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Connecting Neutral/Earth together

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    #21
    Re: Connecting Neutral/Earth together

    Originally posted by Dannyx View Post
    Then there were others where the chassis had the N wire tied to it, making things a bit......confusing. I know it's "neutral", but shouldn't this be separate from E ?
    No. There are several types of Earthing systems.
    IT, TT, TN
    Usually the household subscribers are connected using one of the variations of the TN, so the neutral is grounded multiple times - from the transformer itself to the electrical panel - the Neutral is connected to the Earth, thus making PEN.
    Depending on the type of Earthing system we have 2 and 3 wire systems...and so on. This is why if you touch the LIVE conductor, you will be electrocuted. Because you close the circuit between the Live(230V in your case) and Neutral that is grounded, so techically you can close the circuit between any object connected to the earth with low enough resistance and the LIVE conductor itself.
    There are other types of Earthing systems, where the Neutral is not grounded and it's insulated from the ground, so you have to touch both neutral and LINE to be electrocuted or where the Earth is not connected to the Neutral, so the neutral can have higher potential(voltage) than the ground.
    In 2 wire systems the protective grounding works with connecting the NEUTRAL to the GROUND terminals of the power socket using a piece of wire as a bridge. Not recommended, because if the Neutral wire is damaged, the whole body of the metal appliance that has to be grounded would become with the potential of the live wire, waiting for someone to close the circuit to the ground by touching it. Because the current flows from the L to the N and via the bridge to the P to the metal body of the appliance via the grounding wire. This is why now we have 3 wire systems, residual current devices and from the apartment electrical panel there are different conductors coming to the P and N terminals of the electrical sockets, so the Earth and Ground are pseudo separated, while they still have the same potential, so the residual current breakers could work properly.
    In Bulgaria we have a requirement that every new building has to have 3 wire systems from the electrical panel inside the apartments and the neutral has to be grounded inside the electrical panel, as well as we are obligated to install residual current devices in every new building(built after year 2006 if I recall correctly) But we have many old buildings with 2 wire systems, that have only L and P and the only way to keep these safe is to make sure that N is not damaged and connect P terminals to N.
    Last edited by televizora; 11-15-2019, 06:08 PM.
    Useful conversions. I don't "speak" imperial. Please use metric, if you want to address me.
    1km=1000m=100000cm, 1inch=2.54cm, 1mile=1609.344meters, 1ft=30.48cm 1gal(US)=3.785liters, 1lb=453grams, 1oz=28.34grams

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