Answer / manisand1

CT resistance = 1.8ohm,
Lead resistance = 4.0 ohm,
Starting current = 195*5/200 = 4.875 Amp
Starting voltage = 4.87(1.8+4)= 28.275 = 28.3 volts
This is to be set to 30Volt,

But please remember that knee voltage should be 60 volt
minimum.

For anymore clarification you can mail me to :-
manisand1@hotmail.com

Answer / puneet prashar

Knee Voltage=2X Earth Fault current(RCT + RW)/CT
Trasformation ratio

Where
RCT= CT impedeance as per manufacture1.02
RW = Wire resistance as per manufactre
say.oo32/metre then RW= 2X 200mtr X .0032

CT transformation ratio= 4000/1=4000
4000/5=800

VKnee= 2X58000(1.02+1.28)/4000 or 800 depending upon ct used

Vknee= 66.7v

Vknee> relay stability Voltage

Relay stability voltage formula will be given by relay
manufacturer as every relar manufacturer has their own formulas

what would u consider to be the basic purchase order information you would need to proceed with a cable inspection assignment?

0 Answers  

---

Anybody know how schematic diagram for reverse power relay? RPR for generator protection

0 Answers  

---

can we keep open the secondary of current transformer?

1 Answers   Jyona Power,

---

what is the resistance value of earthing pit and why they are connected?

6 Answers  

---

how harmonics are generated due to nonlinear load & how harmonic filters work?

1 Answers  

---

---

what is the range of thermal overload and over current. Answer should be in percentage of current.

0 Answers   RMSI,

---

I have 4 DG set with 1500KVA rating. system breakers are 11KV & alternator are 415 Volts. Between alternator & breaker one stepup transformer used. i want to Know what is max. resistance for body earthing & 415 & 11KV V Neuteal earthing. my fault current is 14 times for 2 sec.

0 Answers   Jindal,

---

what is the difference single phase and 3phase starter

1 Answers  

---

How much CTs are required to measure th curent in DOL starting of motor?PLs explain.

1 Answers  

---

What safety followup during kWh meter isolation

0 Answers  

---

1.Is there any difference between terminologies,HT-HV &LT- LV? 2.What is the highest transmission voltage level in india?

5 Answers  

---

why voltage coil in wattmeter called as pressure coil why the pressure term is used in wattmeter?

1 Answers   NPCIL,

---