Wiring & Regulations PDF

WIRING & REGULATIONS WIRING MATERIALS AND INSTALLATION Electrical wiring needs expertise attention to every building projects. It directly related to the safety of human beings and utilities / equipment people handle. The scope of electrical wiring shall cover supply, installation, testing and co...

WIRING & REGULATIONS WIRING MATERIALS AND INSTALLATION Electrical wiring needs expertise attention to every building projects. It directly related to the safety of human beings and utilities / equipment people handle. The scope of electrical wiring shall cover supply, installation, testing and commissioning of all conduits and accessories, wiring, switches, socket outlets, spur outlets, junction boxes / pull boxes, GI pull wires, ceiling roses making connections etc. 1. CONDUIT WIRING AND INSTALLATION METHODS Conduit wiring is a system of wiring using tubes (pipes) either steel or PVC, to provide good mechanical protection for its conductors drawn inside the tubes. It also gives high degree of protection from fire hazards to its conductors. Conduit pipes will be installed on the surface of walls or roofs by means of saddles or hooks or concealed inside the wall or roof or floor. Modern building construction adopts conduit wiring (PVC conduit or GI conduit both in various mechanical strength depending on site requirement and project specification) and found mainly in two types: 1) Surface or Open type conduit installation, and 2) Recessed or Concealed type conduit installation. Why Use Conduit Wiring? When you are ready to start your wiring you first have to decide what type of wiring you will use to complete the job at hand. Some wire has its sheath coating, requiring only that it be stapled to wall studs and joists to secure it and the use of conduit are the most common. Protecting Wires from Damage Conduits come in styles from fairly strong construction to extremely rigid conduit that you could drive over without damaging it.You will have to choose the conduit that both satisfies your needs and is appropriate as per the National Electrical Code. PVC conduit - is often used in underground and wet location applications. This type of conduit has its PVC fittings, connectors, couplings, and elbows. They are easy to attach with a cleaner and PVC glue. Since the PVC conduit is not conductive, you should always run a green ground wire in the conduit for proper grounding methods at connection points Flexible metal conduit - a type of conduit that is great for areas that require tight bends and close quarters would make it difficult to bend regular conduit. Water heaters, can lights, and attic vents are great examples of typical flexible conduit installation. Electrical Metallic Tubing – or EMT conduit is lightweight, easy to bend, and is used within the walls. It also is easily damaged, unlike IMC or RMC/RSC. Intermediate Metallic Conduit - or IMC conduit is a thicker conduit that is galvanized, making it a great choice for outdoor installations. This is also a good choice for exposed walls in basements, garages, outbuildings, and areas the conduit can be hit or damaged. Rigid metal conduit - is the thickest and heaviest of all. It can be used to run wires under driveways, service feeder installations, and other more extreme condition areas. Rigid conduit must be threaded on the end and is more expensive than the other conduits listed. Most utility companies like you to install rigid conduit as the service entrance piping to ensure the strongest and best installation that can protect the wiring and that will be able to withstand wind, falling branches, and storm damage. Electrical Wiring Systems and it’s Methods The electrical wiring must be installed correctly and safely in accordance with electrical regulations and standards. If the electrical wiring is carried incorrectly or without confirming to any standard, devices could damage or leads to the malfunctioning of device which further causes for the reduction of device life. Several factors have to be considered before the actual installation work to be done for residential, commercial or industrial wiring. These factors include type of building construction, type of ceiling, wall and floor construction, wiring methods, installation requirements, etc. Individual conductor systems for general use: 1. Open wiring on insulators – a type of wiring method that is functional enough to be used as temporary wiring. This wiring provides protection Porcelain Tube and supports with flexible mica tubing, porcelain tubing and cleats when making bends and wire termination. Porcelain Knob 2. Concealed wiring - is similar to the open wiring on insulator except that the conductors are concealed in hollow spaces of walls and ceiling Convenience outlet of buildings. Bore holes in stud Raceway system for general use: 1. Flexible metal conduits – used instead of rigid conduits where numerous elbows, offsets and limited working space is required. Flexible Metal Conduit 2. Underfloor raceways – are usually used in buildings that are fire-resistant. Tray PVC 3. Cellular metal raceways –are used in a cellular steel floor with hollow cells from the raceways. These cannot be used where conductors are bigger than #0. concrete cables 4. Wireways – provide convenient metal raceways for conductor sizes up to 500,000 circular mils. wires 5. Busways – are mostly used in industrial plants because of their adaptability to future needs and relocation or revision of production lines. 6. Surface metal raceways – (metal molding) – are frequently used to install additional outlets in buildings previously where concealment of conductors is difficult. 7. Non-metallic conduit (PVC) – is commonly used in industrial plants where corrosive liquids are present. It simplifies the conduit layout when obstacles are encountered. Cable assembly system for limited use: 1. Service entrance cable – is a form of armored or non-metallic sheathed cables used for service entrance only. 2. Non-metallic waterproof wiring – used in cold storage and wet location where corrosive fumes and vapors are present. 3. Non-metallic extensions – additional outlets may be installed from an existing outlet by means of these extensions. 4. Underplaster extensions – used when additional outlets are installed from an existing branch circuit. Thank you!