[RE-wrenches] Lightning protection system

Matt Tritt solarone at charter.net
Mon Mar 9 11:04:46 PDT 2009


Hi Darryl,

Just to see what your take would be, and other's - what would the case 
be should the modules have non-conducting frames (or even no frames)is 
the case with some systems on the market?

Matt T

Darryl Thayer wrote:

>Yes the electric power and atmospheric grounding systems should be connected together to serve as a larger better grounding system.  The Electrical code requires that at only one point does the neutral (grounded) conductor of the electrical power system get connected to the grounding system, this is to prevent the grounding electrode system from carrying electrical power system currents.  The electrical power system is to be grounded to prevent the electrical power system from differentiating its self via the injection of energy from other electric power sources including atmospheric electrical energy.    
> 
>
>The lightening protection system is to create a path from the atmospheric energy to the earth grounding system.  ((Wind rain, dust and friction cause the atmosphere to become charged relative to the earth, conducting objects can build a charge if not electrically connected to the earth, these current flow all the time, although they are small sometimes, and in the case of a lightening strike incredibly large.  Even small currents can build large voltages and fail electronic components.  
>
>The frames of solar modules are electrical conduction components not normally charged that can present a personal, and physical damage potential (life-property) if they become charged by the electrical power system and therefor the underwriters require they be protected by grounding.  This accidental energy need to be safely returned to the electrical power system, and properly this is called bonding back to the neutral conductor.  This grounding is described by the NEC in 690 and 250 primarily.   The frames of the modules can become charged by atmospheric energy energy, this energy needs to be returned to the earth, via the lightening protection system, ie grounding electrode system.  The code says little about this, however, it is addressed in 690 and 250.  
>
>Sorry I said so much.
>Darryl        
>
>
>--- On Fri, 3/6/09, Drake Chamberlin <drake.chamberlin at redwoodalliance.org> wrote:
>
>  
>
>>From: Drake Chamberlin <drake.chamberlin at redwoodalliance.org>
>>Subject: Re: [RE-wrenches] Lightning protection system
>>To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
>>Date: Friday, March 6, 2009, 8:47 AM
>>I didn't get a reply to the question about connecting
>>the GEC to the 
>>lightning protection system on the 8 story building. 
>>Although this 
>>may seem like an intrinsically dangerous idea, a lightning
>>protection 
>>system is required to be bonded to the building grounding
>>electrode system.
>>
>>"250.106 Lightning Protection Systems.
>>The lightning protection system ground terminals shall be
>>bonded to 
>>the building or structure grounding electrode system."
>>
>>It would therefore seem that the suplemental ground could
>>connect to 
>>that system as well, and in fact use the existing
>>conductor.  Any 
>>input would be welcome.
>>
>>Thanks,
>>
>>Drake
>>
>>
>>
>>
>>At 09:19 PM 3/4/2009, you wrote:
>>    
>>
>>>Hello Wrenches,
>>>
>>>Can the supplemental grounding electrode conductor be
>>>      
>>>
>>connected to a 
>>    
>>
>>>lightning protection system?
>>>
>>>We have a case where it would be difficult to run a GEC
>>>      
>>>
>>down a multi 
>>    
>>
>>>story building, but have a convenient copper wire, from
>>>      
>>>
>>a lightning 
>>    
>>
>>>protection system, that runs to a rod.
>>>
>>>Thank you,
>>>
>>>Drake Chamberlin
>>>Athens Electric
>>>OH License 44810
>>>CO License 3773
>>>740-448-7328
>>>740-856-9648
>>>
>>>
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>>>
>>Drake Chamberlin
>>Athens Electric
>>OH License 44810
>>CO License 3773
>>740-448-7328
>>740-856-9648  
>>
>>
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