An electrical installation is a collection of components permanently connected to electricity, such as switchboards, lighting installation and socket outlets. An electrician must work to ensure all electrical standards and safety procedures are followed. Wiring safety codes vary by country or region. Most countries follow a model code produced by the International Electrotechnical Commission.
The first stage of an electrical installation involves gathering information from the client about what kind of work is required. It’s also important for your electrician to see a plan of the space where the electrical work will be done, so that they can plan what kind of materials and wiring is needed. This will then help them create a quotation and Risk Assessment and Method Statement for the job.
The basic components of any electrical system are the electricity meter, circuit breaker box and cables usually hidden in walls or ceilings. The meter is responsible for tracking how much energy the building uses and feeding it to the circuit breaker box. This then breaks up the electricity and directs it to different outlets, lights and appliances around your home or business.
Each circuit must be properly sized for the load it will carry. The size of a wire is determined by its gauge – the smaller the number, the higher the amperage capacity. Different kinds of electrical equipment require different kinds of wiring. Some are more sensitive to voltage peaks, such as computers, video systems or hi-fi equipment, so these can require special protection devices. Other devices, such as power sockets or lighting fixtures can be connected to the same circuit, although if you have a lot of energy guzzlers it may be better to separate them into their own dedicated circuits.
Conductors inside electrical cables are typically tinned to prevent them from becoming brittle over time. They’re also usually insulated to prevent them from coming into contact with each other or with the metal parts of switches, socket outlets and light fixtures. The insulation may be made of plastic, rubber or ceramic. The latter two were used with the early standardized “knob and tube” (K&T) wiring systems, which replaced older knob and tin can conduit in buildings.
K&T systems were designed to reduce the hazards of electrical shock posed by bare copper wires. This was achieved by insulating them in either ceramic tubes or by wrapping them in rubber. The latter also reduced the risk of fire by preventing oxygen from reaching the conductors through wood structural members. Over time, rubber deteriorated, though, and the conductors were often exposed at connections where they came into contact with switchboards and other electrical devices. The exposure to oxygen caused corrosion, which can lead to short-circuits. This is why today’s electrical installations have high-sensitivity residual current devices (RCDs).
Conduit and Fittings
Whether you’re rewiring an old house or running cables throughout a new commercial building, conduits and fittings help to protect electrical wires from environmental conditions. Conduits enclose and organize wiring paths while couplings, elbows and other fittings provide connection points. You can find electrical conduit in a variety of materials and in different sizes, and each type of conduit has its own specific set of fittings that work best with it.
The first step in planning a conduit run is to determine the length needed for the project. You can then use a conduit cutter or hacksaw to cut the conduit to size, ensuring that it is clean and smooth on both ends. After cutting, you’ll want to use a file or deburring tool to remove any burrs from the cut ends of the conduit. Next, install conduit supports to prevent sagging or movement in the wall or ceiling.
After installing the supports, you can begin to add in the conduit fittings that will connect your wires. Couplings join two sections of conduit, while connectors link a conduit to an opening in a junction box or enclosure. You can also find elbows, which allow you to turn the direction of a conduit run, and bends, which save time and money by making it possible to avoid the need for hand-bends.
Other types of fittings include flanged and threaded couplings, reducer washers and conduit nipples. Flanged and threaded fittings are designed to be inserted into the knockout in an enclosure, while reducing washers connect conduit to fittings of different diameters. The type of fitting you choose will depend on the environment where the conduit is being installed and the level of moisture protection it needs.
For example, if you are installing in an area that is wet or corrosive, you’ll need to install special electrical conduit, which is made from a corrugated metal material with heavy-duty insulation. There’s also flexible conduit, which is able to be field bent without the need for tools and is usually available in trade sizes up to 2 inches.
The cabling used in an electrical wiring system must adhere to a set of strict safety standards. Wire and cable types and sizes are limited based on circuit operating voltage, current capability, insulation type and thickness, temperature rating, whether it is installed in dry or wet locations and exposure to chemicals. Each circuit must have a protective conductor that provides a path to earth in the event of a fault condition.
The main cabling infrastructure is the backbone that connects all points of the wiring system in a building, including offices, warehouses, hospitals and retail outlets. The cabling can be made up of copper or fibre optics. The backbone is a key component of an electrical network, providing high speed connectivity and security. Cabling infrastructures can be structured, allowing easier troubleshooting and maintenance by standardizing hardware connectors and cable types. Structured cabling also simplifies telecommunications infrastructures by eliminating the need for multiple cables to carry the same data from different devices.
Standard electrical cable comes in a range of materials and is rated for its ability to handle electric current. It has a flat grey thermo-plastic sheath with two single conductors inside, one being brown in colour denoting its intended use as the ‘live’ or line conductor, and the other being blue which is used for the neutral conductor. Other options for cables include flex, which has a soft rubber or thermo-plastic sheath with individual insulated conductors that are flexible and can be re-routed without affecting the performance of the circuit. Cables with an additional layer of protection are also available, for example a ‘fused connection unit’ that protects the circuit from damage by overload. Another option is cable trunking, which is a pre-made, rectangular cable tray that provides easy access to the wires in a wall, floor or ceiling.
The electrical installation of a building must contain an electricity supply point, commonly known as a fuse board or consumer unit. This is where all the circuits in an installation originate, and it is from here that the power flows into each circuit. The fuse board/consumer unit must contain an automatic disconnection device that will disconnect the power if a fault is detected in the wiring system.
Cables need to be terminated to create a secure and reliable connection between the cables and the equipment or device they are connected to. Proper termination helps to ensure efficient power transfer and can prevent issues such as overheating, arcing, or insulation breakdown. There are several different methods of terminating wire cable, including crimping, soldering, and compression. Choosing the right type of termination for your specific cable and connector will help to ensure that it is installed correctly and that the connections are as durable as possible.
Electrical terminations are designed to interconnect two cable ends or a cable end with a terminal on equipment. They can meet both physical and electrical requirements, such as mechanical security and environmental fortification, as well as meeting electrical requirements like current carrying capacity and voltage drop. They are commonly found in datacom, telecom, and fiber optic applications.
It is important to know where cable termination occurs in your buildings because this will help you determine which cables are your responsibility and which are the responsibility of your service providers. This will also allow you to quickly identify any cables that need repairs, so you can get them repaired as soon as possible.
Generally, termination will occur where the cable meets a piece of equipment such as panels or wall outlets. These points are often referred to as demarcation points. In many instances, this is where the responsibility for the wiring system shifts from the builder or contractor to the service provider. It is important to be able to access these cables if there are any problems or if you need to upgrade your wiring systems.
Another common location for cable termination is at junction boxes, which are located on the exterior of your building. These are used to protect the wiring system from weather elements and other hazards, such as pests or intruders. It is best to work with these before the drywall has been installed, as it can be difficult or impossible to access them once it has been.
While working with power cables can be dangerous, it is possible to do so safely when the proper precautions are taken. Always follow safety guidelines when working with electricity and use the appropriate tools for each task. It is also a good idea to familiarize yourself with local building codes and power distribution standards before beginning any projects.