Answer / raghavendran

I am not sure but,this could be the reason, the Electrical
field intensity producing corona on contaminated areas,
water droplets, icicles, corona rings, ... This corona
activity then contributes nitric acid to form a chemical
soup to change the bonding cements and to create carbon
tracks, along with ozone and ultraviolet light to change the
properties of NCI insulator coverings. Other detrimental
effects include water on the surface or sub-surface freezing
and expanding when thawing, as a liquid penetrating into a
material and then a sudden temperature change causes change
of state to a gas and rapid expansion causing fracture or
rupture of the material.

Answer / aboli

I think impure water or ice being good conductor of
electricity,due to ice coating the insulator may get
directly short ckted.this could be called as puncturing of
insulator by ice coating.

define transient state &steady state

1 Answers  

---

What are types of losses in the Transmisson Lines ?

4 Answers   GE,

---

what is the difference between OD and VL

1 Answers   Bescom,

---

What is the importance of earthing?

0 Answers  

---

why the desirable efficiency for a motor is 60%, but in case of transformer, it is above 90%?

1 Answers  

---

If a fan get trip and run in reverse direction due to system flow. Now in this condition during starting how can a VFD bring this negative speed to zero and later run in forward direction?

2 Answers   Aditya Birla, Siemens,

---

what is the difference between megger and earth resister ??

0 Answers   HMPL,

---

Can someone help me in the Below Quest on Earthing 1.Types of Earthing and Recommended for what use 2.What is the Pit value /Panel N -E value should be or within limit for RP and UPS .

1 Answers  

---

Why dc voltage used to excite alternator field in stead of ac?

4 Answers  

---

In star delta Schematic can we connect OLR in delta circuit

2 Answers   ABB, Lanco,

---

i am confused about generator. i have generator of 380 KVA that is 304 KW by that formula KW=KVA*0.8... then by this formula I=KW/V*1.732*0.8 the amperes are 528.673. so that is the load which i put on one phase of generator or this is total 3 phase load on Generator.......

3 Answers   Haliburton,

---

what is the difference in between short time and continuous rating?

1 Answers  

---