That’s why we use the Ufer, our AHJ assumes that once a layer of rust develops this is not valid...........
Dana Orzel Great Solar Works, Inc. C - 208.721.7003 [email protected] Idaho Contractor - # 028765 Idaho PV # 028374 NABCEP # 051112-136 www.greatsolarworks.com "Responsible Technologies for Responsible People since 1988" Please consider the environment before printing this email. -----Original Message----- From: RE-wrenches <[email protected]> On Behalf Of Ray Sent: Thursday, June 24, 2021 4:51 PM To: [email protected] Subject: Re: [RE-wrenches] Grounding Top of Pole Mount Array with a Ufer We always put our assumption in our plan notes, based on our interpretation of 250.52(A)(7). AHJs have never questioned it, and we also tie the pole to any rebar, so its all one big happy grounding electrode. Ray Walters Remote Solar 303 505-8760 On 6/24/21 6:49 PM, frenergy wrote: > Ray, > > I couldn't agree more, its been my experience over the > years that using 20 feet of #4 rebar in a building's footing was > kosher and accepted NEC 250.52(3). There's a heck of a lot more > surface area in 8" pipe 5-6 feet into the earth than rebar in a > foundation footing. The ground at the bottom of the pole footing is > also more likely to be damper. Our AHJ has always accepted the steel > pole as a ground rod....common sense prevails sometimes. > > Bill > > Feather River Solar Electric > Bill Battagin, Owner > 4291 Nelson St. > Taylorsville, CA 95983 > 530.284.7849 > CA Lic 874049 > www.frenergy.net > > On 6/24/2021 7:31 AM, Ray wrote: >> Usually a steel pole in concrete has enough surface area to qualify >> as a plate electrode under 250.52(A)(7). It needs to be at least 2 >> sq ft and 1/4" thick, and have an electrically conductive surface. So >> we just drill and tap our ground connection into the pole, near the >> combiner box. >> >> Ray Walters >> Remote Solar >> 303 505-8760 >> >> On 6/24/21 8:16 AM, Dana Orzel wrote: >>> For all of our free standing arrays we now use a Ufer clamp to the >>> rebar either cage or just anti spin rebar that is welded to the pole >>> in the concrete, with #4 braided copper up to the pole combiner box, >>> inverter, etc. for our ground. >>> With a pole mount & a concrete base it is way easier & less >>> expensive than a ground rod, & the inspector seems happier with this >>> approach. >>> >>> >>> >>> Dana Orzel Great Solar Works, Inc. >>> C - 208.721.7003 [email protected] Idaho >>> Contractor - # 028765 Idaho PV # 028374 NABCEP # 051112-136 >>> www.greatsolarworks.com "Responsible Technologies for Responsible >>> People since 1988" >>> Please consider the environment before printing this email. >>> >>> >>> -----Original Message----- >>> From: RE-wrenches <[email protected]> On >>> Behalf Of [email protected] >>> Sent: Wednesday, June 23, 2021 9:33 PM >>> To: RE-wrenches <[email protected]> >>> Subject: Re: [RE-wrenches] Top of Pole Mount Array on Ledge >>> >>> Ben, >>> There is a way if the ledge is solid and true. Twice I have done the >>> following with ledge at 18” to 24” below grade. Excavate down to >>> ledge, drill down into the ledge and you will determine the >>> suitability of the following method. Drill for a pattern of many >>> rebar penetrations in to the ledge. Drill to a reasonable depth (as >>> deep into the ledge as you are able) in my case it was based on our >>> drilling tool and bit length capabilities. We used a large sono >>> tube. 42” as a recall, both of these jobs were over 12 years ago and >>> my recall on the exact size may be off. >>> Determine the best adhesive product to use in your drilled holes for >>> the rebar, again my memory fails as to what we used based on >>> recommendation from a local civil engineer. The sono tube height >>> above grade was determined to be 2’ for one TPM12 and 3.5’ above >>> grade for a TPM16. Depth down to the ledge determines how high above >>> grade you need the concrete footing/base. Use rebar lengths that >>> will end a few inches below the finished surface. For grounding you >>> can coil up ground wire and lay it on the surface of the ledge >>> before your concrete pour. I ran the ground wire through a short >>> length of 1/2” or 3/4” PVC conduit, to protect the copper ground >>> wire where it comes out of the concrete. Place the conduit coming >>> out of the concrete with the ground wire just to the side of where >>> the mounting plate base for the TPM will be and fill the PVC conduit >>> with a good caulk sealer to keep air and water out of this hole as a >>> nexus of concrete, and air will corrode the copper. The TPM’s for >>> those two jobs were made of 8” SCHD 80 steel, we had a large plate >>> welded to the bottom with 4 vertical side supports on the pipe up >>> about a foot. Place the appropriate sized anchor bolts in the >>> concrete pour to match your TPM base. Both of these TPM’s have >>> worked out well over the years. Local conditions will determine the >>> suitability of this method. >>> >>> >>> Sent from my iPhone > > _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. 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