Introduction to Electricity

Electricity is generated from the motion of tiny charged atomic particles called electrons and protons.

Protons = +Electrons = -

In September of 1831, Michael Faraday made the discovery of Electromagnetic Induction.

Faraday attached two wires to a disc and rotated the disc between the opposing poles of a horseshoe magnet creating an electric current.

Energy from one of the sources is converted by machines at the power plant to Electricity and then put onto the Electric Power Grid

Factors to be considered during choosing type of wiring:

Durability

Safety

Appearance

Cost

Accessibility

Maintenance Cost

Cleat Wiring (Vulcanized Indian Rubber wire known as V.I.R. wire in cleats)

Advantages:Easy installationMaterials can be retrieved for reuseFlexibility provided for inspection, modifications and expansion.Relatively economicalSkilled manpower not required.

Disadvantages: Appearance is not good Open system of wiring requiring regular cleaning Higher risk of mechanical injury.

In this type of wiring, insulated conductors (usually VIR, Vulcanized Indian Rubber) are supported on porcelain or wooden cleats.

cheapest method of wiring.normally used for temporary work.

It consists of insulated conductors laid inside rectangular, teakwood boxes having grooves inside it.The system is suitable for indoor and domestic installations.

Advantages:Cheaper than lead sheathed and conduit wiring.Provides good isolation as the conductors are placed apart reducing the risk of short circuit.Easily accessible for inspection and repairs.Since the wires are not exposed to atmosphere, insulation is less affected by dust, dirt and climatic variations.

Disadvantages:Highly inflammable.Usage of unseasoned wood gets damaged by termites.Skilled workmanship required.

Wood Casing Capping Wiring (V.I.R. wire in wooden casings)

Tough rubber-Sheathed (T.R.S.) or PVC Sheathed cables are suitable for this type of wiring.Usually the cable is laid over wooden batten which is fixed on the wall.Link clips are used for family clipping the cables in position.Tinned steel or aluminum clips are used.

Batten Wiring

In this system PVC (polyvinyl chloride) or VIR cables are run through metallic or PVC pipes providing good protection against mechanical injury and fire due to short circuit. They are either embedded inside the walls or supported over the walls, and are known as concealed wiring or surface conduit wiring (open Conduit) respectively.

Conduit Wiring (V.I.R. conductors run in metallic conduits)

The system is best suited for public buildings, industries and workshops.

best system of wiring.most desirable for workshop and public buildings.provides mechanical protection, safety against fire and shock if bonding and earthing are well done.

PVC Conduit

Plastic conduits are the PVC conduits. PVC is polyvinyl chloride, a synthetic thermoplastic material made by polymerizing vinyl chloride.

moisture resistant and noncorrosive, making it the best option for underground routing. smallest being of ½ inch internal diameter and the biggest being 5 inches. The thin conduit is well suited for concrete and the large diameter conduit pipes are better for exposed and open locations as they can be buried directly.

Electrical Metallic Tubing

Metal conduit is metallic tubing and is also known as thin wall conduit. more affordableit is non water resistant and can be affected by corrosive materials. This limits this conduit to being used indoors where it is dry. They range in size with the smallest being of ½ inch internal diameter to 4 inches.

Rigid Metal Conduit

Rigid metal conduit can appear similar to metal water pipes but it is easier to bend due to it being softer with an internal finish that is smooth for easy gliding and passing of cables and wires. They range in size with the smallest being of ½ inch internal diameter to 6 inches. The most common material it is made of is steel. Copper alloy and aluminium are used in locations where high corrosion is inevitable. Indoor locations that are dry can utilize conduit made of black enamel steel. For outdoor locations, conduit made of galvanized steel is used for its protecting quality against rust and damage.

Flexible Metallic Conduit

Metallic conduit also comes with flexible quality. These are known as “Greenfield conduit.” Due to its flexible quality, this conduit type is used in awkward areas and locations and in between where rigid conduit is difficult to bend. Flexible metallic conduit can also be used where some give is required where moving machinery can create vibrations. They range in size with the smallest being of 3/8 inch internal diameter to 4 inches.