Recent content by studentspark

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    How do you deal with old, dead cables?

    If i have a cable that I am unsure of, say just cut and hanging there. I isolate, and terminate the conductors in a connector block, to enable testing. If I am happy that that cable is not connected to any source of power. I strip out if possible , or terminate it, as if it was live. Even if...
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    How do you deal with old, dead cables?

    Always presume live, or can become live. The only way to know for sure is trace them to a junction box. Only strip out cables when you can find both ends. Something that disappears into a wall or void, terminate as if it was live. I've found live lead covered cable in a house that was 'rewired'...
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    Buying a House - serious electrical defects

    If you love the house buy it. A rewire in the scheme of things is not that big a deal.
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    Supplementary Bonding Revisited

    No worries at all John, I've been on and off with this for many years, so no rush. :)
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    Supplementary Bonding Revisited

    Hi EFLI Yes this is an academic exercise, I suppose. But if you don't get the theory clear in your mind, you are just going through the motions. Installing MPB, is just something we get told to do. And I understand the need for it, but not the science behind it, well only in a basic way. But...
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    Supplementary Bonding Revisited

    erroneous post removed at OP request
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    Supplementary Bonding Revisited

    With Supplementary bonding all but done away with (for now) and the additional protection of the RCD, now being found to be wanting, because the AC types we have been installing, can't deal with the DC modern equipment uses. You wonder if installations have been made less safe.
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    Supplementary Bonding Revisited

    Indeed yes. But thats at the maximum (Tns) Ze. I generally never find it that high. Usually less than 0.2Ω.
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    Supplementary Bonding Revisited

    I put this together. I was listening to the Footie and drinking beer, whilst doing :whistle: but I think my sums are correct
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    Supplementary Bonding Revisited

    I'm getting it John :) Been reading up on kirchhoff's law. As you say John. This 50V is not really achievable. Its interesting that the very low EFLI which we are encouraged to obtain, increases the touch voltage. And I can see more clearly, the importance of supplementary bonding, which...
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    Supplementary Bonding Revisited

    I fear I will drive you chaps mad.... I do understand the concept of potential difference. Voltage needs to be different at two points for current to flow. What I am struggling with is. With no fault, all the Extraneous and Exposed CP are at the same potential. MET voltage, as they are all...
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    Supplementary Bonding Revisited

    Yes this is making sense, but I am still pondering the CPC to the light switch Oh dear ..Sorry John So, how does the voltage appear on the light switch plate - It has to be by the CPC. So there is a voltage on it. So we have a voltage, we have a resistance, so we must have some current. ...
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    Supplementary Bonding Revisited

    OK. I fear I'm going backwards, but I need to get something clear in my head please John, before I unleash my next confusing drawing. MET potential, and how that affects the connected conductors... Im getting a bit confused by the volt drop in a conductor when no current is flowing. So in CPC...
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    Supplementary Bonding Revisited

    Excellent, some good learning going on here. Really appreciate your patience, and time.
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    Supplementary Bonding Revisited

    :) Well no...and well yes kind of. As in say a radial socket circuit. Nothing is flowing if no load attached. You calculate the volt drop based on a expected load. When unloaded, the conductors just sit there waiting to be called into action ( sorry for the not technical terms) There is a...
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