need for the protection devices such as fuses, relays, circuit breakers etc. The main function of these devices is to interrupt the flow of fault current to an equipment and protecting it from severe damage. Few people think that the circuit breakers and the fuses are the same. But it is not. This article will make you clear “what is a circuit breaker?” “What is an electric fuse?” and the difference between them.

Circuit Breaker

Circuit breaker

A circuit breaker is a mechanical device used to perform switching operations in an electrical circuit under normal as well as abnormal conditions. When a circuit breaker is employed in the protection of an electrical circuit, they are equipped with a trip coil connected to a relay arrangement, which is designed to sense the abnormal conditions and close the breaker trip circuit. Therefore an additional relay arrangement is always required for the automated operation of a circuit breaker. For breakers of very small capacity, for example, low voltage circuit breakers up to 100A, have thermal couple arrangement instead of fault sensing relays.

Operating principle of Circuit breakers

The simplified operating principle of a circuit breaker is as follows: A circuit breaker consists of a fixed contact and a moving contact. Under normal conditions, these contacts will be closed allowing current to flow through it. When an abnormal condition is sensed by the relay arrangement provided, it energizes the trip coils and pulls back the moving contact apart and opens the circuit breaker, thereby interrupting the flow of current. The circuit breaker is reset manually or automatically after the clearance of fault. Circuit breakers can also be operated manually.

A model of circuit breaker relay arrangement

Buy RCCB for your home and shield yourself from electric shocks

Fuses

Fuse

Fuse is also a protection device that is entirely different in construction as well as in operation from the circuit breakers. A fuse consists of a fusing element held between two metal contacts. It is connected in before and in series to the equipment or the circuit to be protected. It is the simplest and the cheapest protection device and does not require any additional relay arrangements.

Operating principle of fuses

An electric fuse works on the principle of heating effect of the electric current. When the current flowing through the fuse element is within the limits, the heat developed on the fuse element will be completely dissipated to the surrounding air. During the occurrence of fault, the current flowing through the fuse element increases rapidly and the heat generated cannot be dissipated so fast and thus the fuse element melts and breaks the circuit. Fuse once blown out cannot be reused. Rewirable fuse can be reused after replacing the blown out fuse element with a new one.

Difference between fuse and circuit breakers

Difference between fuse and circuit breskers
Difference between fuse and circuit breskers

Comparison between fuse and circuit breakers

S. No.
Particulars
Fuse
Circuit breakers
1
Function
Fuse is used for the detection of fault as well as the interruption of circuit.
Circuit breakers perform switching operations (make and break operations) alone. Fault detection is made by protective relays.
2
Principle of operation
The operation of electric fuses is based on the heating property of electric current.
Operation is based on common switching principle.
3
Mode of operation
Completely automatic
Manual operation. To make circuit breakers automatic, additional relay arrangements should be made.
4
Additional equipments required
No additional equipments are needed.
For automated operations additional relay arrangements should be needed.
5
Operating time
Operating time of fuses is very small, close to 0.002 seconds.
Operating time of circuit breakers are more than that of the fuses. ( 0.02 -0.05 seconds)
6
Breaking capacity
Breaking capacity of fuses is small.
Breaking capacity of circuit breaker is large.
7
Reusability
All other types of fuses except rewirable fuses are non reusable. Rewirable fuse can be reused after replacing the burnt out fuse element with a new one.
Circuit breakers can be reused.
8
Cost
Less
Very high compared to that of the fuse.

Where to be used?

Fuses can be used in the protection of low voltage circuits. For the protection of high voltage circuits, say 33kV and above, Circuit breakers are employed. Circuit breakers are mostly preferred where the chances for the occurrence of fault are more. Fuses are commonly employed in the protection of cables in low voltage lights, power circuits, in transformers having rating not more than 200kVA and in small electronic circuits.

Test your knowledge!

view quiz statistics

Comments

    0 of 8192 characters used
    Post Comment

    • Spree profile image

      Spree 

      6 weeks ago

      Accurate informative and to the point

    • goodnews11 profile imageAUTHOR

      OSBERT JOEL C 

      3 years ago from CHENNAI

      Thank you Jane Ramona Rynkiewicz Frieman..

    • J - R - Fr13m9n profile image

      Jane Ramona Rynkiewicz Frieman 

      3 years ago from Morris County, New Jersey

      This is a well written and informative article about fuses and circuit breakers. My brain is "wired" for creativity though.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)