Electrical circuits have devices to regulate the amount of current in the circuit, such as electrical fuses, circuit breakers, and surge protectors, to avert tragedies. Examples of these devices are seen above and detailed more below. The wires transporting current in and out of a structure are distinct and never come into direct contact. They do, however, reach all areas of the structure, so any contact between them will cause damage to both.
The two main methods for regulating current flow are with resistors and inductors. Resistors reduce current flow by dissipating energy in the form of heat, while inductors limit current flow by inducing a counter-electromotive force (EMF).
Resistors can be categorized as fixed or variable based on how much resistance they exhibit under normal operating conditions. Fixed resistors can only limit current flow, they cannot increase it. Variable resistors can increase or decrease their resistance depending on whether a voltage is applied to them or not. These resistors are usually used in power supplies to set the desired output voltage.
Inductors consist of a coil of wire surrounded by magnetic material. When current flows through the inductor, a magnetic field is created which causes a magnetic flux to run through the core of the inductor. This induces a voltage in the coil that opposes the direction of current flow.
Circuit protection devices, such as fuses and circuit breakers, are used to safeguard the wires and components of a circuit from overload. An overload occurs when too much current flows through a wire or component. The overload may cause overheating and eventual damage to the wire or component. Circuit protection devices prevent overloading by shutting off the power to the circuit. They also alert you to any problems in the circuit so you can take action before anything serious happens.
Overload protection comes in two forms: short-term and long-term. Short-term overload protection shuts off the power immediately after it has been activated. This prevents excess currents from flowing through the overloaded section of the circuit, thus preventing further damage. Long-term overload protection keeps the circuit shut off even after the overload condition has been corrected. This is useful for large circuits where several sections might be overloaded at different times during a power surge or fault.
Overloaded wiring present an electrical hazard because the extra current required to keep the circuit breaker open will eventually cause other parts of the wiring to heat up and fail. If not repaired, this problem could lead to an entire panel being out of service while the remaining parts of the circuit are replaced. The best solution is to ensure that your wiring is up to code and use protective devices where necessary.
Circuit protection devices prevent a harmful or excessive quantity of current or a short circuit in an electrical conductor automatically. These devices must be able to withstand high temperatures while maintaining their ability to break away from a circuit if needed. The three main types of circuit protection devices are fuses, breaker switches and ground fault interrupters (GFI). Fuses and breaker switches are available as single-pole, double-throw (SPDT) devices for making wiring changes easily. GFI's are tripped by any abnormal current flow in a wire, not just when there is a power failure. This type of device is required by law for all live wires that go into a home.
The main purposes of circuit protection devices are to protect people from being hurt by electricity and to prevent expensive damage to property and equipment. Without these devices, everyone would be killed or seriously injured by the high voltage inside power lines every time a heavy load is connected to them or a tree falls on a cable carrying electric service to your house. The same thing would happen if a large number of houses had hot water heaters or air conditioners running at the same time. The only way to stop this dangerous situation is with a circuit protector.
A fuse is an electrical device used in electrical circuits to safeguard the circuit against overcurrent. It is made out of a metal strip that liquefies when the current flowing through it is high. Circuits are built with a given voltage and resistance so that the current flow is predictable. If the current exceeds what the circuit was designed for, then the fuse will blow open.
Fuses come in many sizes and styles. The type you find in houses is called a "blown fuse". This means that the metal strip inside it has melted away, opening the circuit. You should never try to fix a blown fuse by applying pressure to it; this could cause other parts of the circuit to fail as well. A blown fuse is usually indicated by a loud buzzing or crackling noise when current passes through it and it melts away.
The term "circuit breaker" is also used to describe a fuse-like device that can be controlled from a wall switch. These units are designed to protect specific circuits within your house in the event of a power outage. They can be activated either manually by someone who knows how to operate it or automatically by a controller such as a solenoid. Circuit breakers are useful because they allow you to turn off the power to an entire section of a house without having to go room by room.
The last type of protection device is the anti-firewire cable.
Circuit protection is classified into two broad categories: 1 Fuselages 2 Circuit breakers (electromechanical). Each has advantages, which will be described further below. Fuses are classified into three types: fast-blow, slow-blow, and semiconductor. Each reacts differently to the fault current. The appropriate type should be selected based on how long you want the fuse to last before it needs to be replaced.
The fuselage of a circuit breaker or fuse is the shell that encloses the electrical components. They are usually made of metal or plastic. A circuit protector's fuse box or vault is where the fuses or fuse blocks are stored. On some older vehicles, the fuses were stored in the trunk or underneath the vehicle.
Today, there are two broad categories of circuit protectors: electromechanical and solid-state. Both have advantages and disadvantages, so which type should you use? That decision depends on your specific application needs and your budget.
Electromechanical circuit breakers use a magnetic field to automatically open the circuit when too much current flows through the line. These devices are effective at stopping short circuits because the current cannot pass through an open switch. However, they can't react quickly enough to prevent damage from persistent conductors. For this reason, electromechanical circuit breakers are not suitable for vehicles with live power sources such as engines or motors.