Give that non-contact tester to your kids to play with, they are nothing much more than a toy, but they do generate a lot of profit for the big box home stores. After all, there are no ground-referenced components on the input to the power supply that a voltage potential on the neutral conductor could upset. $\begingroup$ It can't. 4) Bad supply circuit: 4.1) Live conductor is leaking to: 4.1.1) Another live conductor but not on the same RCCB. The neutral wire is associated with many misunderstandings and myths related to power quality. Neutral is return path for an AC circuit which is supposed to carry current in normal condition. 5. A loose neutral wire is also the cause of the majority of electrical fires. === === This is known as a "Disconnected Neutral (Open neutral)" fault condition. At any given time, whatever current flows through the live wire, an equal amount (*note 2) flows in the opposite direction through the neutral wire. On this exterior GFCI, the tester showed it had a ground. In fact, the neutral wire and the hot wire are interchangeable from the point of view of protected equipment. This black wire IR drop (2.4V) is measurable by taking the difference between the no-load hot-to-ground voltage (121.6V) and the load hot-to-ground voltage (119.2V). Let's assume that the X represents the neutral connection, then it the above scenario we are switching the neutral to the lamp which already has neutral. What possible effect could neutral return losses have upon a system with this configuration? An appliance such as a fridge has two current carrying conductors. > 1) Would this explain both the apparent live neutral reading in our > main meter box and the tripping of the RCDs? Also removing the offending lamp from the plampholder would break the supplyto the neutral killing your live neutal. So a Neutral to Earth Leakage fault is when a fault develops and the neutral and earth are connected together sufficiently to cause a current flow out of the neutral conductor and into the earth (or visa versa). Been to a house today to do a EICR every socket in the house was wired with neutral earth reverse. The neutral should be white and goes to the wider plug. As the motorhome is protected by a ELCB that will switch off both live and neutral in the event of an earth fault you are protected. For example, if L1 has a large load and L2/L3 are lightly loaded, the neutral voltage will be pulled towards L1, causing the L2-N and L3-N voltages to became much larger than their nominal voltage. As long as you understand this, then reverse polarity becomes less of a worry. The question is, who swapped them round. the terms “reverse polarity” and “open ground.” Reverse polarity is a condition which adversely affects a 120 volt (nominal) electrical receptacle outlet. Neutral. The neutral voltage will drift towards whichever line is the most loaded (as it forms a voltage divider). Or to put it another way, Live and earth have been swapped round. A loose neutral wire can cause abnormal arcing around its point of connection, usually resulting in the neutral wire becoming unusually hot, burning its insulation off and even causing damage to its surroundings. Step 1, find the right breaker in your main box and turn off the power to the circuit, step 2 remove the outlet and swap the neutral and hot leads on the outlet. We have only created a loop. In fact a fuse does not 'trip', it either blows or melts depending on the type of … Dia Hot neutral reverse typically occurs when the hot wire, (it is supposed to be black) is attached to the neutral screw on the outlet. The hot (black wires) were still connected and the breaker was back on, but without the neutral path the light won’t work, and the neutral ahead of that open splice will have power on it, the same as the hot wire. The voltage of the neutral conductor is only nominally 0 volts (i.e., zero volts in name only.) It is also why your volt meter shows no voltage difference between Live and Neutral because you are actually checking between Neutral and earth. If you have an open neutral in the panel, the lights will dim and get brighter. Try leaving the neutal disconected and see what light is not working, simple way to test. This current may be because of many reasons, primarily because of phase current imbalance and some time because 3rd and 5th harmonics also. An … 2) Normal sum of the accumulated leakage on all connected appliances means the RCCB is borderline. The neutral wire completes the circuit, giving a return path for the current. A live and neutral reversed, whilst potentially hazardous will not cause a fuse to 'trip'. Live to earth reverse means that the Live and Earth are reversed. New panels that were all romex but half the receptacles in the house had no grounds. This happens when the hot and neutral wires get flipped around at an outlet, or upstream from an outlet. I have used the logic that you have provided regarding