lightning conductors

Discussion in 'Electricians' Talk' started by lloyd67, Sep 15, 2010.

  1. lloyd67

    lloyd67 New Member

    how do i test a lightning conductor? do i need any special equipment?
     
  2. don reed

    don reed New Member

    Just a stopwatch and a baton.
     
  3. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Lighting conductors do not come under 7671 and are a completely separate entity in their own testing rights

    It comes under BS 6651 and is excluded from BS 7671.

    Leave it alone unless your a lighting specialist

    si
     
  4. seneca2

    seneca2 New Member

    lighting specialist
    --------
    Lightning even!
     
  5. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Yeah thats it Sen. .:)
     
  6. Bazza-spark

    Bazza-spark Screwfix Select

    I think it's now BS EN 50164

    Kind regards

    BS
     
  7. OldGuy

    OldGuy New Member

  8. larnacaman

    larnacaman New Member

    Old Guy,

    The object of measuring down conductors on a lightning protection system is quite different to your method of testing.

    Each down conductor will have a test point that must be disconnected from it's ground rod. It's the ground rod(s) that needs testing. The copper tape is basically tested at each joint/connection with a low ohm meter.
    An overall test, is only performed as a confirmation test of the individual down conductor tests results...

    Your heavy duty jump leads wouldn't pass a low ohm joint test. ...lol!!. In fact, all lightning protection ground rod connections should actually be exothermically welded, as ALL testing should be from the test points on each down conductor.

    One last point, We tested one of these bits of kit you use, and found that it gave all sorts of bogus readings under different conditions. I asked the manufacturer about some these readings, and never heard a Dicky Bird back from them. So this bit of kit was sent back... Pointless having test equipment you don't or can't trust!!!
     
  9. OldGuy

    OldGuy New Member

    The object of measuring down conductors on a lightning protection system is quite different to your method of testing.

    I assume you are talking about three point testing. We now rarely use three point testing as most of the time we cannot.
    Firstly a lot of the ground rods we test are surrounded by concrete and tar. There is nowhere to insert the spikes. Where do you suggest I insert them?
    Secondly a large section of our work is on military bases and airfields. We cannot disconnect 95% of the ground rods due to operational reasons. The military and airfields are happy, after we ran trials and gave them the facts to back up our measurements, to accept this method.
    So do you suggest I just disconnect and shut down our national defense systems and airfields, just to connect a conventional ohm meter?

    One last point, We tested one of these bits of kit you use, and found that it gave all sorts of bogus readings under different conditions.
    You were obviously using it incorrectly!
     
  10. larnacaman

    larnacaman New Member

    OldGuy,

    I take your point about conventional testing in built up areas, i can see that your little gizmo would indeed come in very useful in such conditions. ...if only i could trust what it's telling me !!! lol!!

    I don't understand, why you would need to disconnect 95% of the ground rods though?? There tested individually one at a time!!! Also don't understand disconnecting at the ground rods, (They shouldn't be disconnectable anyway) surely it's far easier to test at the test point mounted on the buildings...

    The last time i was involved in MOD work at a military base, they had there own military E&M facilities, and certainly did all there own testing of base installations etc!!

    Maybe, just maybe that gizmo test kit has been improved since i last tested it. (around 2001) I did notice that there calling it ''Mark 11'' If i get the opportunity, I'll try ordering one, for the company and give it another chance...

    I know how to use, operate and also specify test equipment OldGuy. As i remember there were calibration test plates that came with this kit. Well the kit that i tested, couldn't be accurately calibrated with the test plates. It also didn't seem robust enough for regular day to day site use. The plastic casing seemed not to be of a good quality either, but it was a heavy old piece of kit, ...I'll give it that ..lol!!!
     
  11. edward current

    edward current Active Member

    if people understood how lightning conductors worked they would not be to bothered about testing them...

    they do not conduct fault currents to earth.... they pull neautrons from the earth and sort of push the lightning away... abit like two magnets, very complicated and also very very wierd..........
     
  12. larnacaman

    larnacaman New Member

    edward current,

    Are you serious, ...No need to test?? Push Lightning strikes away?? hahaha!!!
     
  13. edward current

    edward current Active Member

    told you nobody understands how they work..........
     
  14. larnacaman

    larnacaman New Member

    Edward,

    Perhaps you can explain then, why it is then, that a protected building fairly close to an unprotected building will in the vast majority of cases take the hit from a lightning strike?? Perhaps you can also tell us why our BS standard, American standard, Australian standard, and just about every other countries standards ALWAYS call for testing at regular intervals??

    One of the fundamentals of lightning protection is that it will attract a potential strike to it's self and NOT elsewhere. They work Edward by conducting the lightnings potential, safely to earth by means of a most direct path to earth with the least amount of damage to the structure it is there to protect!!!

    There are now basically two types of lightning protection, one that we are all here familiar with, and another that is known as an active protection system. These normally consist of a radioactive cell mounted on a designed length pole with a 3 spike layout positioned to protect a given building or area of a building if more than one is required. This type of system, actually sprays up positive ions to ATTRACT any potential lightning, which are made up of charged negative ions. So far from pushing away strikes, this is going out there looking for them...lol!!!

    Any comments Edward Current??
     
  15. edward current

    edward current Active Member

  16. larnacaman

    larnacaman New Member

    Edward Current,

    Read the gumpf you posted again, It's Quite clearly stated, Lightning air spikes ATTRACT The positive cloud charge in it's vicinity.... Don't say anything about pushing anything away though!!!
     
  17. larnacaman

    larnacaman New Member

    The non-conventional system is ESA (Early Streamer Emission)lightning protection System. Not totally recognised as such yet, but is an effective means of protection, and one that works over the 60 metre height range of conventional Franklin rod/Faraday cage systems.
     

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