Answer / a.p.nanjappa

yes. what is the capacity of motor?
In your case , grid voltage is 33kv, Yn connected.Hence
power transformer has neutral connection brought
out.Neutral CT is installed to detect the ground faults.
secondary of 5MVA tranformer is 6.6kv,
This is Feeder bus voltage.6.6kv Feeder bus feeds Motor (
star connected). and Feeder bus is not interconnected to
another source. It is independent.This 6.6kv rotates at 30
lagging to primary3kv system.
Motor must be use inverse & instantaneous time
overcurrent and earth fault ( CDG61+cdg12) or equivalent
manufacturer protection
we use delt to star as weelas star 6.6motor.
No problems experienced.
In the othercase to change a 30MVA,33/6.35KV IS
REDESIGN/MANUFATURING. iT IS EXPENSIVE.No use at all and
advantage. You should change 6.6kv sw.gr also.

Why HT motor of 3.3 kw or 6.6 KV, one side foundation ( mostly non drive end ) keep insulated from ground ?

2 Answers  

---

In a 3 phase system a neutral exists so that any unbalanced currents can flow through it towards earth.... but a phase demands a particular current as per the load attached to it....then where does the extra current come from the goes in the neutral??....I mean in an unbalanced system a phase demands a current as per its load attached....then where does the unbalanced current come from??

1 Answers  

---

What will be the change in its efficiency and other parameters of a ONAN transformer if it changed to ONAF transformer ?

3 Answers   Tesla,

---

What is the working principle of VFD

3 Answers   HCL,

---

what will happen if i will done heart shape hole in transformer core?

1 Answers   Bhel, ONGC,

---

Draw the single line diagram of the power station?

0 Answers  

---

When color of silica gel will gets change from blue to pink from Top to bottom?

0 Answers  

---

What is the difference between SSR drive& AC drive?

1 Answers   ITC Infotech,

---

what is the reasons for blowing fuse

1 Answers  

---

How many types of circuit loads are there in a common electrical circuit?

0 Answers  

---

why transformer is giving some humming noise .....?

11 Answers   Electrotherm, JSW,

---

What is the Minimum winding resistance of motors ( small & big)? referance range

0 Answers   TATA,

---