Answer / ranjith

It detects the faults of winding in neutral grounding side

Answer / k.prakashchandra

REF is restricted earth fault relay, for internal earth fault of Tr . SBEF is standby earth fault relay or backup for both internal and outside earth faults . The CTs of both are connected to neutral of Tr. Discriminative setting is required

Answer / suresh

Ref is restricted earth fault, The relay was acted  for winding to winding shorted with ground.

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  

---

how braking & making capacity of circuit breaker is calculated?

0 Answers  

---

why there is 1 phase and 3 phase but not 2 phase and 4 phase?

3 Answers  

---

What is the effect of electric motor stuck in star configuration,

0 Answers  

---

how many frequent start/stop operation possible in case of HT MOTORS.

5 Answers   DVC, Steel Plant,

---

---

What is the correct procedure to shutdown VCB in 11kv substation.safety and work procedure

3 Answers   EGA,

---

define bilateral network and unilateral network? give an example.

3 Answers   ABB,

---

why dimmerstate always connected in star connection? what will happen if it connected in delta?

0 Answers  

---

why we are not giving the zone 1 trip command to the master trip relay

0 Answers  

---

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?

0 Answers  

---

Determine the BTU size of an aircon for 20 sq metre room

0 Answers  

---

how can we judge the percentage of load on the basis of temperature differences readings between WTI and OTI in a transformer

1 Answers   Toshiba,

---