Re: Zapping Camera Problem

[Robert Macy <robert.a.macy@xxxxxxxxx>]

On May 23, 4:38=A0am, NickMark <nmarkow...@xxxxxxxxx> wrote:
> On Thursday, May 23, 2013 6:36:32 AM UTC-4, ABLE1 wrote:
> > Hello all,
>
> > Having a problem with continued Camera location being Zapped when a sto=
rm
>
> > goes by. Over the past couple of years have had to replace a single cam=
era
>
> > location with new units after a storm. About six(6) cameras at this poi=
nt.
>
> > There are 2 cameras in this building. The other camera had been zapped =
as
>
> > well before the surge protection and ground rod was installed. Since th=
en it
>
> > just the one that has had the continued problem. The cameras are about =
40
>
> > feet apart.
>
> > The following are the other particulars.
>
> > > It has always be the video side of the camera that has been hit.
>
> > > Building is separated from main building by about 200' of underground=
 PVC
>
> > > conduit.
>
> > > Cable RG59
>
> > > Have installed at the building Ditek Surge Protector DTK-VSPBNCA. One=
 at
>
> > > each camera.
>
> > > Ground Rod installed within 50' and #12 Ground wire to Protector
>
> > > Camera Powered locally with Wall Wart 24vac
>
> > I know that this may be impossible but the main question is, what can b=
e
>
> > done to stop this from happening??
>
> > > Is there a better surge/spike protector??
>
> > > Would a second ground rod help??
>
> > > Would it make a difference if the camera was powered by 12vdc??
>
> > > Is there a way to determine the weak point of the system??
>
> > Thanks for any thoughts or suggestions that would be helpful.
>
> > Les
>
> you need to unify the grounds and tie all together =A0 a separate rod is =
causing step voltage

You can do separate ground rod *if* you configure the cabling
'correctly' [I know, sounds circular where 'correctly by definition
means it keeps on working. But, what I refer to is more like RF/
Microwave type construction techniques. For example, a connection
between two points is only a connection making the two points equal
voltage *IF* it's wider than long, else it's an inductor. An inductor
is likely to hold ALL the voltage across it for a little bit of time,
so you see, it's NOT a connection in the sense same voltage]

There are several firms that sell robust lightning protection add-
oons, but can't find fast enough.

Do you want to purchase and install, or do you want to learn a bit and
buy the bits and pieces yourself and modify the site yourself?


Here is a list of references kindly provided 2009 by Mick Matum of the
IEEE EMC group:
<http://plaza.ufl.edu/rakov/>

COPIES
2008

160. "Initial-stage pulses in upward lightning: Leader/return stroke
versus M-component mode of charge transfer to ground", Geophys. Res.
Lett., 35, L13812, doi:10.1029/2008GL034148, 2008, 5 p., D. Flache,
V.A. Rakov, F. Heidler, W. Zischank, and R. Thottappillil

156. "Influence of strike object grounding on close lightning electric
fields", J. Geophys. Res., 113, D12109, doi:10.1029/2008JD009811,
2008, 18 p., Y. Baba, and V.A. Rakov

154. "X-rays from 80-cm long sparks in air", Geophys. Res. Lett., 35,
L06805, doi:10.1029/2007GL032678, M. Rahman, V. Cooray, N.A. Ahmad, J.
Nyberg, V.A. Rakov, and S.R. Sharma

149. "Distribution of currents in the lightning protective system of a
residential building: II. Numerical modeling", IEEE Trans. on Power
Delivery, in press, L. Li and V.A. Rakov

147. "Lightning-induced currents in a buried loop conductor and a
grounded vertical conductor", IEEE Trans. on EMC, Vol. 50, No. 1,
February 2008, pp. 110-117, J. Schoene, M.A. Uman, V.A. Rakov, J.
Jerauld, B.D. Hanley, K.J. Rambo, J. Howard, and B. DeCarlo.

146. "Pulse trains characteristic of preliminary breakdown in cloud-to-
ground lightning that are not followed by return stroke pulses", J.
Geophys. Res., 113, D01102, doi:10.1029/2007JD008489, 2008, A. Nag and
V.A. Rakov

145. "Applications of Electromagnetic Models of the Lightning Return
Stroke", IEEE Trans. on Power Delivery, Vol. 23, No. 2, April 2008,
pp. 800-811, Y. Baba, and V.A. Rakov

143. "On representation of lightning return stroke as a lossy monopole
antenna with inductive loading", IEEE Trans. on EMC, Vol. 50, No. 1,
February 2008, pp. 118-127, S. Bonyadi-ram, R. Moini, S.H.H. Sadeghi,
and V.A. Rakov


2007

142. "Lightning strikes to tall objects: currents inferred from far
electromagnetic fields versus directly measured currents", Geophys.
Res. Lett., 34, L19810, doi:10.1029/2007GL030870, 2007, Y. Baba, and
V.A. Rakov

141. "Expressions for far electric fields produced at an arbitrary
altitude by lightning return strokes", J. Geophys. Res., 112, D16102,
doi:10.1029/2007JD008559, 2007, R. Thottappillil, V.A. Rakov, and N.
Theethayi

140. "Electromagnetic fields at the top of a tall building associated
with nearby lightning return strokes", IEEE Trans. on EMC, Vol. 49,
No. 3, August 2007, pp. 632-643, Y. Baba, and V.A. Rakov

139. "Insights into the ground attachment process of natural lightning
gained from an unusual triggered-lightning stroke", J. Geophys. Res.,
112, D13113, doi:10.1029/2006JD007682, 2007, J. Jerauld, M.A. Uman,
V.A. Rakov, K.J. Rambo, and G.H. Schnetzer.