mahendran


{ City } coimbatore
< Country > india
* Profession * electrical engineer
User No # 65009
Total Questions Posted # 1
Total Answers Posted # 5

Total Answers Posted for My Questions # 0
Total Views for My Questions # 1495

Users Marked my Answers as Correct # 16
Users Marked my Answers as Wrong # 14
Questions / { mahendran }
Questions Answers Category Views Company eMail

I WANT TO INSTALL LIGHTING ARRESTOR ABOVE 20 FEET HEIGHT INDUSTRIAL BUILDING. NOW IT WAS 15 FEET HEIGHT HOW MUCH DISTANCE IT WILL COVER & HOW TO CALCULAT THE DISTANCE COVER BY THE ARRESTOR

Electrical Engineering 1495



Answers / { mahendran }

Question { Birla, 11568 }

why not use capacitor in Dg sets.


Answer

normally d/g working time we monitoring ammeter only. we add
the capacitor the pf is increased and amps will become less.
so at this times we closely check the kw meter only this
will not increase to rated kw.

Is This Answer Correct ?    1 Yes 6 No

Question { 5509 }

what is max. continous current of LT side of distribtion
transformers? ie for25kVA, 63kVA, 100kVA, 200kVA etc


Answer

KVA=ROOT3*V*I/1000

I=KVA*1000/ROOT3*V

25*1000/1.732*420

I =34.6

SAME FOR ALL

Is This Answer Correct ?    13 Yes 1 No


Question { 4506 }

if our load is 65000 watts howcan we find out all char like
cable size. mcccb etc


Answer

KW = ROOT3*VI*PF/1000
65=1.732*400*I*0.9/1000
I=104

MCCB 1.5 TIMES THE AMPS

SO MCCB SELECT 160 AMPS

CABLE 70 SQ MM CU OR 120 AL

Is This Answer Correct ?    0 Yes 0 No

Question { 4419 }

power 148kw i need exat cable size in 148 kw in 3phase what
size of cable can i used.


Answer

1 kw = 2 amps ie 148*2=296 amps

240 sq mm will carry 220 amps you make 2 * 240 =480 amps
this is actual amps for safety we give 755 load to the cable so
240*75%=380amps

150sqmmwilltake 180amps ie 2*180=360amps75%load
360*75%=270amps its less then your load

so you can select 2*240 sqmm cables

Is This Answer Correct ?    0 Yes 5 No

Question { 4419 }

power 148kw i need exat cable size in 148 kw in 3phase what
size of cable can i used.


Answer

185 takes 200amps 2*200=400amps
load factor 75% 400*75%=300amps

you select 185 sq.mm cable 2 runs if the voltage is 415

Is This Answer Correct ?    2 Yes 2 No