Answer / santosh kawade

Rotar earth fault protection for generator (hydro or
thermal same scheme):

Rotar earth fault protection contains two stages 1st stage
earth fault protection and 2nd stage earth fault
protection.

As per scheme in normal running condition rotar core is
connected to rotar winding through a resistance bridge, as
soon as 1st stage rotar earth fault occur it gives alarm.

Then for 2nd stage rotar core is connected to ground
through a bridge and when 2nd stage rotar earth fault occur
it gives trip command to generator.

(Rotar connection to ground/winding is through a slip-ring
and brush system connected at one end of rotar.)

Santosh Kawade
9224 69 3116

Answer / siva

dc field flashing:to build up a voltage in a generator
residual flux is necessary. it is from the property of
retentivity of magnet. if it is absent we have to provide
the flux by a low voltage battery.this phenomena of
providing field flux(residual flux)by an external battery is
field flashing especially in dc shunt generator

cable selection formulas for electrical load.

1 Answers   Bhel,

---

what is high and low cut off voltage of BB and DG at SPS????????

0 Answers  

---

1- What is the Polarization Index number be good for 15KV 3c#500MCM electrical cable? 2- Can I use the IEEE Std 43-2000 to perfom the PI test? Thanks

0 Answers  

---

Why you want to join non technical field when you are an engineer?

0 Answers  

---

A 3 phase motor operating off 415V system is developing 20Kw at an efficiency of 0.77 and power factor of 0.73. determine:- a)the line current. b)the phase current if winding are delta connected. c)the phase voltage if winding are star connected.

1 Answers  

---

why does connected a indutor with mnsformeretering core of current transformer ?

0 Answers  

---

what is the affect of earth's magnetic field on the frequency used in aircraft???

0 Answers  

---

3phase 4 wire system is more reliable or 3 phase 3 wire systems?

4 Answers  

---

What is mean CT Saturation? How to calculate?

3 Answers   NetGroup, Tyco,

---

How to calculate the size of earth cable to earth the neutral of UPS ?

0 Answers   N Johnson,

---

What are various impedence in any machine

2 Answers   Engineers India Limited, NTPC,

---

what is differents between static stablizer and servo stablizer

3 Answers  

---