[RE-wrenches] grounding on metal roofs

Mon Jun 18 14:27:38 EDT 2018

NEC 250.4(A)4 Also states that normally non-current-carrying electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.

So the logic goes if an array develops a ground fault, and the faulted conductor contacts a metal roof surface, there is a possibility that the roof may become energized. So for many reasons, bond the roof to ground.

-Glenn

Renewable Energy Engineer – Cadmus

Principal Engineer – Power Guru

Principal – glb, Consulting Company

From: RE-wrenches <re-wrenches-bounces at lists.re-wrenches.org> On Behalf Of bruce at willpowerelect.com
Sent: Monday, June 18, 2018 1:42 PM
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>; AE Solar <autonomousenergies at gmail.com>
Subject: Re: [RE-wrenches] grounding on metal roofs

NEC 690.47 (A) requires the array to be grounded, not necessarily the roof. If you have bonded the rails and modules and your grounding conductor goes back to the service you should be good. 690.47 (B) allows installation of an auxiliary grounding electrode (ground rod or building steel). Not a bad idea in lightning prone areas. ;) Local AHJ may have different opinions.

Bruce Fiero-RMI

"Energizing the Rogue Valley"

4115 S Pacific Hwy

Medford, OR 97501

P: 541.535.3965
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E: bruce at willpowerelect.com <mailto:bruce at willpowerelect.com> 
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CCB 191852
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-------- Original Message --------
Subject: Re: [RE-wrenches] grounding on metal roofs
From: "glenn.burt at glbcc.com <mailto:glenn.burt at glbcc.com> " <glenn.burt at glbcc.com <mailto:glenn.burt at glbcc.com> >
Date: Sun, June 17, 2018 6:17 pm
To: AE Solar <autonomousenergies at gmail.com <mailto:autonomousenergies at gmail.com> >
Cc: RE-wrenches <re-wrenches at lists.re-wrenches.org <mailto:re-wrenches at lists.re-wrenches.org> >

Depends on the seam profile. Same device may be used in many cases. We have Also drilled and used the standard direct burial lugs on the underside of the pans, at the wave when they hang over enough to get working space. Then a horizontal run of copper wire to connect.

Don't be lulled into thinking that S-5 clamps are listed for grounding roof pans - they are not. They are only listed for module bonding to ground.

Sent from my 'smart' phone so please excuse spelling and typos.

------ Original message------

From: AE Solar

Date: Sun, Jun 17, 2018 8:46 PM

To: glenn.burt at glbcc.com <mailto:glenn.burt at glbcc.com> ;

Cc: RE-wrenches;

Subject:Re: [RE-wrenches] grounding on metal roofs

thanks glenn. and what about commercial? anyone have code references regarding grounding when doing solar on metal roofs? i thought a few years back there was a conversation on this but i can't seem to find it.

Adam Katzman
Autonomous Energies
PO Box 1245

Kingston, NY 12402
www.autonomousenergies.com <http://www.autonomousenergies.com> 
(518) 567-1468 <tel:(518)%20567-1468> 

On Sun, Jun 17, 2018 at 1:46 PM, glenn.burt at glbcc.com <mailto:glenn.burt at glbcc.com>  <glenn.burt at glbcc.com <mailto:glenn.burt at glbcc.com> > wrote:

We use the Ilsco SGB-4 ground lug on every pan under the array for residential systems.

-Glenn

Sent from my Verizon LG Smartphone

------ Original message------

From: AE Solar

Date: Sun, Jun 17, 2018 12:29 PM

To: RE-wrenches;

Cc: 

Subject:[RE-wrenches] grounding on metal roofs

wrenchers,

what methods are you all using for grounding on metal roofs? thanks

adam

Adam Katzman
Autonomous Energies
PO Box 1245

Kingston, NY 12402
www.autonomousenergies.com <http://www.autonomousenergies.com> 
(518) 567-1468 <tel:(518)%20567-1468> 

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