Electrical Adda

Classification of Protective Relays : Based on Technology : Relay Classification Relays are broadly classified into 4 types based on technology used in manufacturing and based upon mode of operation , Sensing the fault  and giving Trip indication to circuit breakers . These Protective Relays are used in HT & LT Applications ,  HT applications in 33 KV side and in LV side 440 Volts . ELECTRO-MAGNETIC RELAY  :  Works on principle of  Electro - Magnetic Attraction . Based on amount of current flowing in the coil , Electromagnetic force is developed that will be exerted on moving armature. There  are 2 types of Electromagnetic Relays Presently used in Industrial & Commercial  applications . Induction Disc Type Relay  . Plunger Type Relay . 1.1 Induction Disc Type Relay : Induction Disc type Relay Relay consists of 2 Electromagnets , Disc , Moving contact and fixed contact , plug setting multiplier . 2 Windings are connected to 2 electromagnets.  The Primary current carries Current

1. Distribution Transformer  Standard Ratings : Distribution Transformer 25  Kva       63 Kva 100 Kva 200 Kva 315 Kva 500 Kva 750 Kva 1000 Kva 1250 Kva 1500 Kva 2000 Kva 2500 Kva 3000 Kva 3500 Kva 2. Transformer Manufacturers : Kirloskar Electric  Vijai Electricals Volt Amp Crompton Greaves ABB Siemens Pete  3. Transformer Protection :  Overload , Overcurrent , Short- circuit .   Earth Fault .  Differential Protection .  Restricted Earth Fault .  Gas Detection .  Over voltage , Under Frequency .  Pressure Relief Device . 4. Transformer Core  : CRGO  Material  Amorphous Material  Mostly  Amorphous core Material is used in T/F  because  Reduces Core Losses , Magnetization losses  Total No load losses reduced By by 3% of full load losses. transformer Noise & Vibration reduced . 5. Transformer Oil  : Mineral oil which is free from fatty acids are used in transformer  Chemical name is Hydrotreated Light Nepthanic Distillate. low viscosity oil flash point at 140 degree centigrade . 6. T