What is the minimum setting in REF relay because i am
facing some problem whenever power resumes after power
failure my transformer is tripping because of REF trip. I
am using CSPC make numerical relay(DIP switches). Now
setting is 15 percentage. What is the reason for this
triping. I sm waiting for answer
Answer Posted / k.prakashchandra
Your setting is 15% of In.While charging ,Tr draws initial
magnetizing current 6 to 15 times the In. Any difference in
measurements by CT s at this current ,may exceed the set
current.Even 1% error in measurement at normal current
becomes 15% of In at initial charging current at 15 times
the In
| Is This Answer Correct ? | 0 Yes | 1 No |
Post New Answer View All Answers
I Just want do EHS Certified Certification Distance Course From Govt approved,so can any body provide me details.
Dry type transformers
neutral earth resistance testing is it possible for transformer while in load condition
What is the maximum and minimum rating of UPS?
i have applied for the post of RRB section engineering chennai board please send me previou papers and solved answer. my mail id jagarapusrinivas@gmail.com
Why generation voltage in thermal power plant is between 11kv to 33kv?
Difference between rating factor of cable and derating factor of cable?
size of condotory fron voltage level
How will you justify IR value and Charging voltage of any motor,transformer and Cables.......???? . . . . . . . . Plz tell me any body Baljeet Singh, engineer_89@refiff.com
how to determine Sq.mm size of finolex power cables.
sir i have cleared the apti test of EIL held on 15th march and my interview will be in new delhi on 2nd june.i will be very much helpful if u help me regarding the type of interview questions comes at EIL.(URGENT.........PLZZZZZZZZZZ...............)
What is difference between mcb and mccb.
During Testing of Maintenance Free Earthing, How deep should be the Spikes of Earth Test Meter should be inserted in the soil(one spike is 15 Meter & Other spike is 30 Mtrs away from the Main Earth Electrode. Because, recently, we observed that when spike is inserted 3-4 Inch in the earth- results are better, If spike is inserted 1 feet deep than results are increasing.
Explain M Var? Which types of problem occurs when reactive power increase at the time of full load of plant and at the time of synchronize of plant?
why the starting voltage drop in a cable needs to be limited?what is percentage of the voltage drop allowed during starting?