shekhar_dandya Posted September 23, 2005 Report Share Posted September 23, 2005 Hi All,I wanted to know that is neutral wire connected to earth at some point ?If not then how do we get shocked,since to get shocked,current must flow from live to neutral?-Shekhar Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 23, 2005 Report Share Posted September 23, 2005 Hi Shekhar,The neutral is connected to ground probably in the transformer down the street from your home.I think they ground it to provide a path to ground for lightning, and for any leakage current.If you worry about being shocked, then you should have Ground-Fault-Interrupters installed on receptacles located near grounded objects like in bathrooms and for outside. They disconnect the power when they detect a tiny current to ground. ;D Quote Link to comment Share on other sites More sharing options...
Raver2097 Posted September 23, 2005 Report Share Posted September 23, 2005 Hi Shekhar,As said by audioguru, the neutral is effictively connected to ground in the transformer. This is made to allow the differential interruptors to work when a leakage appears in the circuit. Quote Link to comment Share on other sites More sharing options...
shekhar_dandya Posted September 26, 2005 Author Report Share Posted September 26, 2005 But,if neutral is not connected to ground,and there is no special protection circuits around,is it that we never will get shocked when we hold a live wire? Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 26, 2005 Report Share Posted September 26, 2005 If your electrical wiring didn't have a ground, then it might spark all around your house during lightning storms, causing your house to catch on fire. Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted September 26, 2005 Report Share Posted September 26, 2005 I don't know about the US but here in the UK the neutral is connected to ground where the mains enters the building just before the consumer unit, the Quote Link to comment Share on other sites More sharing options...
ante Posted September 26, 2005 Report Share Posted September 26, 2005 This might explain a few things, or it might not! ;D [attachment deleted by admin] Quote Link to comment Share on other sites More sharing options...
shekhar_dandya Posted September 27, 2005 Author Report Share Posted September 27, 2005 I think my basic question remains unanswered as far as theory goes:"But,if neutral is not connected to ground,and there is no special protection circuits around,is it that we never will get shocked when we hold a live wire? " Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 27, 2005 Report Share Posted September 27, 2005 Yesterday my son touched a 120VAC live wire and felt a small shock even though he wasn't grounded (lucky for him!).I guess some current flowed through his capacitance to ground.He asked, "Why don't the birds get shocked when they perch on a high voltage wire?" I explained that they are small so have a very low capacitance to ground, and are stupid like him.Actually, it was the electrician who wired the breakers for my home who was stupid. They weren't marked and the breaker box is upside down. My son turned off nearly everything but not the correct one. :( Quote Link to comment Share on other sites More sharing options...
ante Posted September 27, 2005 Report Share Posted September 27, 2005 Why is it called “live” when it easily can cause the opposite? ;D Quote Link to comment Share on other sites More sharing options...
prateeksikka Posted September 29, 2005 Report Share Posted September 29, 2005 hi audioguru!i think your son must have touched ground. is it possible for the mid air to ionize at mere 120V and cause breakdown(fee movement of charges!) ?i dont think so.................... ;D Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 29, 2005 Report Share Posted September 29, 2005 I won't try it but I think a person's capacitance to ground passes enough current from a live mains wire to be felt as a mild shock. It is enough current to light an NE2 neon bulb in your hand. We use the extremely high mains frequency of 60Hz over here!Long ago, the mains frequency was only 25Hz. If you got a shock you vibrated so much that it knocked your teeth out. Transformers and motors were huge. ;D Quote Link to comment Share on other sites More sharing options...
prateeksikka Posted October 3, 2005 Report Share Posted October 3, 2005 Ive heard a few kilo volts is enough to knock u down even without ground.but if grounded gosh..60-70V will do the job.Air's ionization potential is a few thousand volts and it can only cause u a shock if air ionizes and circuit is completed. ;D Quote Link to comment Share on other sites More sharing options...
aakaash Posted October 3, 2005 Report Share Posted October 3, 2005 I think my basic question remains unanswered as far as theory goes:"But,if neutral is not connected to ground,and there is no special protection circuits around,is it that we never will get shocked when we hold a live wire? "HiShekhari joined this room today only and read it n felt ur basic qu is remained unanswered. Coz u forgot the basics of current flow. The nutral n grnd wire have nothing to do with shock. If u hold live (phase) wire in hand the current will flow thru ur body to ground and u r bound to get good shock ;D . Aakaash Quote Link to comment Share on other sites More sharing options...
ec_deepak Posted October 7, 2005 Report Share Posted October 7, 2005 HI SHEKAR, i think so that there is no any quite difference between the neutral and the earth wire, as we know that the earth wire is gronded , hope so yhe same at uor home power supply. Quote Link to comment Share on other sites More sharing options...
prateeksikka Posted October 7, 2005 Report Share Posted October 7, 2005 hi aakash!the topic has remained same nd we are now discussing the amount of voltage u need in case there is no direct connection between u and ground. Quote Link to comment Share on other sites More sharing options...
