Get the FULL video transcript here: https://www.rspsupply.com/education/a-23-what-is-a-circuit-breaker/ Want to see similar products to those featured in this video: https://www.rspsupply.com/c-670-breakers-fuses.aspx Check out our full line of Industrial Hardware on our website: https://www.rspsupply.com/ The circuit breaker is an absolutely essential device in the modern world, and one of the most important safety mechanisms in your home. Whenever electrical wiring in a building has too much current flowing through it, these simple machines cut the power until somebody can fix the problem. Without circuit breakers (or the alternative, fuses), household electricity would be impractical because of the potential for fires and other mayhem resulting from simple wiring problems and equipment failures. In this article, we'll demonstrate how circuit breakers and fuses monitor electrical current and how they cut off the power when current levels get too high. As we'll see, the circuit breaker is an incredibly simple solution to a potentially deadly problem. The simplest circuit protection device is the fuse. A fuse is just a thin wire, enclosed in a casing, that plugs into the circuit. When a circuit is closed, all charge flows through the fuse wire -- the fuse experiences the same current as any other point along the circuit. The fuse is designed to disintegrate when it heats up above a certain level -- if the current climbs too high, it burns up the wire. Destroying the fuse opens the circuit before the excess current can damage the building wiring. The problem with fuses is they only work once. Every time you blow a fuse, you have to replace it with a new one. A circuit breaker does the same thing as a fuse -- it opens a circuit as soon as current climbs to unsafe levels -- but you can use it over and over again. The basic circuit breaker consists of a simple switch, connected to either a bimetallic strip or an electromagnet. The diagram below shows a typical electromagnet design. The hot wire in the circuit connects to the two ends of the switch. When the switch is flipped to the on position, electricity can flow from the bottom terminal, through the electromagnet, up to the moving contact, across to the stationary contact and out to the upper terminal. The electricity magnetizes the electromagnet (See How Electromagnets Work to find out why). Increasing current boosts the electromagnet's magnetic force, and decreasing current lowers the magnetism. When the current jumps to unsafe levels, the electromagnet is strong enough to pull down a metal lever connected to the switch linkage. The entire linkage shifts, tilting the moving contact away from the stationary contact to break the circuit. The electricity shuts off. Circuits breakers are one of the most important electrical devices in the world today Whenever too much current is flowing through a device in our homes, places of work or industrial buildings these devices can cut power to avoid problems such as fire, electrocution. Without this protection it would be very difficult to prevent problems from consistently happening. In todays video we want to talk about how circuit breakers can monitor electrical current and how the can disconnect power when the current gets too high. Fuse verses breakers Fuses provide the same kind of protection, but in a different way. When too much current flows through the fuse, they are designed to blow in order to interrupt electrical flow Problem – you can only use them once, and then they must be replaced Breakers can be used over and over while provided the same type of protection that a fuse will They consist of a switch connected to a bimetal strip or an electro magnet Two different types of technology commonly seen in breakers, Magnetic and thermal protection. Both work well, but have specific functions they excel in How they work Magnetic Better for detecting and reacting to a short circuit. Extreme spikes is current or voltage. current passes through the electromagnet coils so the electromagnet pulling the contact open, thus disconnecting power Thermal Provides protection against prolonged overcurrent Uses a bimetal strip that will heat and bend and engage the trip bar which will disconnect power. Thermal-Magnetic Thermal-magnetic breakers are often employed where it is important to quickly limit short-circuit current Thermal-magnetic circuit breakers contain two different switching mechanisms, a bimetal switch and an electromagnet. The bimetal serves as a means of handling overcurrent’s Electrical current exceeding the breaker-overload rating heats the bimetal enough to bend it toward the trip bar.