Answer / raj patel

star connection eliminate multiple of 3 harmonics because of its phase sum at that point makes it zero. and same case for delta connected winding it is that phasor sum of current for multiple of 3 harmonics get zero. So without any special arrangement it is inherent capability of star and delta connection to eliminate harmonics that are multiple of 3.

HOW TO CONVERT SQ MM OF A CABLE TO DIAMETER, EG. CABLE SIZE IS 185SQ.MM WHAT IS THE DIA OF THE CABLE??????????????

3 Answers   Parsons, SWAN,

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why do mostly prefer to generate and distribute electricity in 3 phase..not in 4 phase or 5 phase.??

5 Answers   BSBK, IOCL, NTPC,

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why the earth pin is thicker than other pins in a plug? If it is for reducing resistance, then why the copper earth wire is not so thick as earth pin of socket?

5 Answers   Omax,

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Which lamp will fuse first(1)20(2)40(3)200 three lamps will fuse together

2 Answers   NTPC,

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what is meant by power and distribution transformer ?

0 Answers   CG,

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what is the difference between circular wdg & ractangular wdg?

0 Answers  

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We have drive feeding an output contactor for a 5000 hp motor @ 5kV application. The motor FLA is 629amps x 1.25% service factor = 786.25 amps The cable that we current have in place between the drive and the output contactor is 350kcmil- MV-105 (parallel cables). Per the NEC table 310.60 (C) (69). This show the cable ampacity is at 615 amps per cable for a rating of 1230 amps. We have derated the cable for the cable tray and the multiple cables application and our calculations show that after the correction factor factor we are at 922amps. 1230 amps x .75% correction factor factor = 922.5 amps. The customer is driving us to then use another safety factor of .25% off of the already derated cable. Can you please provide a longhand calculation for your solution on this application?

0 Answers   Siemens,

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Explain with example of functional requirements of protection relay in terms reliability, selectivity, sensitivity

0 Answers   NCC,

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star delta advantage and disadvantage?

2 Answers  

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megger how much voltage will produce ?

4 Answers  

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what is mean by transition resistance of transformer?

0 Answers  

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what is cogging? how it can be controlled?

1 Answers   HCL,

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