[RE-wrenches] Integrating with Lightning Protection

[Ray Walters]

I think an important point, is not to connect to their system in more 
than one place.  You don't want to create any loops that would pick up 
the induced current from a lightning strike.  We've bonded to the 
lightning rod systems at their attachment to ground.  The idea being 
that if their system takes a strike, you wouldn't want any of that 
current taking a parallel path through the solar equipment to ground.
The opposite argument is that you don't want large potential voltages 
between the array and their lightning rods in a strike.  I don't 
subscribe to this though, and think that limiting current flow through 
the equipment and then using Midnite surge suppressors to bleed voltage 
to ground is better.  Its difficult to test these theories though, so it 
begins to fall almost into the realm of religion.  None of us completely 
understand lightning.
Either way, I highly recommend bonding the grounding system to a steel 
cased well and/or the rebar in the foundation (Ufer ground)
The lower the impedance of the actual grounding electrode system, the 
better: that we can all agree on.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 6/4/2015 12:03 PM, Garrison Riegel wrote:
>
> Wrenches,
>
> Does anyone have any best practice recommendations (or books, 
> articles, etc) for integrating a roof mounted PV system with a 
> lightning protection system?  Bare #6 copper and a split bolt to the 
> braided copper connecting air terminals?  At both ends of the array?
>
> Or should we not bond these systems on the roof?  Opinions on a 2009 
> Wrenches thread varied, but I’ve heard it from a few sources that 
> these should be bonded directly.  Wondering if there is a general 
> consensus at this point?  Or strong opinions one way or the other?
>
> Thanks for your thoughts.
>
> Garrison Riegel
>
> PV Operations Manager | /Solar Service Inc/ 
> <http://www.solarserviceinc.com/>
>
> [p] 847-677-0950 | garrison at solarserviceinc.com 
> <mailto:garrison at solarserviceinc.com>
>
> NABCEP Certified PV Installation Professional™
>
>
>
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