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 / ramji
The differential protection is used for protecting the
transformer from internal winding fault,internal winding
shorts etc.,.It operates through three sets of CT's
connected in and out of transformer.It may or may not
operate during minor earth faults.REF is used to detect the
earth fault at restricted zone where its protection CT is
connected.It will surely operate during earth fault.But not
in windings short.
| Is This Answer Correct ? | 31 Yes | 4 No |
Post New Answer View All Answers
ELECTRICAL ENGINEER TEST IN FEWA ANY ONE HAVE KNOWLEDGE ABOUT THIS?????????
we have two generators different capacity on 15 MW and other 6MW at 11 KV , 15 MW gen. bus short level current 40KA,and 6MW short level current 25KA,, length of cable 100MTR between 6 MW from 15MW gen. for bus coupling . kindly tell any one can we use both NGR OR one NGR from any GEN. BOTH NGR has diff. rating. Tariq pakistan
What are the advantages of hydropower?
what happend to DC shunt motor if its field winding insulation becomes slightly weak? will that motor can run on full load or not explain in detail. thanks
design a LV scheme for a 15 storied building?
Dear all: Recently we got a question about Interface between PMS and SAP-PM.once we got a update message from PMS.we should set the deletional flag for functional location in SAP system.Is there any FM or BAPI to use?There are only functional location create and change provided by SAP. Best regards!
why we have to particulary use ACB for below ratings,even available of MCB,MCCB with that range ?
Sir, I m 3rd year student 4m DCE and want to do internship in siemens or l&t or any other mnc related to electrical engineering. please tell me the procedure 4 same and oblige me
i am electrical and elctronics engg passed out in 2009 want to attend for reliance placements.plz send me apttitude ,technical and hr question answers to my mail plz. my mail id-kat.bindas@gmail.com
33kv Rated output avilable in market (any where in india)
While testing LA mast,What are the parameter limits ?
Is there any rule to select the voltage of motor based on KW rating? What is the rating above which lt motor becomes the HT motor?.
WHERE NEUTRAL WIRE IS CONNECTED AT DOMESTIC TO TRANSMISSION LINE(SINGLE PHASE TO THREE PHASE)
Explain cmrr?
How to know about the rating(voltage and other) of induction motor if its name plate is missing at the manufacturing site.