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Thunderstorms - necessary to switch computer off? watch

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    (Original post by Lauren)
    LOL live on a hill and you'll get struck by lightning.

    what do u mean it's a hell of a house??!

    edit: what's the point in a lightning rod if it doesn't stop lightning?!
    LOL

    9 or 10 rooms on the ground floor? that's a lot.
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    (Original post by Lauren)
    LOL live on a hill and you'll get struck by lightning.

    what do u mean it's a hell of a house??!

    edit: what's the point in a lightning rod if it doesn't stop lightning?!
    It doesn't stop lightning. It attracts it.
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    (Original post by Mad Vlad)
    It doesn't stop lightning. It attracts it.
    i mean stop lightning hitting your house. it doesnt attract it. it just provides an easier path for the air.

    oh my house has some small rooms. like there's a room with just a washing machine in and tumble dryer. but some like the kitchen or living room were really big and got ruined.
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    (Original post by CrazyChemist)
    really? Isn't the lightning rod insulated? If not, what's the point?
    the point in a lightning rod is to carry the lightning to the groud. its not insulated and should have goo contact with earth. when you touch a live wire you get a shock because the neutral is connected to earth at the substation and various points along its journey. so what can happen is lightning goes into ground. it then goes back into earth rods from electricity supply. which then goes into neutral. which can then fry stuff depending on voltage. it also goes into the earth/neutral side, which can (very briefly) make some stuff live. altho chances of actually gettin a shock are almost none since there are at ground voltage
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    (Original post by Lauren)
    i mean stop lightning hitting your house. it doesnt attract it. it just provides an easier path for the air.

    oh my house has some small rooms. like there's a room with just a washing machine in and tumble dryer. but some like the kitchen or living room were really big and got ruined.
    Yes. A lightning rod however should be located away from power lines, substations and the like and ideally should be very tall and have a core of copper and have a direct route to earth - with the end of the earth rod extending far below the foundations of the building it protects.
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    (Original post by Lauren)
    i mean stop lightning hitting your house. it doesnt attract it. it just provides an easier path for the air.

    oh my house has some small rooms. like there's a room with just a washing machine in and tumble dryer. but some like the kitchen or living room were really big and got ruined.
    Well, actually it kinda does attract lightning - the lightning will go towards the lightning conductor instead of another path. That means the conductor attracts the lightning.

    Edit: still, 9 rooms is quite impressive.
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    (Original post by Mad Vlad)
    Yes. A lightning rod however should be located away from power lines, substations and the link and ideally should be very tall and have a core of copper and have a direct route to earth - with the end of the earth rod extending far below the foundations of the building it protects.
    bang on right.
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    (Original post by Mad Vlad)
    Yes. A lightning rod however should be located away from power lines, substations
    er... 1 problem with that... the substation reduces voltage from 11KV to 230/400 3phase/neutral. the neutral is connected to earth at the substation AND (with TNCS/PME) its connected to earth at various points along its way. so chances are, youll never be able to get it far away from a DNO earth rod
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    (Original post by MorbidAngel)
    the point in a lightning rod is to carry the lightning to the groud. its not insulated and should have goo contact with earth. when you touch a live wire you get a shock because the neutral is connected to earth at the substation and various points along its journey. so what can happen is lightning goes into ground. it then goes back into earth rods from electricity supply. which then goes into neutral. which can then fry stuff depending on voltage. it also goes into the earth/neutral side, which can (very briefly) make some stuff live. altho chances of actually gettin a shock are almost none since there are at ground voltage
    I think I'll take your word on it.
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    (Original post by CrazyChemist)
    I think I'll take your word on it.
    finally. someone who pays attention to the sparky
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    (Original post by MorbidAngel)
    er... 1 problem with that... the substation reduces voltage from 11KV to 230/400 3phase/neutral. the neutral is connected to earth at the substation AND (with TNCS/PME) its connected to earth at various points along its way. so chances are, youll never be able to get it far away from a DNO earth rod
    How susceptible would a substation be to such a charge through the earth? I would imagine that most of the charge would have been dissipated and only a small amount making contact with the earth rod on the substation. Surely there must be a design feature on the substation to protect it from such damage?
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    (Original post by Mad Vlad)
    How susceptible would a substation be to such a charge through the earth? I would imagine that most of the charge would have been dissipated and only a small amount making contact with the earth rod on the substation. Surely there must be a design feature on the substation to protect it from such damage?
    there is a very small chance of the spike going back into the substation. also, in many older substations there is actually no protection on the secondary side. its on the primary. so it basically has to have high currents on the primary before itll blow fuses. and even if the substaion did have double pole breakers, if the supply in TNCS, then it cant disconnect the earth from the neutral. it can with TNS or TT tho

    chances of damage due to it going back thru DNO earth rods are pretty much 0, but in theory it could happen
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    you need one of these: http://www.newscientist.com/article....mg15821311.000
 
 
 
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