Lightning Protection for Tall Buildings - Mandatory?

Discussion in 'Electronic Design' started by Aaron407, Aug 3, 2006.

  1. Aaron407

    Aaron407 Guest

    Hi everybody,

    I'm not sure if this is the right group to post this in (correct me if
    it's not), but I could really use some help. I'm an electrical engineer
    looking into lightning protection for buildings, but in my search I
    have found the information to be quite ambiguous as to whether
    lightning protection is actually mandatory or not. I am looking at a
    possible install on a mill building about 150' tall at a potash mine
    here in Saskatchewan, Canada.

    Could anyone direct me to any resources (American or Canadian) which
    state cut and dried if/when lightning protection is mandatory? I have
    looked through the CAN/CSA-B72-M87 and NFPA 780, but both avoid
    explicitly saying anything along the lines of "lightning protection is
    not mandatory, but highly recommended...". They use terms at the
    beginning like 'required', but continue with words such as
    'recommended' and 'should', which have confused me to this point.

    Can anyone enlighten me? It would be greatly appreciated.

    Thanks.

    -407
     
    Aaron407, Aug 3, 2006
    #1
    1. Advertising

  2. Aaron407 wrote:
    >
    > Hi everybody,
    >
    > I'm not sure if this is the right group to post this in (correct me if
    > it's not), but I could really use some help. I'm an electrical engineer
    > looking into lightning protection for buildings, but in my search I
    > have found the information to be quite ambiguous as to whether
    > lightning protection is actually mandatory or not. I am looking at a
    > possible install on a mill building about 150' tall at a potash mine
    > here in Saskatchewan, Canada.
    >
    > Could anyone direct me to any resources (American or Canadian) which
    > state cut and dried if/when lightning protection is mandatory? I have
    > looked through the CAN/CSA-B72-M87 and NFPA 780, but both avoid
    > explicitly saying anything along the lines of "lightning protection is
    > not mandatory, but highly recommended...". They use terms at the
    > beginning like 'required', but continue with words such as
    > 'recommended' and 'should', which have confused me to this point.
    >
    > Can anyone enlighten me? It would be greatly appreciated.
    >
    > Thanks.
    >
    > -407



    I would check with the local government's building & zoning people.
    They are the people you have to satisfy, anyway.

    news:alt.engineering.electrical is a group that deals more in the
    power distribution side of EE.


    --
    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
     
    Michael A. Terrell, Aug 3, 2006
    #2
    1. Advertising

  3. Aaron407

    Rich Grise Guest

    On Thu, 03 Aug 2006 13:56:42 -0700, Aaron407 wrote:

    > Hi everybody,
    >
    > I'm not sure if this is the right group to post this in (correct me if
    > it's not), but I could really use some help. I'm an electrical engineer
    > looking into lightning protection for buildings, but in my search I have
    > found the information to be quite ambiguous as to whether lightning
    > protection is actually mandatory or not. I am looking at a possible
    > install on a mill building about 150' tall at a potash mine here in
    > Saskatchewan, Canada.
    >
    > Could anyone direct me to any resources (American or Canadian) which state
    > cut and dried if/when lightning protection is mandatory? I have looked
    > through the CAN/CSA-B72-M87 and NFPA 780, but both avoid explicitly saying
    > anything along the lines of "lightning protection is not mandatory, but
    > highly recommended...". They use terms at the beginning like 'required',
    > but continue with words such as 'recommended' and 'should', which have
    > confused me to this point.
    >
    > Can anyone enlighten me? It would be greatly appreciated.
    >


    Whether it's mandatory or not is irrelevant. Do it anyway. Just put some
    sharp spikes on the roof, and then either bond them to the steel frame
    or to some heavy cable to a good ground.

    The reason for the lightning rods isn't to absorb a strike - it's to
    dissipate the charge above the building before it builds up enough
    to cause a strike; that's why you use pointy ends - the corona drains
    off the charge, at least right above your structure.

