Answer / javad ahamad

both e/f relays are different. consider an alternator, its
neutral is earthed through a
resistance inorder to limit earth fault current .then we
cant protect the 100% winding from
differential e/f relay only.because if an e/f occurs at
very near to neutral point the driving
current to operate relay will be very small. there for it
cant be sensed by this method,
we can protect up to 80%(approximate value.depent upon
resistance)only.at this situation
we r providing a restrcted e/f relay to protect the
remaining winding ie 20%.this relay
have very low current setting.by the combination of these
two we can protect 100% winding.

what is the function of an auto reclosure relay in OHL?

1 Answers  

---

what is meant by neutral Ct of a transformer and how it connected in transformer

4 Answers  

---

Why the suply frequency in INDIA is 50HZ

5 Answers   HCL,

---

Why two phase welding machine is used instead of three phase welding machine.

0 Answers   Merck,

---

any body know about lighting arrestor. how to determine the height of lighting rod from top of bulding and how many area it cover.

1 Answers  

---

What happens to the synchronous generator when reverse power is given to it?

1 Answers  

---

what is the diff. btwn. electronic regulator and ordinary rheostat regulator for fans?

3 Answers  

---

WHAT IS M.P.C.B

3 Answers  

---

At no load the PF of an alternator -Zero -Zero Lagging -Zero leading -None of the above

2 Answers  

---

What is the Levels of High Voltage, Medium Voltage & Low Voltage?

1 Answers  

---

what is effect of leading power facter on the system and billing

0 Answers   TATA,

---

While starting a high capacity motor, it takes 6 times the full load current. Why it doesn't trip relay or CB's in that network?

4 Answers  

---