An electric fuse is a device that blocks current flow in an electric circuit. A fuse is typically a small length of wire. The fuse is built of a substance with a high resistivity and a low melting point, so it melts when the wire overheats during high current flow. The heat also can melt other things, so care should be taken not to put other materials in line with the fuse. Fuse boxes contain several electric fuses. They can be located under a floor or roof panel, inside a wall, or outside on a pole.
Electric fuses are used in many household appliances and industrial processes that could cause damage if they remained energized for too long. Electric blankets and hair dryers have caused deaths due to these fuses blocking current while people are sleeping. Electric fences and alarm systems use electric fuses to prevent abnormal current flows that could destroy circuitry. The electrical system of a car includes electric fuses to protect against over-current conditions that could start a fire if gasoline spilled onto electrical wiring.
The term "fuse" may also be used as an adjective to describe items such as fuse boxes, which provide protection from excessive current with the aid of some type of heater element. These are usually found in power stations, substations, and large buildings where there is a risk of electricity leaking into surfaces that could lead to fire.
There are two types of electric fuses: magnetic and thermal.
An electric fuse is a safety device that limits the current flowing through an electric circuit. The purpose of a fuse is to protect the electric circuit and the electric equipment attached to it from harm. Fuses are used in electricity-consuming devices to prevent overloading or shorting of wires in those devices. A fuse is a mechanical switch designed to break under excessive current flow. The switch may be built into the fuse itself, as in the case of an integral fuse, or it may be a separate item connected by wire to the fuse. Most modern fuses are molded plastic, but some small gauge metal fuses also exist.
Fuses are available in many sizes and styles. They are usually labeled with both their ampere rating (such as "10 amp" or "20 amp") and with a designation of either "regular" or "extended". This indicates whether the fuse is intended for use on a circuit requiring less than 20 amps, or one that can handle up to 30 amps. Fuse boxes often contain several different size fuses to provide flexibility in protecting important parts of the circuit. For example, a household power distribution panel may contain not only large fuses but also smaller fusable links and even miniature fuses that can blow open inside circuit breakers.
An electric fuse is a safety device used to regulate current in an electric circuit that melts and breaks the circuit if there is an excessive flow of current through the circuit. The purpose of the fuse is to prevent electrical components from being destroyed by an overload or short circuit. Fuses can be either thermal or magnetic. Thermal fuses burn out when too much heat is built up inside the fuse housing, while magnetic fuses demagnetize when exposed to enough magnetic flux.
The electric fuse is connected in series with the load it is intended for. If the fuse blows, the circuit is open and no further current can pass through it. A new fuse should be installed in its place immediately after detecting the loss of the original fuse. Fuse boxes are available for rental by homeowners who wish to install electric fuses in their wiring system without assistance from a qualified electrician.
Thermal fuses are designed to break away at a specified temperature (usually about 220 degrees Celsius or 400 degrees Fahrenheit). This prevents any chance of damage occurring to other parts of the circuit if the person installing the fuse happens to touch the hot wire. Magnetic fuses contain a magnetic core around which two wires are wrapped. If these wires are exposed to a strong enough magnetic field, they will become magnetized and lose their resistance to electricity.
An electric fuse operates on the heating effect of an electric current. It is constructed of non-combustible thin metallic wire. A fuse is always linked in series with the circuit between the ends of the terminals. When there is no current flowing through the fuse, it does not heat up; when there is a short circuit or overload condition, the current flow through the fuse will be very high, which will cause the fuse wire to heat up rapidly and burn out.
The main purpose of an electric fuse is to prevent electrical equipment from being damaged by excessive current loads or short circuits. Fuses can also be used to protect people from getting hurt by an overloaded power supply. Electric fuses can be divided into two categories according to their construction: integral fuse and separate fuse. Integral fuses are parts of an assembly whose function is not limited to that of a fuse. Examples include strip fuses, slot fuses, and melt-down fuses. Separate fuses consist of one component designed specifically for use as a fuse. These include snap-, blow-, and tension-type fuses.
Electric fuses are commonly used in electricity distribution systems to protect other equipment from damage caused by overcurrents and short circuits. The two types of fuses most often found in home installations are ground-fault circuit interrupters (GFCIs) and appliance protective devices (APD's).
A fuse is a piece of wire with an extremely low melting point that serves as a safety device. When a strong current is passed across the circuit, it melts and breaks when the temperature rises above its melting point. It is used to prevent short circuiting and so safeguard electric appliances from harm. Fuses can be replaced by a circuit breaker but for some applications this is not an option.
The word "fuse" comes from the French word "feu," which means fire. The first electrical fuses were made in 1872 by English scientist Michael Faraday who invented the carbon arc lamp. He used silk thread for his fuse element. In 1913, the electric lightbulb changed all our lives and people began to worry about burning down their homes. Electric companies started manufacturing metal fuses because silk thread was not suitable for high currents. By the 1950s, almost all household electricity used metal fuses.
How do you know if your fuse is blown? If a fuse blows, there will be no continuity between its two terminals. So before you try to replace any fuse, first check that it isn't already blown. You may be able to tell from outside the case if it is blown, but often you need to open up the appliance in question to see if the fuse is damaged inside the case. If it is not blown, then you should replace it immediately before something burns out or sets off an alarm.