Anonymous
Anonymous asked in Science & MathematicsEngineering · 4 weeks ago

People say that in the UK the neutral is connected to earth either at the power station or more locally.?

So I ask this question. If an appliance is sold having metal some parts but no earth connection, then is it possible to wire the neutral to the metal part instead of the earth and still be safe. For example, in the case where no earth lead is available.

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  • Bob
    Lv 7
    3 weeks ago

    No, the item you describe is known as 'double insulated' having functional and protective secondary insulation to prevent danger in the event of the functional insulation failing. This product does not need an earth.

    You should NEVER use the neutral as an earth, only the supply providers can do that in their supply system.

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  • 4 weeks ago

    The simple answer is NO. The more complex answer is go to a library, get a book on AC powered appliances and read it. It wouls be dangerous to have the neutral connected to the frame of an oven during a lightning storm for instance. There are many other issues involved.

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  • 4 weeks ago

    No.

    If the appliance has a significant amount of metal parts. e.g. a metal case, then it must have an Earth terminal.

    If the appliance has only two wires (live/neutral), then it must be double insulated (isolating transformer and the few exposed metal parts nowhere near the electrical circuits)

    If you were to connect neutral to an exposed metal part and there was a neutral fault - e.g. neutral wire broken in the ring main between appliance and consumer unit, then your  metal parts would be at live (240v) voltage!

    If the appliance ships with just two wires and has some exposed metal, then it is a double insulated device and the metal parts can (and should) be left floating and unconnected to anything.

    • Born Yesterday
      Lv 7
      4 weeks agoReport

      Hi, and thank you for the reference. I have responded to many polyphase open neutrals where stray Voltage was present in appliances with defective grounding and occupants had evacuated due to  random severe shocks. Bottom line ground is not a substitute for neutral.

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  • 4 weeks ago

    no - that's a view

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  • 4 weeks ago

    YES, IT IS SAFE IF THE METAL CASE IS 100% SURE CONNECTS TO NEUTRAL LINE WHERE HAS ZERO VOLTAGE !

    AND SURE SAFE TO TOUCH THE NEUTRAL LINE WITH BARE HAND BEFORE ITS VOLTAGE IS EQUAL TO ZERO.

    • Bob
      Lv 7
      2 weeks agoReport

      The use of irony only confuses the stupid.

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