2007-01-03 03:47:26 · 12 answers · asked by CPJ 1 in Science & Mathematics ➔ Engineering
To earth it, to prevent electrocution.
2007-01-03 03:50:57 · answer #1 · answered by Carrie 3 · 0⤊ 0⤋
The electrical supply to a typical house has two phases coming into your fuse panel. These are called hot wires. These hot wires distribute electricity to the appliances in your home and then return back to the fuse panel by a "common" wire. This is the normal or design current path for any electrical appliance. A third wire is added called a ground wire to provide another path back to the fuse panel. This wire is added in case a "ground fault" or alternate path to ground develops in the circuit. This can happen if the hot wire in the appliance should come into contact with some metal part of the appliance. When this happens, if a person touches a metal part on that appliance and is at or close to electrical ground potential, then electricity can flow through the metal part into their body and to ground resulting in an electrical shock.
A ground wire is added and is normally connected to a metal portion of the appliance. That way if there is leakage from the hot lead to the appliance the alternate ground is a lower resistance path to ground than is your body. So the electricity will preferentially flow back to ground through this alternate path instead of your body.
This third prong on plugs is important. It is there to protect you, so don't even think about cutting it off. Some people do that because they live in older homes that don't have 3 prong receptacles installed. If this is the case in your home, you should think about upgrading the outlets.
There is one special case of wiring in your home that is different, and that is on your drier connection. These generally have a large plug with three connectors. In this case two of the plugs are hot wires. They are each connected to a different phase coming into your house. The third plug goes back to ground.
2007-01-03 04:53:12 · answer #2 · answered by richard Alvarado 4 · 0⤊ 0⤋
Richard Alvarado
"A ground wire is added and is normally connected to a metal portion of the appliance. That way if there is leakage from the hot lead to the appliance the alternate ground is a lower resistance path to ground than is your body. So the electricity will preferentially flow back to ground through this alternate path instead of your body."
AND
this ground wire is protected by Earth Leakage Circuit Breaker which will trip supply circuit in case of a ground fault and the electrician can correct the faulty situation and will switch on the breaker back in service for you.
2007-01-03 05:08:57 · answer #3 · answered by Sheen 4 · 0⤊ 0⤋
voltage is relative, even a negative charge is still a charge. The only assumed zero charge is the earth (and it's also the same all over the world). Therefore, the earth ground provides the best protection from any form of charge. Electricians use an earth ground to shield people by attaching it to the exterior of the case. This also prevents things such as electrical shocks from penetrating the case and damaging the interior electronics. In effect, it's a barrier to all charges that is the ultimate in zero charge.
2007-01-03 04:07:05 · answer #4 · answered by armus 2 · 0⤊ 0⤋
SAFETY. I repeat.....SAFETY.
The appliance is directly connected to this prong - if there is a malfunction inside the appliance that causes the live (hot) wire to contact the housing, the current will find a low resistance path to ground and trip the circuit breaker or blow the fuse - much better than having you become this path to ground!
2007-01-03 03:54:28 · answer #5 · answered by LeAnne 7 · 2⤊ 0⤋
Its an earth, in case there is a fault with the appliance causing electricity to contact the outer casing, which could potentially kill you, with an earth in place this electricity will be channeled through that third plug and into a conductor (usually the central heating pipes) and eventually it will flow into the ground removing the risk of electrocution.
2007-01-03 03:51:10 · answer #6 · answered by Keiko 2 · 0⤊ 0⤋
It blows a fuse if there's a fault in an appliance. 2 prong plugs are used in double insulated appliances.
2007-01-03 04:03:56 · answer #7 · answered by Crash 7 · 0⤊ 0⤋
I am sorry if this sounds sarcastic but you answered your question, within your question ! "purpose of the grounding pin"
Not that it works, because it depends if your House has up to date wiring, because some old homes never were grounded, and you can tell this by the lack of outlets not having the 3 " holes" that you put your plug into or not having a GFI in the bathroom & kitchen !
2007-01-03 04:00:00 · answer #8 · answered by madman 2 · 0⤊ 0⤋
To protect the appliance from grounding out and/or having someone receive a shock from the unit.
2007-01-03 04:05:30 · answer #9 · answered by Richard V 1 · 0⤊ 0⤋
It takes the excess electrons into the earth. Thes may come from static or otherwise in the appliance.
2007-01-03 03:52:10 · answer #10 · answered by science teacher 7 · 0⤊ 0⤋
If the power gets shorted to the case, this shorts it to ground, opening the circuit breaker, so you don't get zapped.
2007-01-03 04:05:51 · answer #11 · answered by Anonymous · 0⤊ 0⤋