Answer Posted / jwalant yogi

First of all, REF protection is used for the case of
internal faults of the transfomer.Secondly, in REF, usually
when the current flows back form the neutral to the source,
there is much larger current change in the neutral current
as compared to the phase currents.And Differential
protection usually works senses the changes in the phase
currents which is not much larger, that's why differential
protection and REF protection are totally different from
each other.each of them is having different significance
and used for a particular application.

For refrigerators the motor current is raised beyond its rating on both conditions when the voltage of the system is more(say 270v) than the rated voltage(220v) as well as when the voltage of system is less(say 160v) than normal voltageof 220v, why explain?

1926

---

what would happen if reactive power (kvar)is increased (more)or decreased (less)? how much exact reactive power should be maintained? and what should be done for that

2217

---

what is the pre charge circuit,what will be work which function it will be use plz tell me

1867

---

Why using synchronising methed in DG's sets?

2147

---

how single phase preventer works ?

2488

---

why we can stote dc? why we cant store ac?

2039

---

what is the interrelation between voltage current torgue speed and magnetic flux in case of different types of electric motors

2029

---

suri transmission

4698

---

when measure the core loss of three phase distribution transformer or three phase reactor loss, one phase shown negative watt loss. why??

1934

---

What is different between Difnit time and instatous over current relay

2471

---

How to minimize the eddy current losses?

1105

---

Please give me a erda placement paper

1742

---

which IS or IEC is used for earthing,breakdown voltage of transformer oil, hv/pd testing and all type of electrical testing

2556

---

What is the maximum number of swithes that can be connected in series up to down stream point in an LV Distribution system?

1943

---

What is the ratio of Booster transformer?

2118

---