the X and Y. If you have an open neutral at an outlet, the outlet and all those connected after it won't work, but they all will still be energized. Yes and no. Hot & Ground Reverse If the wire is not a superconductor, then the voltage must be different at every point along the length of the wire while current is flowing. Possible Causes of fault to try to isolate 1) Bad RCCB. The reversed neutral and hot is easy. In North America, the neutral and earth (ground) conductors are bonded together at only one point: in the service entrance panel. The Alternating Current do not have polarity, but Live wire is dangerous and neutral wire can safely be touched. The black wire should be the hot wire and it goes to the thin plug. Reversed polarity creates a potential shock hazard, but it's usually an easy repair. The Neutral of your service is connected to Earth ground at the service panel. In fact, UL power supply tests reverse the polarity of voltages applied to a power supply. If the power leads are reversible you could get the situation as seen in the above picture. 2] No reading between the hot and the neutral but 120V between the hot and ground and 120V between the neutral and ground indicates an open neutral. Agree 100%. It results from the incorrect wiring (reversing) of the electrical system hot and neutral wires to the receptacle outlet. At that point the voltage between the two should obviously be zero unless there’s a problem. 3) Bad appliance or appliances. i have test a wall socket and have found 230volts in the live cable and 230volts in the neutral i have been told this is called a live/earth reverse but would like to find out why it is happening or possible causes … My experience when a plug-in receptacle tester indicates Hot-Grd Reverse that the problem has always been no neutral. The hot wire is supposed to be attached to the hot screw (the gold one), and the neutral wire should be attached to the neutral screw (the silver one). Fixing a hot wire and a ground wire that are reversed is as easy as unscrewing and switching the wires on the receptacle and screwing them tight again. One is the hot, and the other is the Identified Conductor, often incorrectly called the neutral. This should be the only point the ground comes in contact with the neutral. There's a loose neutral somewhere in that circuit or upstream, it's correct that outlet testers that have the "hot & ground reverse" function will light up when it is a problem with the neutral, that function just leads people to think the fault exists with the hot and ground instead of the neutral … I found so receptacles in my house that were apparently wired in reverse (according to a receptacle tester). Similarly, when the current flows in the live wire, it flows out the neutral. In a circuit protected by an RCD,such as an RCCB or RCBO, the circuit fault conditions causes … 3] No continuity between the neutral and ground - Check for tripped GFCI device first 4] If all the branch circuit breaker are on you have a bad connection on the hot or neutral wires. Causes of Neutral Wires to Have 120 Volt Readings ... because getting in the middle of any live circuit can cause an electrical shock which could be fatal.) 4.4— The multimeter will not show any voltage between the Hot and the Gnd terminals on outlets #1 & 2 of circuit G and outlets #2 & 3 of circuit H, but 120 Volts between the Neutral and Gnd terminals making these outlets lethally hazardous by placing a live voltage on every grounded part of all appliances plugged into it. I always thought RCDs were > only concerned with earthing faults, not live/neutral reverse polarity > type problems > Depending how it is wired and what you use might make one circuit breaker trip. The white wire IR drop is as easy to measure as neutral-to-ground voltage, but the increased current causes an IR drop on the black wire as well as the white wire. Reverse Polarity is a term usually used to describe where a 230V device, like a household appliance, e.g Toaster, has been wired incorrectly at the plug so that the Live/+ power travels down the Neutral/- wire of the 3 wire cable. The reason is that, the neutral is the point at which all electrically balance voltage which is 120 degree phase shift from each other is connected together. As a result, the ground and live are at the same voltage and there's a 120V difference between ground and neutral. Seeing as you have disconected the neutral you technically are getting a supply from the sw wire of the light, throught the lamp. 4.1.2) Another Neutral but not on the same RCCB. Without a continuous path back to the panel, and the neutral buss bar, the voltage has no place to go to complete the circuit. In reality, some had connected the ground for that are to the live wire with no connected to actual ground. The neutral wire completes the circuit for every 120-volt device in the house. 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