What is the minimum setting in REF relay because i am facing some problem when

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

Question Posted / ee_moorthy

2 Answers
4987 Views
I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

What is the minimum setting in REF relay because i am facing some problem whenever power resumes a..

Answer / k.prakashchandra

Increase the time delay

Is This Answer Correct ?

0 Yes

0 No

What is the minimum setting in REF relay because i am facing some problem whenever power resumes a..

Answer / 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

More Electrical Engineering Interview Questions

WHY BLADE & JOW OF ISOLETOR IN SUBSTATION?

1 Answers BRG, Voltech,

i am using star-delta connections with reverse/forward direction motion of the 75hp induction motor.What should be the ratings of Main,Delta and Star contactors and why?

1 Answers

in non technical way how can u define POWER FACTOR??

0 Answers

what is the d/f b/w dol & star delta starter.

2 Answers

what is RCBO?

1 Answers

why we use ac as a electric appliance in home or daily use?

1 Answers MNC,

How to select the cable and voltage drop in circuit?

0 Answers DEWA,

What is the difference bet ween EDO Type & MDO type ACBs, and what is the advantage EDO Type over than MDO type ACBs.

2 Answers Siemens,

In induction machine when the load increase the current will increase .why? what is the relation ship between the sleep and current drown by stater?

1 Answers

hi pot test principal

1 Answers NTPC,

How to select, design,size & calculate for 11 KV/33KV/66KV/132KV/220 KV/440 KV circuit breaker for HT side of transformer protection/HT distribution protection?

0 Answers Panacea,

HOW TO CALCULATE HV TEST VOLTAGE FOR ELECTRICAL EQPT.

0 Answers

For more Electrical Engineering Interview Questions Click Here