Answer / ramachandran_pb

over current protection
earth fault protection

Answer / vipin joshi

1.. low lube oil pressure (2.5 to 7.5 kg/cm square)
2..high coolant water temperature (95 Celsius)
3.. low coolant level 80 %
4.. overspeed (1480 to 1580)

wat is power factor

7 Answers   IOCL,

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how to test power transformer.YNd11

0 Answers  

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We have one 500KVA transformer. We have tested REF relay and commissioned. After one and half year, due to some ground fault in one of the DB circuit Transformer tripped by REF relay. What will be cause and remedy. Please advise?

1 Answers  

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what is voltage gradient?

8 Answers   Bhel,

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What are the two segments of nyquist contour.

0 Answers  

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How do we calculate Blower drive Power (kw) If we have Volume m3 and Pressre (mmWC)

1 Answers  

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How one can check the faulty capacitor, diode when connected in the circuit ? and when you can not take them out ?

4 Answers  

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From past few months I am getting lagging pf even though sufficient capacitors used in circuit. Where is the problem pls answer

0 Answers  

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why we don't use earthing as neutral?

1 Answers  

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On load tap changer (OLTC) explode? Transformer Vector group: Ynd11 Rated Power: 353MVA Rated Current: 693A Voltage:294/20KV OLTC Type: T III Y1000 110/c 12193w Max Operation Current: 295A Step Voltage: 550V Arrangement in Tx windings: Y Connection Problem: Damage of Unit 1 Generator Transformer On Load Tap Changer (OLTC) Description of Incident: 9.00 a.m. :- Generator No Load test on excitation system started 10.30 a.m :- Carried out AVR change over test 11.30 a.m :- Preparation for Generator Manual Synchronizing test 12.00 a.m :- Manual Synshronizing test started. Observed incoming generator voltage higher than running voltage. CECR operator operated Generator Transformer OLTC to bring down the incoming generator voltage 12.03 a.m :-Generator Transformer abnormal alarm operated at Gen.Control Desk (CECR) CECR operater at Generator transformer bay informed that the transformer oil splashed out from OLTC. CECR operater informed that he heard explosion inside OLTC. Observed Oil level & Oil Flow alaram operated at Tranformer local annunciator. 12.05 am :- CECR operator 'Open Gen Field Breaker” 12.10 a.m. :- Elec1 team inspected the OLTC and found the OLTC rupture disk was broken and oil spilled at OLTC area. - Elec1 found the OLTC top cover bulging. Do anyone know why and possibility cause happen in this OLTC.

9 Answers  

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New istallation how many eathing have one transformer? Names of earthing connect places?

10 Answers  

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how DC is differ from AC ? what are the difference between them ?exept (P-N)&(+__-)

2 Answers  

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