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stanley


{ City } coimbatore
< Country > india
* Profession * electrical eng.
User No # 29766
Total Questions Posted # 5
Total Answers Posted # 8

Total Answers Posted for My Questions # 31
Total Views for My Questions # 84074

Users Marked my Answers as Correct # 270
Users Marked my Answers as Wrong # 101
Questions / { stanley }
Questions Answers Category Views Company eMail

How can calculate the efficency of the rectifier. input 240V AC, current 5 amps,P.F 0.98, Output is 54 V DC,62.6 A.

 10 Electrical Engineering 27832

To check the earth condition (In plug points); the voltage between earth and Neutral is in below 5 volts. Is it correct

 6 Electrical Engineering 9485

Dear all, How will we calculate the Diesel engines ( generator) efficiency considering fuel

 1 Mechanical Engineering 4141

FRIENDS, I am doing DEEE (part time)final year. Give me some ideas for project

HCL,

5 Electrical Engineering 9977

What is the difference between Dielectric and Insulator

 9 Electrical Engineering 32639



Answers / { stanley }

Question { 25748 }

1. What is the difference between ac induction motor
and ac synchronous motor?


Answer

Above answers are ok.

If you want more, get diploma 4th sem Electrical machines 2
book.
You have get clear knowledge about the motor

Is This Answer Correct ?    14 Yes 14 No

Question { Reliance, 26542 }

How to calculated capacitor rating both HT


Answer

capacitance of the capacitor is mentioned in KVAR.

Formula : KVAR = KW*tan@

FOR tan@, First note the power factor & KW without
connecting capacitor.
The noted power factor is in cos@.Convert the cos@ value in
tan@.
for ex. If power factor is 0.6, KW = 200
cos@ = 0.6
cos-1 (0.6) = 53.1
tan (53.1) = 1.333
200*1.333 = 266.6 KVAR
if you use 266 KVAR capacitor, Then the power factor
improves to unity (1.000).

Is This Answer Correct ?    20 Yes 12 No


Question { 9640 }

what is ohms law?


Answer

the previous answer is absolutely correct.
ohms law is defines the relation between resistance,current
and pottential difference.
OHMs LAW : At a constant temperature potential difference
is proportional to the current flowing through the
conductor and inversely proprtional to the resistance.

Is This Answer Correct ?    8 Yes 2 No

Question { 12660 }

If we connect the capacitor banks for DG set for maintainig
the power factor, it will effect to alternator
windings??????????


Answer

The cable between terminal to capacitor will burn if we
connect additional (external) capcitor.

Is This Answer Correct ?    5 Yes 8 No

Question { 27832 }

How can calculate the efficency of the rectifier. input
240V AC, current 5 amps,P.F 0.98, Output is 54 V DC,62.6 A.


Answer

Dear Mr.swapnil,

you have given the formula as P=VI*PF for both
input and output.
You should remember that the pf is not considered in the
DC (output of rectifier).

MY PROBLEM IS, OUTPUT POWER OF THE RECTIFIER IS GREATER
THAN INPUT. SO THE EFFICIENCY IS MORE THAN 100%. But the
efficiency must be with in 100%.

Any way thank you for your answer.

Is This Answer Correct ?    5 Yes 2 No

Question { Cushman Wakefield, 57371 }

how to calculate the battery Ah? what is the formula.


Answer

AH = Amps x hours.
If we use 15A from a battery of 1000AH, then we use upto
66 hours. (i.e., 66x15= 990 ). Th duration of usage is
decreased according to high amps.

Is This Answer Correct ?    160 Yes 44 No

Question { Cushman Wakefield, 57371 }

how to calculate the battery Ah? what is the formula.


Answer

The question is about the battery. The battery had only DC
voltage source.
In dc, no power factor.

Is This Answer Correct ?    56 Yes 19 No

Question { Siemens, 13802 }

Any one Give me formula for to increse the power factor,
0.8 to 0.95, How much the KVAr Required


Answer

pls verify the whole questions. i just already give the
formula with examples.

Is This Answer Correct ?    2 Yes 0 No