    Good Luck!
    Rich
     
    Rich Grise, Aug 4, 2006
    #3
  4. Building lightning protection requirements vary by province, each with
    their own idea of which department is responsible. Could be part of
    the electrical, fire, building codes, or something else completely.
    I'd suggest contacting one of the companies doing rooftop antenna
    installations such as Radian or Westower & ask them who does the
    inspections on the lightning protection systems they install, that
    should point you in the right direction. If you don't have experience
    with these systems I'd seroiusly suggest farming it out to someone who
    does, for supposedly simple systems theres a lot of little "gotchas"
    in there.

    H.



    On 3 Aug 2006 13:56:42 -0700, "Aaron407" <>
    wrote:

    >Hi everybody,
    >
    >I'm not sure if this is the right group to post this in (correct me if
    >it's not), but I could really use some help. I'm an electrical engineer
    >looking into lightning protection for buildings, but in my search I
    >have found the information to be quite ambiguous as to whether
    >lightning protection is actually mandatory or not. I am looking at a
    >possible install on a mill building about 150' tall at a potash mine
    >here in Saskatchewan, Canada.
    >
    >Could anyone direct me to any resources (American or Canadian) which
    >state cut and dried if/when lightning protection is mandatory? I have
    >looked through the CAN/CSA-B72-M87 and NFPA 780, but both avoid
    >explicitly saying anything along the lines of "lightning protection is
    >not mandatory, but highly recommended...". They use terms at the
    >beginning like 'required', but continue with words such as
    >'recommended' and 'should', which have confused me to this point.
    >
    >Can anyone enlighten me? It would be greatly appreciated.
    >
    >Thanks.
    >
    >-407
     
    Howard Eisenhauer, Aug 4, 2006
    #4
  5. Aaron407

    jasen Guest

    On 2006-08-04, Rich Grise <> wrote:
    > On Thu, 03 Aug 2006 13:56:42 -0700, Aaron407 wrote:
    >
    >> Hi everybody,
    >>
    >> I'm not sure if this is the right group to post this in (correct me if
    >> it's not), but I could really use some help. I'm an electrical engineer
    >> looking into lightning protection for buildings, but in my search I have
    >> found the information to be quite ambiguous as to whether lightning
    >> protection is actually mandatory or not. I am looking at a possible
    >> install on a mill building about 150' tall at a potash mine here in
    >> Saskatchewan, Canada.
    >>
    >> Could anyone direct me to any resources (American or Canadian) which state
    >> cut and dried if/when lightning protection is mandatory? I have looked
    >> through the CAN/CSA-B72-M87 and NFPA 780, but both avoid explicitly saying
    >> anything along the lines of "lightning protection is not mandatory, but
    >> highly recommended...". They use terms at the beginning like 'required',
    >> but continue with words such as 'recommended' and 'should', which have
    >> confused me to this point.
    >>
    >> Can anyone enlighten me? It would be greatly appreciated.
    >>

    >
    > Whether it's mandatory or not is irrelevant. Do it anyway. Just put some
    > sharp spikes on the roof, and then either bond them to the steel frame
    > or to some heavy cable to a good ground.
    >
    > The reason for the lightning rods isn't to absorb a strike - it's to
    > dissipate the charge above the building before it builds up enough
    > to cause a strike; that's why you use pointy ends - the corona drains
    > off the charge, at least right above your structure.


    that sounds like a load of crap to me.

    If you put ions into the air above a structure that'll attract lightning
    in much the same way as making it taller would.

    Bye.
    Jasen
     
    jasen, Aug 5, 2006
    #5
  6. Aaron407 wrote:
    > Hi everybody,
    >
    > I'm not sure if this is the right group to post this in (correct me if
    > it's not), but I could really use some help. I'm an electrical engineer
    > looking into lightning protection for buildings, but in my search I
    > have found the information to be quite ambiguous as to whether
    > lightning protection is actually mandatory or not. I am looking at a
    > possible install on a mill building about 150' tall at a potash mine
    > here in Saskatchewan, Canada.
    >
    > Could anyone direct me to any resources (American or Canadian) which
    > state cut and dried if/when lightning protection is mandatory? I have
    > looked through the CAN/CSA-B72-M87 and NFPA 780, but both avoid
    > explicitly saying anything along the lines of "lightning protection is
    > not mandatory, but highly recommended...". They use terms at the
    > beginning like 'required', but continue with words such as
    > 'recommended' and 'should', which have confused me to this point.
    >
    > Can anyone enlighten me? It would be greatly appreciated.


