Answer / loboreliance2003

The DC voltage rating for high voltage insulation does not
take into account RF coupling of high voltage AC Signals
through the insulation to grounded objects. It is found
that high voltage wire insulation must be de-rated by
approx. a factor of four for the high voltage frequency
levels used. For instance, to run a 10KV triangle wave at
1KHZ requires insulation on the test cables with a DC
rating of at least 40KV.

what is the thumb rule for determination resistance of resistor?

0 Answers   Siemens,

---

Do any one know exacatly when the results for NHPC held on 8th march 09 for engineering trainees will be released ?. if so please post it, i'm eager to know it.

0 Answers   NHPC,

---

what are the industrail measures to over ferranti effect? how would the ferranti effect the power system if those remedial mearsure arent taken? how often does this effect occurs in real power system?

0 Answers  

---

Pls explain about vfd control?Where it is used, Give some example?

3 Answers   Siemens,

---

If i switch on a transformer but with no load connected to the secondary path.Is the transformer will burn?

5 Answers  

---

---

In a synchronous motor armature current flows due to revolving flux which in turn rotates the load,but in no load condition armature current is zero hence thr is no revolving flux then how motor rotates?

9 Answers  

---

How can we design a HVAC Plant room which includes AHU,FCU,Chillers,Cooling towers, Pumps etc & how will they work? any Drawing if possible?

0 Answers   TCS,

---

what is distribution board and panel board

3 Answers  

---

Three set (each phase contain 2 cable of 400 mmsq CU XLPE AWA) of single core cables are connected to 11 KV motor of 14 MW & the switch gear supplay is taken from 11kv feeder & this supplay taken from 275 KV substation. Problem is one pair cable(L3- 2 cable ) getting very hot & gland melted and damaged in switch gear side. the other two cable haven't any more hot(ambient temp only & L3 haveing 95- 100 Degree C. The same problem happened in 275 KV substation switch gear side also where the supply taken for 11 kv switch gear. But here L2 phese cable had problem. Why it is happening like this?. The cable having temperature different at different location from gland side inthe case of 11KV feeder of 275 kv substation. why ?

2 Answers  

---

what is means of CLASS in current transformer name plate?

3 Answers  

---

How will you determine the rating of a motor for continuous duty variable load motor applications?

1 Answers  

---

why should a transformer be never connected to dc supply

5 Answers  

---