Answer / pratheesh

In previous days, efficient speed control of AC motor were
very difficuil. And also to run the AC motors at very low
speed also very difficuilt. Thats y in those days we used
DC motors expecially in traction system.
But with the arrival of VFDs for AC motors, we can use AC
motors also for low speed application efficiently.
And also the maintenence of AC motors are very very less as
compared to DC motors which has commutators and bruches.

Answer / vinod

because of the high torqure requirement.
now a days the motors are converted to ac

Answer / ganesan

it might use for our convenient of speed control we are
using variable frequency drive.the AC drive when compared
to DC drive so many advantages like better speed
control,less cost,accuracy,simple contruction etc.

Answer / vinay

DC DRIVE AND MOTOR NEEDS PERIODIC MAINTENANCE,AS IN AC
DRIVES AND MOTOR IT IS LESS.ie TO AVOID THE DOWN TIME OF
THE SYSTEM ALSO AC DRIVES AND MOTORS ARE USED

what is AB switch???

6 Answers   NTPC, Simplex,

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What is the difference between single point and double point bonding. please kindly detail about bonding of cables.

0 Answers  

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My system is 22kv/3.3kv transformer. client is asking to use NGR, but as we have dedicated Neutral Earthing systems which has a value less than 1 Ohm. So i want solid comparision. Why i should not use NGR as my system is already protected.Can any one help me to get out of this.how should i reply on basis of some great comparision and calculations. Please help

2 Answers   Ariel,

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what purpose of the percentage impendance in transformer

3 Answers  

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what is the difference between synchronous generator & asynchronous generator

4 Answers   Reliance,

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can anibody tel me on what basis the transformer vector groups are determined????

1 Answers  

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what principle the cabel TV channels are transmitted? will you be able to check the power at the connector behind your TV with a tester?If yes what is the supply level?

1 Answers  

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How to know motor winding is star or delta connected without see the information table and winding connection ?

5 Answers   NTPC,

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Tell me about yourself. ……………………………………. Why did you leave your last job? What do you see yourself doing five years from now? Ten years from now? What are your long-range career objectives? Why did you choose this career? How well do you work with people? Do you prefer working alone or in teams? How would a good friend describe you? What would your last boss say about your work performance? Why should I hire you? What makes you qualified for this position? What do you think it takes to be successful in a company like ours? In what ways do you think you can make a contribution to our company? What's the most recent book you've read? What two or three accomplishments have given you the most satisfaction? Why? Describe the most rewarding experience of your career thus far…………… Why did you decide to seek a position in this company? What can you tell us about our company? What do you know about our competitors? What two or three things are most important to you in your job? Are you willing to travel for the job?

0 Answers  

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What is meant by RVT and NDR ? expansion and details of it

0 Answers  

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What is annunciator ?

1 Answers  

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Capacitor is load free component but why ampere meter shows current when capacitor bank breaker close?

0 Answers  

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