in our 6.6kv motor feeder[it is having two sources from Bus A&B] earth fault relay is acting, we checked CBCT connection and cable meggerd values found very good still earth fault acting during first two are three start after that it will hold. please clarify what was the reason. if same motor is starting from other Bus-A it will start.

1 Answers   Gasal, Voltech,

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TCS IS IT COMPANY THEN WHY DO THEY NEED ELECTRICAL &ELECTRONICS ENGINEERS?

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Describe the test procedure to determine the vector group

0 Answers   MPSEB,

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how to calculate the slowness and fastness of energy meter if we have different kw load for example (0.746 kw and meter rev constant 400 and we calculate the 2 rev in 30 sec) please explain the formula thanks

1 Answers   WAPDA Water and Power Development Authority,

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what is the problem with single phase AC motors and how is it overcome?

2 Answers  

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what is the purpose of bypass mode in energy lighting transformer?

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Which type of DG need Netral Earthing?

1 Answers   Hyundai,

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which one is rotating transformer-single phase induction motor or 3 phase squirrel cage motor?

1 Answers  

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kVA rating of ordinary transformer is increased when connected as an auto transformer because A transformation ratio increased B secondary voltage increased C energy is transferred both inductively and conductively D secondary current increased

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Transformer Secondary maximum current (max. load)

3 Answers  

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1. What is differential relay? How it operates? 2.How to calculate the Short Circuit Impedance in Transformer? 3.What is the alternate solution for testing of polarity by using polarity tester while its milli ammeter does not works? 4. While testing the 33KV Busbar by using Hipot kit, what should be the test voltage we have to apply? 5. What is the procedure/activities to be taken to inject the current more than 2000A by using 2000A Loading Transformer? 6. Explain how you can give the overload setting to any Motor Protection Relay for a HT motors with formula and example? 7. Why restricted earth fault protection is needed? Why can’t differential Protection is sufficient? 8. What should be the minimum and maximum ohmic value for earthing? 9. Why DC Currents are not used in transformer? 10. What is the Frequency while we step up the voltage from 220V to 11KV? Is it possible? Explain it?

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how many types of Earth bits available

1 Answers  

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