Answer / mahamuni raja

to determine the no.of earthing pits required is depends
uponn the area required to dissipate the fault courrent to
the area of pipe electrode.
To protect 35M building , 1no. of lightning arrestor is
sufficient however better to provide two nos.of down
conductors hence to protect the building if any one
conductor fails.

Answer / jagjeet

The LE installed on the Top of 35 mtrs high building covers
the redial distance of 35 mtrs across the LE on ground
level so the no. of LE not only depend on Height of the
building but the others dimensions of the buildings.

Answer / william lobo

The number of earthing pits depends on the soil resistance.
We may require earth resistance of 1ohm or 3 ohms at the
most. To get this we will have to install at least 2 pits
and as per parallel formula i.e. 1/r1+1/r2+1/r3= 1/R. We
have to keep on increasing the number of earth pits till we
get the required value for R=1 or 3 as per requirement.

Answer / anand

it is depends on what extent you need the safety level.

Answer / ramasubramanian.ganesan

Normally the area which is covered by a lighting arrester
calculated on the basis of PYTHAGAROUS statement.

In a right angled triangle, the sum of sqr.root of the
adjacent and opposite sides is equal to the sqr root of the
third side.

In the question asked the height is 35 meters. based on the
above we have to calculate the required datas.

What are the voltages at which electrical energy is transmitted

7 Answers   KSEB,

---

wich types of current?

2 Answers  

---

we all know voltage is a force(emf), and the force always devides if 2 or more than2 loads are there but why does the voltage remains same is parallel, it must devide na ???

0 Answers   NTPC,

---

what is cutoff voltage?

3 Answers  

---

How do you calculate the actual power consumption of an inductive load appliance. Say, a deep freezer of 200watts

0 Answers  

---

---

for a machine R=130 KVA Y=132 KVA B=144 KVA Then what will be the total kva

3 Answers   ABB,

---

Where all & Why resistance grounding is required?

1 Answers  

---

can we use 400w coke instead of 250w choke in 250w fittings

2 Answers  

---

why are the maintaine power factor and how can this control and this is how work.

0 Answers   Mukand,

---

what do you mean by earth fault in transformer?

2 Answers   L&T, UPL,

---

why we used stone chips under the transformer area..

2 Answers   SSC,

---

1.4 What is meant by CT knee point voltage and how would you determine it

0 Answers  

---