In a 3-Pin Plug, one pin is larger than the rest. Why?

Replies

• 

  pikachu1994

  the reasons are (1) that it has to operate the safety shutters fitted to the corresponding socket outlet, enabling the line and neutral pins to enter the socket, and (2) it ensures that the appliance is always earthed before it is energised and de-energised before being unearthed.
• 

  Saandeep Sreerambatla

  Normal terms the big one is for earthing!
• 

  pikachu1994

  if it is wrong please correct me
• 

  sndgpr26

  pikachu1994

  the reasons are (1) that it has to operate the safety shutters fitted to the corresponding socket outlet, enabling the line and neutral pins to enter the socket, and (2) it ensures that the appliance is always earthed before it is energised and de-energised before being unearthed.

  these two reasons may not justify because it can be done by keeping the third plug of same size also.
• 

  [Prototype]

  Its just kept bigger to explicitly distinguish it as a Ground so you don't plug it incorrectly.
  
  
  (Sorry I am not very good in drawing & things, so bear with this)
  
  You see, you're supposed to plug-in A = GND, B = live/neutral, C= live/neutral. If both A, B & C are of same size, what's there to stop me from pluggin A = live/neutral, B=GND or any other way than it should be? You would say it idiotic to plug that way, but such mistakes do happen since humans are involved & sometimes, the curiosity bugs bite hard as well.😛
• 

  naveee

  why earthing is needded ?????👎
• 

  naveee

  sndgpr26

  these two reasons may not justify because it can be done by keeping the third plug of same size also.

  y earthing is need???
• 

  naveee

  can anyone explain me y earthing is need ????
• 

  [Prototype]

  naveee

  can anyone explain me y earthing is need ????

  Current always flows in the path having lowest resistance from higher potential to lower potential. Take a case where you've a device with a metallic body & a live getting shorted with it. Now, if there is no ground connected to the body of the device & you touch it, you know what's gonna happen. Here, you'll be the path having lowest resistance connected to the lower potential aka the earth.
• 

  naveee

  [Prototype]

  Current always flows in the path having lowest resistance from higher potential to lower potential. Take a case where you've a device with a metallic body & a live getting shorted with it. Now, if there is no ground connected to the body of the device & you touch it, you know what's gonna happen. Here, you'll be the path having lowest resistance connected to the lower potential aka the earth.

  this implies only to a device having metallic bodies..... ?????
• 

  Jeffrey Arulraj

  if you are not yet sure your body offers a resistance of about a mega ohm if there is an alternative path having lesser resistance then you are safe else i don't want to say
  
  a continuation of @[protype]'s post
• 

  Jeffrey Arulraj

  naveee

  this implies only to a device having metallic bodies..... ?????

  not so all devices have some resistance but if that is higher than your body you are at a greater risk
  
  in general that is the reason all devices have metal bodies
• 

  [Prototype]

  naveee

  this implies only to a device having metallic bodies..... ?????

  Not at all, but its highly expected in the devices having metallic body. You cannot estimate the number of ways you can get in contact with the live. A cut in a wire, a breakage in device exposing internal parts, handling with wet hands & the list never ends...
• 

  naveee

  another..... a two pin plug wire which has a cut in a wire.... if get in to the contact of tht wire will i be eltrocuted????
• 

  naveee

  [Prototype]

  Not at all, but its highly expected in the devices having metallic body. You cannot estimate the number of ways you can get in contact with the live. A cut in a wire, a breakage in device exposing internal parts, handling with wet hands & the list never ends...

  since a two pin plug wire which has a cut in a wire.... if get in to the contact of tht wire will i be eltrocuted???? ....becoz two pin wont hav a earth ???? conection ?
• 

  [Prototype]

  naveee

  since a two pin plug wire which has a cut in a wire.... if get in to the contact of tht wire will i be eltrocuted???? ....becoz two pin wont hav a earth ???? conection ?

  BINGO! Provided you didn't wear any shoes & touching the ground with bare foot, or not lying such a way that some of your bare body part is touching the wall.
• 

  naveee

  wat is the diff between transistor and radio ??????
• 

  [Prototype]

  naveee

  wat is the diff between transistor and radio ??????

  Prefer creating your own thread with doubts that are not related to the topic of this thread. You'll be served better that way & others will also find it easily if they have similar doubts.
• 

  sndgpr26

  naveee

  y earthing is need???

  when the two wires get shorted
  and suddenly when you touch it you yourself will be the low resistance path for current to flow
• 

  Jeffrey Arulraj

  [Prototype]

  BINGO! Provided you didn't wear any shoes & touching the ground with bare foot, or not lying such a way that some of your bare body part is touching the wall.

  this way of dying is not really cool for the pain and agony is too much better dont use shorted switches try to get them fixed and check the earth once in a while
• 

  priya ts

  for the high safety of human,the earthpin is larger than others
• 

  akshetty

  its safety & identify to earthing pin..
• 

  nirwan19

  K@RTHIK

  in a 3plug pin why one pin is designed larger than the rest,any reason for this!

  In 3 pin plug .....
  1> we have 1 live , neutral and earth.
  2> Bigger one is for earth as you said.
  3> Why bigger ?:-
  Ans:- because earth is used to bypass the access current , at the time of any accident . we choose it bigger because it will have less resistance comparatively, So at the time of any accident , then that current will choose the path having low resistance , as you may now .
• 

  naveee

  priya ts

  for the high safety of human,the earthpin is larger than others

  i thought it is for identification betwn phase nad neutral pin
• 

  Naman Agarwal

  earthing is done just to provide a path to leakage current if it is there iin the circuit...
• 

  Naman Agarwal

  3rd pin is larger because larger the area of cross section, lesser is the resistance and thats why leakage current will opt for this path to flow ...thats why 3rd pin is kept larger...
• 

  Jeffrey Arulraj

  naman2511

  3rd pin is larger because larger the area of cross section, lesser is the resistance and thats why leakage current will opt for this path to flow ...thats why 3rd pin is kept larger...

  True to the part pal