Electrical Engineering Technology

    INDEX 1. Wire size 2. Two way switch connection 3. Intermmeadate switch connection 4. Tests   to be made on a new electrical installation befor   it is switched   on to the mains ? 5. How one light control   in Five plase? 6. Why Earthing is require Transformer Neutral? 7. How is a Amp if load 2000W? 8. What is a Cos@ 9. Star Delta Connection 10. Why Neutral not present   in the Delta Connection 11. Why Star/Delta Startor use for ? 12.Typs of Pannel 13.Internal Connection of DB 14. If maximum No circuit B7 which No of   Circuit Connected in the   DB? 15.Type of Earth? 16. How to Earthing Test? 17. Corridor Lighting? 18. Type of house wiring? 19.Types of Wire Joint? 20.Type of   Switch 21. Size of Gland? 22. Drawing Scale?   v   1.Wire Size          0.5, 0.75, 1.0, 1.5, 2.5, 4, 6, 10, 16,   25, 35, 50, 70, 95 Sq mm.   Cable size             0.5, 0.75, 1.0, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 240, 300,

A light-emitting diode (LED) is a semiconductor device that produces light from electricity. LEDs last a long time and do not break easily (compared to incandescent lightbulbs). They can produce many different colors. They are efficient - most of the energy turns into light, not heat. (1) An LED is a type of diode that makes one color of light when electricity is sent through it in the expected direction (electrically biased in the forward direction). This effect is a kind of electroluminescence. (2)  The color of the light depends on the chemical composition of the semiconducting material used, and can be near-ultraviolet, visible or infrared. (3) The color affects how much electricity is used by the LED.  (4)  A white LED has either two or three LEDs inside, of different colors. Some white LEDs have one single-color LED inside (usually blue), combined with a phosphor that converts that single color to white. Ds are used in many places. They are the colored indicator ligh

         Totally enclosed Rising mains are with aluminium bus - bars or Copper bus-bars in suitable sections which are connected to make a vertical run. Each sections is provided with a number of wall straps for fixing  the  rising mains to the wall. The trunking consists of side channels of 14 SWG MS sheet and front and rear cover of 16 SWG to form totally enclosed metals clad construction.          The bus-bars of rectangular sections of wrought aluminium with a current density not exceeding 1.25 A per squire mm and are individually insulated with a non-deterioating material so as to prevent  any possibility of electrical fault due to presence of vermin. The aluminium bus-bars conform to IS 5082 -1969 grade 9-1 EQP. The total run in sectionalized and each section is fitted with a thrust pad to prevent the bus-bars from sliding downwards. Each section also has an expansion joint to take up expansion of that section.  2500 A bus -bars  Bus bar rising arrangement          Connections be