why we use REF and Differential Protection in one
transformers?my doubt is both protections are operated in
internal fault only.why we want to use 2 protections?please
clarify.
Answer Posted / ashish
as per my knowledge ref protections hav to be assigned
separately on both sides of traffo it protects 90% of
winding.
it is unit protection and its very sensitive.
while talking about diff protection two cts in each phase
on both sides of trafo is there any diff in incoming and
outgoing current will leads to trip so both are equally
required.
| Is This Answer Correct ? | 1 Yes | 2 No |
Post New Answer View All Answers
if in 3-phase system voltage=440V,frequency=60Hz, current=400A. then if it is single phase then current=? and if it is single phasing then current=?
how to calculate the fault in substation
what are the usual topology of transformers at different substations in the power system and why that particular topology is choosen. what are the limitaions of that topology?
difference between the applicability of nortons and thevenin theorem
i have 90kw motor.so i choose connect cable .please what is parameter checked so please give to formula
What is negative sequence over voltage element?
sir my exam is on 19/6/2013 under electrical branch pls send me sample aptitude questions as well as sample technical questions for jindal steel and power company
What is the function of electron gun assembly used in crt?
any application of back emf
Hi all I had applied for the RRB test in the ELECRICAL category. I would be pleased if any of you can sent me previous year question papers. Please forward the question papers to varshashahi@yahoo.com Thanks and regards Varsha
hi friend i am going too attend for hpcl in this month please help me by sending written test question papers i am in the stream of E.E.E
IN MY SYSTEM THERE IS ONLY OVER CURRENT EARTH FAULT RELAY IS AVAILABLE. FOR THE UNBALANCE SENSING IS THERE ANY RELAY IS AVAILABLE? THE SAME CTs WHICH ARE USED FOR THE OVER CURRENT EARTH FAULT RELAY CAN USE FOR UNBALANCE ALSO?
What are the different sign conventions used in electric circuits?
I have been using an 600VA with 0.6 p.f UPS with my desktop which has 450W power supply unit. Can anyone explain how can this happen . Because the output of the UPS is 360W (600*0.6) (<450W)
why on axial hitting up of air blast on hydrogen produced in oil circuit breaker,temperature rises of the core of the arc?