Answer / eduardo

In a delta connection you don´t have any access to the "mid
point" or if you prefer to the "neutral".
In a star connection you will have a four(th) terminal, that
you can connect to earth or use it as neutral conductor.
For example if you have a three phase power line at 15 kV,
and want 400 V and 230 V you can connect the primary in
delta (you don´t need the extra connection) and the
secondary at star. (delta- star)
Now you will have 400 V between any 2 phases and 230 V
between one phase and the star point of the transformer.

If you connect the secondary in delta you will not have 230
V, because you don´t have the 4th terminal. (delta-delta)

Please note that in star one winding of the transformer will
have 5,8 kV (10000V / sqrt(3)). In delta connection you will
have in one winding 10 kV. So verify the tension and the
connetction type of the transformer. (both primary and
secondary).

Answer / shahbaz shaikh

in delta-delta transformer primary side and secondary side of transformer are connected in delta fashion i,e R-Y-B are connected in triangle fashion these are generally prefer for the transmission system and here no neutral point is present and for the distribution system we use the delta star because our home appliances are work at 230v but in 3 phase we have 440v so to get the 230v we use delta primary and star secondary so by using one of phase and neutral point of star we can get the 230v.

Answer / atta

Eduardo IS ABSOLUTELY RIGHT ,

will we have to design the UPS differently for both i.e. if we want to connect the two batteries in parallel and/or we want to connect the two batteries in series ?

4 Answers  

---

What is the technical reason for adopting color coding of three phase system as RYB.

11 Answers   ABB, ERDA,

---

Dear Respected sir how to test ABB REX521 protection relay by relay tester.

0 Answers  

---

Approach of a cooling tower is the difference between temperatures of what factors?

0 Answers   Blue Star,

---

What happen if transformer neutral path get removed ?

1 Answers  

---

What happen when change order of CT in GIS feeder?

0 Answers  

---

what are the various types of towers used in transmission line

12 Answers   Power Grid, UltraTech,

---

I have raw material for making Compact-Choke for flourscent lamp of 40 Watts. We are suppose to get 0.4 amps output at end. but we are getting 0.42 or 0.44 amps and above. We have done many testings in different but nothing worked out. Please suggest me how to get the correct output. We are using 1. core winding of 700 windings of aluminium 2. E-shape iron fillings and I-shape iron fillings to surround the winding.

6 Answers  

---

What it is the diff btw Package & PEC AC's????

2 Answers   Emerson,

---

How to calculate Earth busbar size & what is the procedure we make for determine that?

1 Answers  

---

What is DTR erection?

0 Answers  

---

HOW DOES ONE SELECT A TRANSFORMER PHASOR GROUP IE, WHETHER A STAR-DELTA TR OR A STAR-STAR OR A DELTA-DELTA, ETC. TRANSFORMER IS MORE SUITABLE FOR A PARTICULAR KIND OF LOAD OR WORKING CONDITION???

3 Answers   KPTCL,

---