Answer / sudesh

according to IEE regulations recommended voltage drop is 3%.
voltage drop=(400x3)/100
=12V
if we select 35sqmm pvc/xlpe/cu cable, it can carry 158A max.current.
so now we should consider about voltage drop of cable.
true voltage drop=volt.drop for cable*Current*Distance
=1.15mV/A/m * 125A * 50m
=7.18V
7.18 < 12
so 35sqmm cable would be best to carry 125A current.

What will be the output voltage of a transformer if it is primarily energized from a square wave voltage source?

0 Answers   HPCL,

---

Is it recommended to apply H.pot test for new cables segments after terminations or joints, however, this cable has been tested before at the manufactor by the vendor ? or only we can apply megger tests ?

1 Answers   Centroid,

---

Difference between single phase and three phase?

1 Answers  

---

IN 3 phase induction motor where we give i/p supply & how its working ?

2 Answers  

---

Fot testing new star-delta 132 kw motor in electrical worshop.we should check in star or delta connection as we do not have higher capacity cable in worshop?

4 Answers   Adani,

---

what is breaking capacity

1 Answers  

---

What does substation operator do in substation?

2 Answers   ABB,

---

how does a tube light starter works?

2 Answers  

---

Is 3C x 2.5 Sqmm Cable can withstand 40Amp Starting current? If Yes then specify your ans.

2 Answers   NTPC,

---

why the transformer has no starter

2 Answers   NTPC,

---

1)How much current can a 3-1/2 core 100 mm wire carry? 2)What are the special cables required for explosion proof wiring? 3)In case you do not have coal and salt for earthing, how can you achieve good temporary earthing? 4)One horse power single phase motor is more likely to get hot than a one horse power 3 phase motor. Is it true or false, if true why? 5)What are the different types of soft starters for large motors?please explain?

0 Answers   TATA,

---

WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying to a lighting & power socket DB.Settings in the MCCB is Ir = 63 * 1 , Isd = 8 times of Ir , tsd = 0.5 sec( I2 t off). Sometimes this MCCB is tripping .But no trip in DB MCB. Can anybody tell me reason ? From where i can know about the MCCB settings?

5 Answers  

---