    Beside mandatory or not, there could be the case when
    an insurance refuses to pay if not installed...

    Rene
    --
    Ing.Buero R.Tschaggelar - http://www.ibrtses.com
    & commercial newsgroups - http://www.talkto.net
     
    Rene Tschaggelar, Aug 5, 2006
    #6
  7. Aaron407

    Rich Grise Guest

    On Sat, 05 Aug 2006 06:22:56 +0000, jasen wrote:

    > On 2006-08-04, Rich Grise <> wrote:


    >> The reason for the lightning rods isn't to absorb a strike - it's to
    >> dissipate the charge above the building before it builds up enough
    >> to cause a strike; that's why you use pointy ends - the corona drains
    >> off the charge, at least right above your structure.

    >
    > that sounds like a load of crap to me.
    >
    > If you put ions into the air above a structure that'll attract lightning
    > in much the same way as making it taller would.



    Well, I'll be. According to howstuffworks.com, you're right. It doesn't
    dissipate the charge, it just diverts the stroke so it doesn't burn the
    house down. :)

    If you learn something new every day, does that mean I can go back to bed
    now? ;-)

    Thanks!
    RIch
     
    Rich Grise, Aug 5, 2006
    #7
  8. Aaron407

    Guest

    On Sat, 05 Aug 2006 18:35:54 GMT, Rich Grise <> wrote:

    >On Sat, 05 Aug 2006 06:22:56 +0000, jasen wrote:
    >
    >> On 2006-08-04, Rich Grise <> wrote:

    >
    >>> The reason for the lightning rods isn't to absorb a strike - it's to
    >>> dissipate the charge above the building before it builds up enough
    >>> to cause a strike; that's why you use pointy ends - the corona drains
    >>> off the charge, at least right above your structure.

    >>
    >> that sounds like a load of crap to me.
    >>
    >> If you put ions into the air above a structure that'll attract lightning
    >> in much the same way as making it taller would.

    >
    >
    >Well, I'll be. According to howstuffworks.com, you're right. It doesn't
    >dissipate the charge, it just diverts the stroke so it doesn't burn the
    >house down. :)
    >
    >If you learn something new every day, does that mean I can go back to bed
    >now? ;-)
    >
    >Thanks!
    >RIch



    I inspected some toll booths at exit 99 on I-75 in Florida. They were
    planning on these little boxes getting hit with people in them. The
    biggest thing they did was be sure it was a great grounding system.and
    all the metal was bonded to it.
     
    , Aug 7, 2006
    #8
  9. wrote:
    >
    > I inspected some toll booths at exit 99 on I-75 in Florida. They were
    > planning on these little boxes getting hit with people in them. The
    > biggest thing they did was be sure it was a great grounding system.and
    > all the metal was bonded to it.



    Yes, lightning loves all kinds buildings here in Florida. It hit one
    of those old fashioned concrete awnings that was built in a restaurant
    parking lot for the car hops to stay dry. It also hit the corner of the
    main building, and the small STL tower in the parking lot and two C-band
    sat dishes where I lost all the LNAs and the CARS (STL) transmitter.

    It vaporized the rebar and the large threaded rods that held the roof
    panels on the concrete columns. It exploded damp concrete in both
    structures which went through the various breaker boxes and electronics
    while destroying almost everything electrical, after some of the old
    building grounds failed.

    It was in Leesburg, and was the original studio and offices of WACX
    TV, Ch 55. It took weeks to repair all the damage, but I managed to
    have the phones and lights working an hour after the office opened, then
    got on the phones to arrange for rental equipment to keep the station on
    the air.

    I replaced the entire ground system, and redid all the cabling into
    bonded steel conduit. It cost a wad of money, and we were self insured.

    On top of that it was my first day as the only engineer on staff. :(


    --
    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
     
    Michael A. Terrell, Aug 7, 2006
    #9
  10. Aaron407

    Guest

    On Mon, 07 Aug 2006 05:01:22 GMT, "Michael A. Terrell"
    <> wrote:

    > It vaporized the rebar and the large threaded rods that held the roof
    >panels on the concrete columns. It exploded damp concrete in both
    >structures which went through the various breaker boxes and electronics
    >while destroying almost everything electrical, after some of the old
    >building grounds failed.



