Answer / mahesh-lanco

The Main Functuion of the Insturments Transformers(Current
Transformer &VOLtage Transformers) is to Standartise the
secondary to less value. As the Relays and Circuit breakers
are designed at Very Low Values(DC).If the fault curent or
voltage is very high there is no meters manufactured for
the measurment of such high volatgaes/currents the
Secondaries of CT &PT are standartized to 5Amp and 100V
respectively

Answer / abhik raj

it is standard that CT sec should be 1 or 5 amp based on
partys demand.becz relay/meter are designed for the
same.otherwise it is difficult for both manufacturer/user.

Please let me if star point(Nutral) of Delta/ Strar transformer, in 4wire (TPN+E) is tobe gruonded seperatly,inaddition to LV Panel earthing????

1 Answers  

---

could an induction motor be used for regenerative braking in electric-train control? in this type of application would some scheme have to be devised to obtain low synchronous speeds while braking? would induction-motor drive, therefore, be suitable for passenger service?

0 Answers  

---

Differences between 415v ac and 440v ac

3 Answers  

---

How to decide CT & PT ratings for a given transmission line carrying some rated voltage?

0 Answers  

---

if sf6 gas low in gis what will happen

0 Answers  

---

HI SIR, AM PREPARING FOR RRB FOR SECTION ENGINEER POST. PLZ SEND ME THE PREVIOUS QUESTION PAPERS AND HELP ME. I HAVE NO ENOUGH TIME MY EXAM DATE IS 22ND JUNE.... MY EMAIL ID IS nalla.amarnath@gmail.com

0 Answers  

---

I need to calculate the Battery bank back up for below configuration:- UPS - 120 KVA Battery Bank - 200Ah Volt of each cell - 12 V Total No of cell - 34 No's Can you please help me to get the battery back up time for above configuration...? along with formula

1 Answers   Wipro,

---

where is the primary of CT??

3 Answers  

---

why we use 25 kv in railway .not 11kv, or 33 kv

2 Answers   ISRO,

---

what is the difference between relay and a contactor.

5 Answers   Siemens,

---

How transformer neutralshould earthed ? Transformer neutral connected to earth mat in substations, right or wrong ?

4 Answers  

---

Capacitor panel CT is normally fixed on Y phase of the main panel.why???

3 Answers  

---