Answer / guest

Stepdown transformer(HT/LT) generaly used for distribution purpose so secondary side star is necessary and to increase voltage ratio primary side delta is necessary ie. in delta we get line voltage which is 1.732 time of phase voltage (star voltag) therefore less turn required in secondary side.

Answer / siddhartha agrawal

Generally HT side there is only three phase available while
LT side we require neutral. So we connect LT side Star
connection to use phase to phase voltage (415 volt) and
phase to neutral voltage- single phase load (240-220volt).

Generally HT side there is only 3 wire to reduce the cost of
transmission wire cost.

Answer / ap

we use delta connection in primary side (HT side) because if any fault current occurs it circulates in primary only and is not transmitted to secondary. Thus secondary is free of fault current.

Answer / bikki

In HT transformer, the primary side has less voltage stress since it is a step up transformer. But the voltage on secondary side will be high and hence the stress will be also high.As a result, the winding insulation requirement will cost a lot if the connection was Delta on secondary side;because in delta phase voltage=line voltage.
But if the secondary connection is star, then phase voltage will be Line voltage/(sqrt(3) which means the winding has to withstand less voltage stress and hence less insulation is required.Hence lesser cost.

Comparative difference between 33Kv & 66KV for transmitting the load of 7 MW at a distance of 34 Km.

6 Answers   NHPC,

---

How line capacitance & line inductance varies with increase in height tower.

0 Answers  

---

why rotor resistance starter is not suitable for squrielcage induction motor?why it is suitable for slipring induction motor?

5 Answers  

---

Can anyone provide with a SLD for HT panel installation for a 33KV line and distribution end has three 1.5MV transformers. Is it suitable to use OCB or VCB and also provide me the suitable rating and its connection diagram.

0 Answers   TATA,

---

Usually in the L & T make MCC feeders' power circuit,we have BMR after the MAIN CONTACTOR.,can we interchange their position, keeping the control logic same???

0 Answers  

---

Is neutral transformer can be called as control transformer?

0 Answers  

---

What is the difference between earth and neutral

4 Answers   ABB, Tamboli Engineers,

---

How Load Factor, Demand Factor, Diversity Factor etc best applied in designing an electrical circuit? Is it allowed to consider these factors in each and every panel in an electrical distribution system? Can any body suggest a good book for reference?

0 Answers   Oberoi,

---

why no load voltage is greater than full load voltage?

1 Answers  

---

How to calculate Number of Earthing Pits....???

0 Answers  

---

What is the electrical difference between Earthing Switch (ES) and Maintenance Earthing Switch (MES)?

1 Answers  

---

Dear Friends, Need your help for connecting APFC panel, Quotation : I have 2 No’s 1000 KVA Transformers, both transformers are having separate APFC panels, ( Tr-1,400KVAR, TR-2,450 KVAR) Now I want to stop One transformer, present load is 650Amps, Max, So One transformer is enough, I have switched OFF TR-1, but PF is not maintaining properly, its 0.5, So now I want to connect TR-2 APFC also in TR-1 Loads, Can any one answer for my Quotation with drawing, how to connect TR-2 APFC panel in TR-1 Loads,

4 Answers   L&T,

---