Local AHJs here have sometimes required/accepted a single listed lug on a single pan. How you seal that effectively and permanently is a mystery to me, but what's more of a mystery is the sensibility of the conclusions they reach. Unless every pan, cap, and flashing within reach of an energized conductor is bonded using a listed lug, how would this work effectively? S-5 clamps or other attachment fasteners are probably just as effective at creating a bonding path as and roof pan fastener, but definitely can't be relied upon from a code/listing perspective. Maybe we need to encourage metal roofing manufacturers to get 2703 listing (haha - right).
Side note: I don't see AHJ's worrying about overhead service conductors potentially energizing a metal roof. I've seen some pretty shaky rusted out weatherhead pipes and downed poles in storms with overhead conductors laying on roofs. Jason Szumlanski On Mon, Jun 18, 2018 at 3:32 PM Glenn Burt <glenn.b...@glbcc.com> wrote: > 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-boun...@lists.re-wrenches.org> *On > Behalf Of *br...@willpowerelect.com > *Sent:* Monday, June 18, 2018 1:42 PM > *To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>; AE Solar < > autonomousenerg...@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 > *F:* 541.512.0061 > *E:* br...@willpowerelect.com > *W:* Willpower Electric, LLC <http://www.willpower-electric.com> > > > > *CCB **191852* > *Oregon Electrical Contractor **C681* > *NABCEP Certified Solar (PV) Installer **031409-38* > > *DUNS* *191470363* > > *Energy Trust of Oregon Trade Ally **Solar (PV) Installation & Energy > Efficient Commercial Lighting Programs * > > > > > ***This email may contain information that is privileged, confidential, or > otherwise exempt from disclosure under applicable law. If you are not the > addressee, or if it appears that you have received this email in error, > please advise me immediately by reply email, keep the contents > confidential, and immediately delete the message and any attachments from > your system. * > > > > > > -------- Original Message -------- > Subject: Re: [RE-wrenches] grounding on metal roofs > From: "glenn.b...@glbcc.com" <glenn.b...@glbcc.com> > Date: Sun, June 17, 2018 6:17 pm > To: AE Solar <autonomousenerg...@gmail.com> > Cc: RE-wrenches <re-wrenches@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.b...@glbcc.com <glenn.b...@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 KatzmanAutonomous EnergiesPO Box 1245* > > > > *Kingston, NY 12402www.autonomousenergies.com > <http://www.autonomousenergies.com>(518) 567-1468 <(518)%20567-1468>* > > > > *On Sun, Jun 17, 2018 at 1:46 PM, glenn.b...@glbcc.com > <glenn.b...@glbcc.com> <glenn.b...@glbcc.com <glenn.b...@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 KatzmanAutonomous EnergiesPO Box 1245* > > > > *Kingston, NY 12402www.autonomousenergies.com > <http://www.autonomousenergies.com>(518) 567-1468 <(518)%20567-1468>* > > > *------------------------------* > > > > > > > > > > > > > > > > *_______________________________________________List sponsored by Redwood > AllianceList Address: RE-wrenches@lists.re-wrenches.org > <RE-wrenches@lists.re-wrenches.org>Change listserver email address & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > <http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > <http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html>List > rules & etiquette:www.re-wrenches.org/etiquette.htm > <http://www.re-wrenches.org/etiquette.htm>Check out or update participant > bios:www.members.re-wrenches.org <http://www.members.re-wrenches.org>* > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > >
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