Answer / jkgjk

When we insert 3-pin plug in the socket, first longer and
thiker pin touch the plug, which is connected through earth.
This is for human protection from earth fault.

Answer / manju

thicker pin is connected through earth,as v know that as the area of connection (conductor)increses the resistance decrease
R=$L/A. incase of earth fault, current easily flow to earth through thicker earth pin. tis will protect human from shock.

Answer / rajesh tanwar

The earth pin in the socket is longer so that the phase and
nuetral get disconnected first and earth is disconnected
very last to gave a sufficient protection.

Answer / praful nandankar

earth pin is used in socket to prevent the person from
shock.earth pin is thickeras u know that the thickness is
indirectly proportional to resistance.Hence excessive
current flows through the earth pin during abnormal
conditions.

Answer / shivendra

we know that R=p(L/A).So as the area of cross section increases the resistance decreases AND the current follows the minimum resistance path.So in case of fault current excessive current will flow via earth pin thereby saving the human from shock.

Any one can explain if there is any harm from humming noise heard from air circuit breaker : we have 415 switch board having two incomers from transformers 3.3KV/415V , when bus coupler closed, and open one ACB incomer to work in one of the transformers, the current started hunting around 50 Amps, and heard humming noise from the air circuit breaker, although the load current was only 1200 amps while the ACB capacity is 2500 Amps, and the transformer 1600 KVA. The same didn't happen when taken the other transformer offline. Why this humming noise and current fluctuation? is there any implication or danger, bearing in mind that we just returned everything back to normal and stopped the maintenance of the transformer. Shall we go ahead and ignore this noise?

6 Answers  

---

what is Over current, earth fault (O/C+E/F) ?

2 Answers  

---

We have laid the single core Armoured cable 7 nos ( 2 each phase & 1 neutral ) to cater our electrical load . the issue is though we have Glanded the cable both the end also givan the earthing to the panel both the end we are facing a heavy sparking at the gland side. what could be the reason.

12 Answers  

---

Safety of on line ups

0 Answers   Bhushan Power Steel, GE,

---

Do u know any one? how to find out in motor rated amps? formula?

0 Answers   Banking, ET,

---

---

We have 110Vac ,10A ac supply which is converted into 110VDC & How much DC current? which factor is reqired for dc current calulation?

1 Answers   Suzlon,

---

can induction motor run over the rated speed ?

12 Answers   ACC,

---

'documenˁ

0 Answers  

---

PLZ EXPLIN ABOUT CLASS PS CLASS CT .WHY THEY R DESINED AND FOR WHAT PURPOSE?WHY OTHER CT CANT BE USED AS PS CLASS CT? EXPLAIN IN SIMPLE LAUNGAGE IF POSSIBLE PLZ GIVE CIRCIT DIAGRAM?EMAIL-RAJ_SINGH_0376@SIFY.COM

0 Answers   ABB,

---

give single line diagram of D.G distribution form alternator to main L.T panel?

0 Answers  

---

What is diversity factor and how to calculate it

2 Answers   Al Faraa, Amul, Pentagon, Sobha Developers,

---

What is the starting current of a DC Motor?

2 Answers  

---