Customers currently in the duration of their trial period will not be able to download model data.
Please provide the application note numbers that you wish to review for your distributor support team.
Please be aware that services differ from the free-to-register “JMAG-Express Online” and the “JMAG Technical Library”.
Vacuum circuit breakers have the function of breaking the current when a large current flows due to a short circuit or other reason in distribution boards, etc. Contact pressure is applied to the contacts in a vacuum circuit breaker because it is necessary for the vacuum circuit breaker’s contacts to be in contact and the electric circuit to be closed when normal current is flowing, unlike the large current from a short circuit.
Electromagnetic repulsion is produced by the current flowing in a vacuum circuit breaker’s contacts when current flows through the vacuum circuit breaker. Therefore, it is necessary to evaluate the electromagnetic repulsion and set the contact pressure higher than the electromagnetic repulsion in order to maintain a closed state during normal current.
This Application Note presents how to obtain the electromagnetic repulsion in a circuit breaker from the Lorentz force when a 100 kA current is flowing.
Current Density Distribution
Current density distributions are shown in figures 1, 2, and 3. The current that flows into the supporting conductor of the lower electrode divides in the coil and flows to the contact via the contact points as shown in (a). Then, the current that has flowed into the contact is concentrated at the contact point as seen in (b). When current flows into the contact of the upper electrode from the narrow contact points, it tries to spread out as shown in fig. 3.
Lorentz Force Density Distribution and Electromagnetic Force
The Lorentz force density distribution is shown in fig. 4. Vertically repulsive force is generated in the contacts by the current flowing as shown in fig. 3.
Electromagnetic repulsion of approximately 700 N is generated in the contacts.
This website uses cookies to improve functionality and performance. If you continue browsing the site, you are giving implied consent to the use of cookies on this website.
If you want to know more or refuse consent, read our Cookie Policy. Accept
Cookies Policy
Privacy Overview
This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.