the single phase voltage is 230 volts and threee phase is 430 v.why three phase is not 660 v?

2 Answers  

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what happens if we earth negative electrode of an rectifier transformer used in ESP. In which normaly positive is earthd from inside the xmer.

1 Answers  

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what is the difference between UPS & Inverter

7 Answers   HAL,

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What is difference between potiential,volatge and emf

1 Answers  

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What is a HRC fuse (Full form)

26 Answers   Gammon, HRC, Moser Baer,

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How to calculate cable size for a particular load? i have 12 MW,11KV Motor 3 Phase, what should be cablesize? What are the points to remember for cable sizing calculations?

2 Answers  

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In our domestic single phase line if you don't have a ground connection (earthing)how will you separately use earth in a specific power supply board.

1 Answers  

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Why DC excitation is used for alternators? Why cant it be AC?

35 Answers   ABB, Ace Info, Alstom, Shalivahana Power,

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what is load shedding

4 Answers   KSEB,

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A commercial Building is designed with 14th floor levels with indoor substation of three phase transformer with rated capacity of 1000 Kva.The transformer delivered 65% of its rated capacity at 0.67 power factor lagging.Because of low power factor, the power customer was penalized and certain cost was charged accordingly based on every point percentage lower than 85%.This situation may repeatedly happen on the succeding energy bills of power customer.The power customer is desired to improve its historical power factor of 0.67 lagging and no further penalty be impose by the local power company on the next bill. Q: Identify the appropriate solution you want to offer to Client?.Justify SCIENTIFICALLY and MATHEMATICALLY the principles behind the solution.

0 Answers  

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What is meant by celling voltage & current in excitor ?

0 Answers  

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need to make a report. Need to choose a 3phase induction motor. Load conditions motor will operate in : Maximum Load: 30 Kw Speed: 2950 rpm Ambient temp: 20 cent Supply voltage: 440V Frequency: 50Hz need to look for the safety factor when choosing the motor, went through catalouge found a few, but dont know how to choose the safety factor allowing an extra load something above 30 KW to avoid any harm.

0 Answers  

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