MP Posted October 8, 2005 Report Share Posted October 8, 2005 Shekhar,In most geographical regions, code requires the Neutral to be connected to ground in your service breaker box. If you have the opportunity to look inside, you will see that they are all connected by a buss bar and all of the grounds are connected to the same place. The wires in a receptacle are open loop and thus waiting for something to complete the circuit. If you touch the Hot wire, you can become a path to ground and this is how you can get zapped. The only way that a Neutral wire will give you a zap is if you are a better path to ground than the Neutral circuit where it connects to the buss in the service box. Yes, if you have a loose Neutral wire in the breaker panel, you could get zapped by touching this side of the circuit. This is not uncommon. One way to find such a faulty circuit is by measuring voltage from Neutral to Ground at the receptacle. If it is greater than zero, you have a loose wire or corrosion, or something causing a weak connection of one of the circuits to ground. In other words, if the wire where it is connected to the buss bar is not at ground potential due to looseness or corrosion or rust, etc, you might be a better ground potential than the connection in the service box.hope this helps you in your quest.MP Quote Link to comment Share on other sites More sharing options...
aakaash Posted October 8, 2005 Report Share Posted October 8, 2005 hi aakash!the topic has remained same nd we are now discussing the amount of voltage u need in case there is no direct connection between u and ground.HiPratikIn direct touch to ground also "amount of shock " is decided by many things like if ur hand is wet , the resistance of skin decreases n more current flows thru ur body n u get life-spoiling shock. This body resistance varies person to person. Some hav xcptnal high so they can easily handle live-wire!! But normally few milliAmps can damage u severly. So its not the voltage but body-resi to decide. So in case of open ckt (not touching grnd) along with body resi , wet or dryness of body , humidity of air , wetness of ground , etc r also imp along with high volt to make flow those killing few milliAmps thru ur body after breaking high resi of open air inbetween.AakaashIndia Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted October 8, 2005 Report Share Posted October 8, 2005 The frequency also plays a part, 50/60Hz will stop your heart but 100kHz will just make your hands warm (or bun you if there's enough power) as the nerves in your body can't resond to high frequencies. Quote Link to comment Share on other sites More sharing options...
prateeksikka Posted October 8, 2005 Report Share Posted October 8, 2005 hi alun!i guess it is again a debatable issue .some people 220 V dc as more dangerous than 50Hz 220 V ac because 50 Hz wave gives u 50 chances of survival in just 1 second.....how about that.About akash's point i have ultimately concluded that it is the power i.e energy dissipated into u in 1 second which makes u die and not just voltage or current.in short it is V*I. Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted October 8, 2005 Report Share Posted October 8, 2005 Oh sorry, I forgot to mention that DC is worse than AC because it causes your mussels to cease up, put simply the lower the frequency the worse it gets. Quote Link to comment Share on other sites More sharing options...
prateeksikka Posted October 8, 2005 Report Share Posted October 8, 2005 hi alun!also the skin effect also dominates at very high frequencies and does not damage the inner organs.(considering body to be perfect conductor)... ;D Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 8, 2005 Report Share Posted October 8, 2005 I disagree.Your guts conduct a lot better than your skin. Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted October 9, 2005 Report Share Posted October 9, 2005 Audioguru, you're supposed to be an expert and you don't even know about the skin affect ::) I drunk now andI still understand that electricity of a high frequency doesn't flow though the centre of conductors but passes thought the outside of skin. ;D Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 9, 2005 Report Share Posted October 9, 2005 I think that the skin effect occurs at radio frequencies beginning about 1mHz, in the AM broadcast band.I was up in an antenna mast in a tower with megawatts of microwaves there. I was given a microwave oven testing meter and was told that if it responded then to get the **** out of there as fast as I can. Those microwaves don't know about the skin effect because they cook you from the inside. Quote Link to comment Share on other sites More sharing options...
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