Engineering Q&A
State and explain the faults occur in the transformers.
in Switchgear And Protection by

1 Answer

0 like 0 dislike

Sr. No.
Type of fault
1 Earth fault
Due to breakdown of insulation between live conducting parts such as winding, terminals etc. and earthed metallic parts such as core, tank etc. the current is diverted to earth, causing earth fault. The causes of earth fault are: i) Electrical breakdown of insulation due to overvoltage surges produced by lightning or switching operations. ii) Mechanical damage of insulation. iii) Electrical or mechanical breakdown of bushings iv) Insulation damage due to over-heating
2 Overloads/ Overheating
Sustained overloads cause additional losses in windings, causing over-heating of windings. Unbalanced loading cause additional magnetic losses leading to over-heating of core and other mechanical parts.
3 Incipient faults: Phase to Phase, Phase to ground, low oil level, decomposition of oil
Incipient faults are slowly developing faults, which if not attended in time, can lead to severe faults. i) Slow insulation degradation due to continuous overheating. ii) Reduction in oil level due to leakage, which leads to unequal cooling of transformer assembly, resulting unequal thermal expansion and stresses. iii) Degradation of oil over a period of service.
4 Saturation of magnetic core
Over-voltage conditions lead to saturation of cores. Since flux level is increased, the iron losses are increased.
5 Faults in tap changer
Mechanical problems in tap changer assembly lead to faults in tap changer.
6 Inter turn fault
When insulation breakdown of a winding takes place and few turns of the same winding are shortcircuited, the inter-turn fault takes place.

Related questions

1 answer
asked Sep 15, 2017 in Unit 1 by Quiz | 121 views
1 answer
asked Jul 21, 2019 in Switchgear And Protection by anonymous1 | 1,361 views
Welcome to, where students and teachers can ask and answer any question. Get help and answers to any engineering problem including Electrical, electronics, mechanical, telecommunication, instrumentation, computer, mathematics, physics etc. Get answers to questions. Help is always 100% free!

Most popular tags

power motor dc circuit transformer voltage current system used phase resistance factor ac load synchronous induction energy electric generator electrical series frequency capacitor between plant line speed transmission use meter type advantages difference single mosfet control function instrument problem magnetic diode amplifier high bjt machine unit source motors and diagram winding shunt field parallel define electricity torque value maximum time relay types arduino supply digital armature applications thyristor working transformers wave on flow operation three coil material instruments state ratio signal emf effect formula efficiency theorem method disadvantages starting microprocessor network test operating direction controlled different logic transistor single-phase scr loss temperature connected rc law force inductance compare measure station wire low conductor principle wattmeter full characteristics measuring constant measurement breaker losses device converter bridge linear materials nuclear matrix flux drive resistivity of machines angle switch free rectifier protection core circuits battery solar gain thermal loop generators open negative analog number lines friction basic reactance short gate pole inverter the conservation diesel iron resistors capacitance engineering using direct main electronic electronics a steam induced relays hysteresis universal transducer computer feedback range distribution work secondary igbt algebra pmmc plants factors capacitors dielectric controller regulation systems design air fault components rotor cable starter oscillator eddy alternator application semiconductor ammeter rl average forces damping rlc connection zener electromagnetic biasing minimum insulation pressure balanced permanent moving errors running copper self analysis impedance stability quality start ideal curve over commutation is 3-phase arc permeability peak bias error fuzzy commutator conductors superposition density mechanical rotation construction measured electrons charge memory inductive two transfer explain fuse methods off back three-phase tariff locomotive installation welding heating rms surge rating generation potentiometer coupled shaded rate capacity storage adc excitation active pure resistor harmonics reluctance microcontroller voltmeter inductor internal 8085 cro reaction insulating overhead hydro resonance traction definition breakers earth

9,199 questions

7,946 answers


3,292 users

9,199 questions
7,946 answers
3,292 users