    This stuff happens when the bonding/grounding is not secure. If you
    give the lightning a clean path to ground, that is where it goes. I
    bet they did not have all that rebar tied together and it was just
    stuck in the wet mud at the top of the columns.
    At MM99 we probably had close to a half mile of 1/0 copper ground ring
    along with a bunch of 40' rods around the ring and Ufers on all the
    buildings, tied to the steel in the roadbed and duct banks. Any
    significant chunk of metal was bonded along with the normal bonding of
    "building steel". They did ground testing on every rod and they shot
    so many CadWelds it was like the 4th of July for a week around there.
    There were no clamps used on any buried ground connection in the
    concrete or underground
    I was surprised at all the engineering that goes into a toll booth and
    the systems they use. For one thing there is 5 tons of "fresh air
    makeup" A/C blowing into the booths pulling air from the woods behind
    the service building. It keeps the CO down in the booth. The duct
    banks for the electrical, computer and control systems are about 8
    feet down to protect them from the traffic. I really didn't have much
    to look at as an electrical inspector since everything was supervised
    by an engineer and inspected by about 3 other guys before I saw it.
    Things were so far above and beyond the NEC it was just a sight seeing
    trip.
     
    , Aug 7, 2006
    #10
  11. wrote:
    >
    > On Mon, 07 Aug 2006 05:01:22 GMT, "Michael A. Terrell"
    > <> wrote:
    >
    > > It vaporized the rebar and the large threaded rods that held the roof
    > >panels on the concrete columns. It exploded damp concrete in both
    > >structures which went through the various breaker boxes and electronics
    > >while destroying almost everything electrical, after some of the old
    > >building grounds failed.

    >
    > This stuff happens when the bonding/grounding is not secure. If you
    > give the lightning a clean path to ground, that is where it goes. I
    > bet they did not have all that rebar tied together and it was just
    > stuck in the wet mud at the top of the columns.
    > At MM99 we probably had close to a half mile of 1/0 copper ground ring
    > along with a bunch of 40' rods around the ring and Ufers on all the
    > buildings, tied to the steel in the roadbed and duct banks. Any
    > significant chunk of metal was bonded along with the normal bonding of
    > "building steel". They did ground testing on every rod and they shot
    > so many CadWelds it was like the 4th of July for a week around there.
    > There were no clamps used on any buried ground connection in the
    > concrete or underground
    > I was surprised at all the engineering that goes into a toll booth and
    > the systems they use. For one thing there is 5 tons of "fresh air
    > makeup" A/C blowing into the booths pulling air from the woods behind
    > the service building. It keeps the CO down in the booth. The duct
    > banks for the electrical, computer and control systems are about 8
    > feet down to protect them from the traffic. I really didn't have much
    > to look at as an electrical inspector since everything was supervised
    > by an engineer and inspected by about 3 other guys before I saw it.
    > Things were so far above and beyond the NEC it was just a sight seeing
    > trip.



    The building was an old restaurant, converted into the studios and
    offices of a low power UHF TV station. it all happened before I was
    hired, and from the look of things it had survived several previous
    strikes without damage, but it appeared that there were multiple strikes
    that morning and there wasn't time for the copper bonding to cool down
    between strikes. That was in 1988, and as far as I know, there has been
    no new damage since then. The studio and control room was bonded with
    1/8" * four inch copper, but the multiple power panels were not well
    bonded, so the ground potential flowed though them and melted them. The
    main grounding was at the tower and sat dishes. They survived, but the
    older parts didn't. They were about 40 years old at the time, and
    probably not up to code for new work. Just a couple miles away WLBE's
    towers sit in a swamp and get multiple strikes on a regular basis. The
    engineer has had to replace the conduits to the towers several times
    because there was so much crap fused to the walls that they couldn't
    replace the wires, again. When I lived in lake County I could see the
    lightning heading for the towers, then it would split and hit all of
    them. Sometimes the strikes were just seconds apart. On the other hand,
    the new WACX tower in Orange City is 1749 feet of steel that has been
    hit, but hadn't suffered any damage that I know of. It was over a
    million dollars to build and it gets annual maintenance where bolts are
    inspected and replaced, as needed. There is a freight elevator to the
    top, but I never had the two hours needed to go up, and back down while
    I was there doing weekly transmitter maintenance.

