Bane of our hobby...tank electrics.

Discussion in 'D.I.Y.' started by Trev Pleco, Nov 16, 2012.

  1. Greystoke
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    Allow me to explain that a 2[sup]nd[/sup] earth leakage unit can be a big help, particularly if its "mobile", like fitted to an extension lead.
    Earth leakage units measure the difference between the life and the neutral current. Ideally they should be exactly the same except in different direction. If they are NOT the same then - obviously - one of the circuits is showing a leak to earth.
    The trouble with earth leakage currents is that they are cumulative, ie: each earth fault adds to the total. So if you have a number of "suspect" appliances in operation they might together cause enough earth current to trip the unit. (Wet stove plates are notorious). Earth leakage units usually trip at 20mA, but you may have a number of devices with just 5 or 10mA fault currents. So, which appliance caused it to trip, and which appliance must be fixed or replaced?

    With just one earth leakage unit mounted fixed in the db board you will never - or with great difficulty - find out.
    This is where a 2[sup]nd[/sup] mobile unit will come in very handy in detecting the culprit, provided you have at least one outlet socket that is NOT connected through the ELU. It would work even better if you had a unit that actually measures the fault current, which will allow you to measure the extent of the fault. At more than 10mA you should have the appliance fixed or replaced.
     
  2. Rob Spies
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    O.k Cor
    I think most people here just want there tank setups to work. Maybe just some pointers, instead of confusing the situation. We use a EL tester to test the sensitivity of of the ELU,your stove,geyser and lights(accept for fluorescent light fittings)(I know you know there are more exceptions ,but let's keep it simple) need not be connected to the ELU as they cause nuisance tripping. If a person goes away for a while,just UNPLUG(not just switch off) all unused appliances to avoid one of them to tripping the ELU.
    Your post is accurate and I'm not criticizing,really just trying to keep it easy. You don't perhaps have shares in an electrical company somewhere because your going to give them good business! Please don't send customers to White River,I have enough problems with lightning strikes here!

    Rob
     
  3. Greystoke
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    I'm a retired Electrical Engineer Rob. I know this business, and I know the problems, but that insinuation is a bit unfair. I like your contributions otherwise, but I want to protect our members from rules and regulations that are of little consequence.
     
  4. Rob Spies
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    Meant no disrespect Cor and that was just a bit of humor from my side,sorry if you didn't like it.
    It's always nice having someone putting something new out there( your opinions or any one els) as I'm sure you know electrics keeps you on your toes cause you can never really understand it all.

    Regards
    Rob
     
  5. Rob Spies
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    I will also never give bad advice, we are entitled to our own opinions about rules and regulations,but the are there to protect lives. And in the field you have to use some common sence as well as experience.

    Regards
    Rob
     
  6. Greystoke
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    There was no ill intent, so let's shake hands on that. I'm really glad you're on this forum, because I know you can contribute a lot, but PLEASE go easy on the rules if they are of little consequence. I know they are intended to protect lives, but they also shouldn't make your life a nuisance, as some of them are.

    BTW: my son was a manager at the Brookland plantation (close to you). One day he told me that lightning blew his TV and his PC.
    Next time we visited we brought ±100m of 25mm ² copper cable, bought at scrap prices and two aluminium sheets 4mm thick, the size of his PC side panels.
    The copper cable went into his gutters around the house (shorted at the end) and - of course - the aluminium sheets were glued to his PC side panels.
    He never had another problem with lightning.
     
  7. Frana
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    My dad sad he bought the rdb db box @ Paragon Electrical Wholesalers but he is not 100% sure if it was there. The box use a three pin plug so the earth are still there for the few device that use the earth. I did use 2.5mm2 wire to wire the box. Will take a pic inside if I have time to open the box.
     
  8. Rob Spies
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    Hi Cor

    hands shook.

    Did you did you dig the copper and p.c into the ground? A bit confused.
    Currently I'm installing clear line surge protection in at a few places as the overhead lines are being struck. A lot of people forget about the farreday cage effect.

    Regards
    Rob
     
  9. Rob Spies
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    Hi Frana

    The 2.5mm will be acceptable for arguments sake.

    Regards
    Rob
     
  10. Greystoke
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    No,no.
    The rain gutter encirled the entire house, so we laid the cable in there and connected the ends. This way you get a shorted loop that - when subjected to lightning - will create an opposing magnetic field protecting the encircled area.
    The alum sheets on the sides of the PC work on the same principle. The TV we left alone.
     
  11. Rob Spies
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    Thanks Cor

    That's interesting, must say that's the first I've heard of that method.

    Regards
    Rob
     
  12. Greystoke
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    And it works!
    Probably better than these unsightly spikes erected next some houses.
     

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