Neutral is a circuit conductor that normally carries current back to the source, and is connected to ground (earth) at the main electrical panel. Since the neutral wire is a potential between all three phases, each phase along with the neutral wire can form an independent circuit e.g your house, hence live and neutral. What happens if neutral wire touches a earth wire. if you put the live wire in the neutral terminal, the live wire in the earth terminal, the earth wire in he live terminal, the earth wire in the neutral terminal, the neutral wire in the live terminal, the neutral wire in the earth terminal and if you forget to put in just the earth wire. Click to see full answer. If you swap the two, then you have normal circuit current flowing on the ground wire and potential ground fault current flowing on the neutral wire. If you ALSO touched anything that was connected ⦠As long as there is a turning coil of wire on your appliance in that particular circuit, the Neutral wire will not be safe to touch unless there is an intimate relationship with the ground. But as ground and neutral are connected there, the harmful current may return through the extra earth-neutral connection and through the neutral wire. The answer is: In a WYE 4 wire system the neutral, in theory, carries only the difference of current flow between the 3 phase conductors. Nothing would happen if the two hot wires were from the *same* 120 vac feed line. Normal circuit currents flow only in the neutral, and the protective earth conductor bonds all equipment cases to earth to intercept any leakage current due to insulation failure. Neutral Wire. Neutral wires carry currents back to power source to better control and regulate voltage. Ben Ben. The live wire touches the earth wire. Its overall purpose is to serve as a path to return energy. If there is any difference (like when some of the current flows through the ground wire) then it cuts the circuit. Not every stream we consume can be monitored, as part of the return flow flows directly to Mother Earth without passing through the energy meter. This! “Whenever you have an auxiliary panel the neutral and ground should not be tied together because the ground wire becomes a parallel path for current with the neutral wire (any current going through the neutral wire will be shared with the ground wire because they have the same connections at both ends).”. If it is a single phase system then the total current passes to ground. Google serves cookies to analyze traffic to this site and for serving personalized ads. in a balanced 3-phase system there is no any current in the neutral wire,but if the system is unbalance then neutral will work as a returning path of un-balance current. Remember that voltage is relative. Just to add one more safety item about hot/neutral in the US. â This will create a short circuit as a large current which exceeds the fuse rating will from the live (240 V) to the neutral wire (0V) as that path has very low resistance. It causes unbalanced current flow in a three phase system. A common wire is a more general term and simply refers to the 0 Volt wire of a circuit, either electrical or electronic. Does Southwest Airlines fly to Ontario California? The purpose of grounding the metal parts to the earth is to protect persons and property from fires by limiting voltage on the metal parts from lightning [250.4(A)(2)]. If you touched it then you would at least get a buzz. Up to 5 wires can be used in a three phase system, with 3 live wires, 1 neutral and 1 ground (earth). There shouldn't be any any risk of electrocution in the enclosure since no-one should have the cover off without isolating the mains beforehand. In a plug, the live wire (brown) and the neutral wire (blue) are the two wires that form the complete circuit with a household appliance. regards malcolm. Either on its own, no immediate hazard. And the second effect is that our energy meter shows less readings (unethical hack). It can't do this if it is disconnected. While continental marinas are changing to this system, there is still no guarantee that the live and neutral connectors have not been reversed and many still use their national plugs. The fuse will blow. Non-linear loads cause harmonics , some of which will add up on the neutral. Not for many appliances, but for some that are sensitive it could cause problems. When I take off the face plate yes indeed, the socket has been wired correctly it seem (ie live wire to live terminal and neutral wire to neutral terminal) but both terminals are the opposite that anyone would expect (ie live terminal bottom left of the socket as you look at it)! According to the NEC, metal parts of service equipment shall be grounded to the earth. First, it can be dangerous if we come into contact with a defective device. Because of this reduction in resistance, the current flow will increase. Earthing Without the earth wire, if a fault occurs and the live wire becomes loose, there is a danger that it will touch the case. What is the difference between a resistor and a transistor. Add a comment | 1 Answer Active Oldest Votes. The next person who uses the appliance could get electrocuted. What are the differences between the somatic and autonomic nervous systems? A 4-wire system is common for groups of houses or small businesses. Live/neutral swap plus neutral earth swap = live case. In such cases, the current finds the shortest path to the discharge potential when we connect the neutral conductor to the ground. The live wire touches the earth wire. Understanding Electrical Wiring. It will get you someday. In The Philippines we usually connect the Neutral wire to the ground rod, purposely to make it zero volts wire or the green wire serve as ground should be connected to the appliance. , Now there are 2 effects of this work. If these connections are backward, the polarity is wrong. The neutral should never be connected to a ground except at the point