Answer Posted / pankaj
DC supply used for control ckt because the system which we are protected by fault(i.e. o.c.,earth fault etc.)is working on A.C. at 50Hz frequency,if their is any fault & if our control system is also same on A.C. then we cant protect the H.T.line.
Hence D.C.supply which are not dependent on A.C.
(i.e.Storage Battery)is used for control ckt.
| Is This Answer Correct ? | 3 Yes | 4 No |
Post New Answer View All Answers
What is the formuala to calculate the rating of motor protection circuit breaker
how are reversing the direction of dc motor
what is size of 3phase 4wire cable to be used for 11 ton ductable A.C and how to calculate cable size for different load
Hello to all, Please someone can send me HPCL ELECTRICAL Engg. Sample papers to me? Its urjent....my email address is.... raviasiapacific@gmail.com
What are root loci?
hi i will D.E.E.E.is completed pls send rrb diploma old qustion papaer sent in my e mail. i.d.
Why transformer used in UPS??
What are the causes of unbalanced current on 34.5kv feeder Ia=0.05,Ib= 0.25, Ic=0.15 and In=0.27 prior to tripping current are balance?
following are the questions asked in interviews: 1) Considering the short circuit fault, which switchgear is preferable, SFU OR MCCB? Which operates faster? whicg one is popular in Indian Market and why? 2)Define SCPD. What is type2 coodination? 3)Why the contactor rating is higher for the fuseless selection than for fuse selection? whether the ratinf of SFU or MCCB remains the same in both the cases? 4)If the HP rating is known then can you calculate the ratings of L.V Switchgear(SFU/MCCB, contactor, OLR) without using the selection chart?
8. A DYNAMOMETER TYPE WATTMETER RESPONDS TO THE.......
what is the use of power transformer in GSS.
Define availability (operational)?
HOW WE CALCULATE CURRENT IF THERE ARE NOT PRESENT ANY AMMETER OR MULTIMMETER??????
Explain about Dubai electrical sysaem? Explain about Dubai drinking water system? Explain about Dubai Burj tallest building Electrical,Water.etc.. maintenance system?
1.What is the range of stator resistance of 3-phase induction motor? 2.Two electrically operated vibro motors are foxed in parallel direction in vibrating feeders. what is the direction of both vibro motors?