    They had just installed equipment from Innovative Technology
    http://www.itvss.com/ to protect the electrical and data systems at all
    four sites when I left the station to build Ch 58 in Destin, Florida.


    --
    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
     
    Michael A. Terrell, Aug 7, 2006
    #11
  12. Aaron407

    joseph2k Guest

    wrote:

    > On Mon, 07 Aug 2006 05:01:22 GMT, "Michael A. Terrell"
    > <> wrote:
    >
    >> It vaporized the rebar and the large threaded rods that held the roof
    >>panels on the concrete columns. It exploded damp concrete in both
    >>structures which went through the various breaker boxes and electronics
    >>while destroying almost everything electrical, after some of the old
    >>building grounds failed.

    >
    >
    > This stuff happens when the bonding/grounding is not secure. If you
    > give the lightning a clean path to ground, that is where it goes. I
    > bet they did not have all that rebar tied together and it was just
    > stuck in the wet mud at the top of the columns.
    > At MM99 we probably had close to a half mile of 1/0 copper ground ring
    > along with a bunch of 40' rods around the ring and Ufers on all the
    > buildings, tied to the steel in the roadbed and duct banks. Any
    > significant chunk of metal was bonded along with the normal bonding of
    > "building steel". They did ground testing on every rod and they shot
    > so many CadWelds it was like the 4th of July for a week around there.
    > There were no clamps used on any buried ground connection in the
    > concrete or underground
    > I was surprised at all the engineering that goes into a toll booth and
    > the systems they use. For one thing there is 5 tons of "fresh air
    > makeup" A/C blowing into the booths pulling air from the woods behind
    > the service building. It keeps the CO down in the booth. The duct
    > banks for the electrical, computer and control systems are about 8
    > feet down to protect them from the traffic. I really didn't have much
    > to look at as an electrical inspector since everything was supervised
    > by an engineer and inspected by about 3 other guys before I saw it.
    > Things were so far above and beyond the NEC it was just a sight seeing
    > trip.


    Maybe it was above the NEC at the time, you should see the changes between
    1999 and 2002 editions on grounding and bonding, and ampacity.

    --
    JosephKK
    Gegen dummheit kampfen die Gotter Selbst, vergebens.  
    --Schiller
     
    joseph2k, Aug 12, 2006
    #12
  13. Aaron407

    joseph2k Guest

    Rene Tschaggelar wrote:

    > Aaron407 wrote:
    >> Hi everybody,
    >>
    >> I'm not sure if this is the right group to post this in (correct me if
    >> it's not), but I could really use some help. I'm an electrical engineer
    >> looking into lightning protection for buildings, but in my search I
    >> have found the information to be quite ambiguous as to whether
    >> lightning protection is actually mandatory or not. I am looking at a
    >> possible install on a mill building about 150' tall at a potash mine
    >> here in Saskatchewan, Canada.
    >>
    >> Could anyone direct me to any resources (American or Canadian) which
    >> state cut and dried if/when lightning protection is mandatory? I have
    >> looked through the CAN/CSA-B72-M87 and NFPA 780, but both avoid
    >> explicitly saying anything along the lines of "lightning protection is
    >> not mandatory, but highly recommended...". They use terms at the
    >> beginning like 'required', but continue with words such as
    >> 'recommended' and 'should', which have confused me to this point.
    >>
    >> Can anyone enlighten me? It would be greatly appreciated.

    >
    > Beside mandatory or not, there could be the case when
    > an insurance refuses to pay if not installed...
    >
    > Rene


    Actual legal requirements do vary some from jurisdiction to jurisdiction.
    Complying with the requirements in NFPA 70, ANSI/IEEE C2 and similar is
    often required to buy affordable insurance. I do not have my reference
    list with me.

    --
    JosephKK
    Gegen dummheit kampfen die Gotter Selbst, vergebens.  
    --Schiller
     
    joseph2k, Aug 12, 2006
    #13
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