at the service where the neutral is initially grounded (At Distribution Transformer). This is not always the case though. Since the neutral conductor has little potential, the current flow is minimal when we connect the earth to the neutral conductor. Standard wiring in the United States is done with plastic-sheathed ⦠Similarly, can I connect neutral wire to ground? If the ground is wired to the neutral, the ground of the applicance will also be live. regards Sparx. I need exaples of bad plug wiring and what happens e.g. In abnormal cases where the phase inequality is strong, the neutral conductor causes a significant current flow (potential difference with respect to the ground). In domestic applications, where the loads are normally single-phase, the neutral is the return path through which the current enters the distribution source. Regardless, all hot wire should be treated the same: do not touch hot wire unless there is no connected and operating power source. However, there are never ideal cases, and there is often a small degree of phase imbalance, resulting in a potential for the neutral conductor. The only problem is if you disconnect and touch them providing a path to earth through you. The fuse will blow. â This will create a short circuit as a large current which exceeds the fuse rating will from the live (240 V) to the neutral wire (0V) as that path has very low resistance. The neutral wire is often confused with ground wire, but in reality, they serve two distinct purposes. And the remote grounding rod might have a better connection. When you plug in something in the outlet, the neutral will be live, as it closes the circuit. The fuse will blow. And in both the cases it causes a fault condition called âEarth Faultâ. The most common example is light fixtures and lamps. The earth wire is the device that is designed to prevent you receiving an electric shock. sparx Rank: Project Manager. This is wrong, and potentially dangerous. If a final circuit with an N-E fault is not protected by an RCD, the cpc may become overheated, with a potential risk of fire. With normal AC power supply, nothing happens in industrial applications, i. H. When 3-phase current is used. If the live and earth wire were swapped where the wires connect to equipment then two things would happen. The two different 120 VAC lines are 180 degrees out of phase. What is the ground earth wire for neutral wire and unbalance cur neutral wire touches a earth electrical grounding nations home What Hens If You Touch The Neutral And Earth Of An ElectricalGround Fault Vs Short Circuit What S The DifferenceIs It Dangerous To Touch Neutral Wire Physics ForumsWhat Are The Differences Between Live Earth⦠Read More » In Short if neutral wire touches a earth wire, Nothing happen in case of AC 2 phase, The neutral wire should provide a return path for load currents. This role is filled by neutral wire. when you touch the neutral to earth, some of the current returns back through the earth wire instead of the neutral.. so the rcd sees more current going out than is coming back and knows it's lost some somewhere and turns off.. ColJack, 5 Mar 2009 #3. wayne306. It depends where they are swapped, and in what. Can an LED be used instead of a diode (because basically both are diodes)? NB "Capacitor" two parallel conducting surfaces seperated by insulating material, (ie, just like a twin & earth cable). Does AC current also rise and fall in sinusoidal movement, like voltage? Earthing Without the earth wire, if a fault occurs and the live wire becomes loose, there is a danger that it will touch the case. Danger of Open Service Neutral. If sufficient current flows along the cpc (earth) due to a neutral to Earth fault condition in a final circuit which is protected by an RCD, the RCD will trip. The white (neutral) wire should be connected to the silver-colored terminal. What does recovery mode mean on a thermostat? If the neutral (for that branch) is disconnected then the circuit is not complete and no current can flow. Share. The live wire touches the neutral wire. Nothing happen in case of AC 2 phase, The neutral wire should provide a return path for load currents. Why do you tie the neutral and ground together. Distribution lines providing three-phase current return this unbalanced current to the transformer stations, where it is connected to the mother earth and all potentials are discharged. What happens if you connect black wire to white wire? (1) In case of live wire touches the neutral wire (of the same system), than there will be a short circuit. Neutral wire carries the circuit back to the original power source. The live wire touches the earth wire. In this case a very large current suddenly flows because the metal case has a very small resistance. It is the role of the neutral wire to carry any current as a result of the imbalance in impedance of each of the phases loads. Contrary to popular belief, the neutral wire is not "safe" as it has current flowing on it under normal circuit operation. What is the real cube root of negative 64? Now if we were to break this wire or allow it to touch earth (ground or neutral) at some other location than the end of the toaster wires full length, we will have caused it to have less resistance that it would at it's full length. In such applications, when we connect the ground to the neutral, most of the current flows through the ground wire (remember that grounding has the least resistance because it is grounded near our house, compared to the neutral wire that is grounded passes through the entire redistribution transformer). Why is there no chloroplast in onion cells? Its as easy to get a belt from the neutral as it is from the live. Voltage Measurement between Neutral to Ground: A rule-of-thumb used by many in the industry is that Neutral to ground voltage of 2V or less at the receptacle is okay, while a few volts or more indicates overloading; 5V is seen as the upper limit.