Re: [RE-wrenches] helical screw piers
Wrenches, We used a company called techno Metal Post ( www.technometalpost.com ) I believe it is a franchise arrangement with the main company in Canada. Here is a business opportunity if a franchise does not exist in your community. They are screwed into the ground while hydraulic pressure is applied. We received a stamped engineering report after completion that identified how many posts were set, to what depth and how much hydraulic pressure had been applied for load bearing capacity It requires a special unit designed for this purpose We set 8 posts in 2 rows of 4 and then attached a UniRac U-LA Ground Mount racking system for 28 Sanyo 200's The posts in this case were 2 schedule 40 galvanized steel pipe ready for the UniRac mounting system They also shot the elevation and cut each pipe to the proper height so that the relationship between the front row of pipes and the back row of pipes was set to receive the racking system and then the mounting rails would be at latitude for this site. We supplied the heights that were required. Many other uses for these screw piers. Pictures on their website Larry On Jan 26, 2009, at 1:48 AM, ASAP POWER! 2 wrote: Sounds like we gots to have it. Larry, any pics? If I assume correctly, these are literally screwing into the ground in place of a concrete footing. such that you can place/attach a structural or pipe column or its part of the screw. I can call some local rental yards and do some internet searching, but is there a brand name to the screw, driver, or a specialized 4WD unit? How many did you drive for 5.6kW? I had contacted the outfit that advertised on TV/web for a while a couple of years ago, but wasn't impressed, however, thought maybe with the right soil it could be exceptional tool for quick guy wire anchoring purposes for wind towers. This sounds like something more substantial. Thanks, Peter D. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches- boun...@lists.re-wrenches.org] On Behalf Of Larry Brown Sent: Sunday, January 25, 2009 5:58 PM To: RE-wrenches Subject: Re: [RE-wrenches] helical screw piers Eric, We just used helical screw piers on a 5.6kw ground mount The site was difficult due to its slope and soft because the frost had come back out after some warm days There was an excellent chance that a concrete truck would have gotten stuck and a back hoe would have made a mess The 4 wheel drive unit that drives the helical screw piers had no trouble navigating the terrain, did no damage to the site, was in and out in less than a day. The piers were in two parallel rows and all were within 1/2 of our string, though that is in the skill of the operator In very rocky soil it might be more problematic Larry Brown Sun Mountain On Jan 25, 2009, at 8:05 PM, Eric Andrews wrote: Does anyone have any experience using Helical screw pier footing for ground mount racks? Eric ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches- re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re- wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] helical screw piers
Ken, We have done a lot of ground mounts We usually do an excavation at least to frost depth, 4 feet here, and then use either sonotubes or big foot tubes if the ground is wet, set on a couple of inches of gravel. We then set a 2 schedule 40 galvanized steel pipe, that has been drilled near the bottom and a 6 piece of rebar fastened to prevent twisting and pull out, in each form and build a wooden frame around the steel to keep them plumb, square and in alignment. Then we pour concrete and often get charged extra for a small load of concrete. We come back and strip the wooden framework and hand grade what the back hoe was not able to finish. With the screw piers it was just myself and the equipment operator. No damage to the site. Ready to go the next day with the mounting racks They charged us $250 per post, labor and material and engineering. If we had 20 or 30 posts to set it would either be a negotiated price for the whole job or a careful calculation as to the least expensive option Larry On Jan 26, 2009, at 7:40 AM, Ken Schaal wrote: Would you be able to show the cost for those 8 piers?? Did you do some estimates for pole mounts or concrete pier mounts?? Thanks Ken - Original Message - From: Larry Brown To: i...@asappower.com ; RE-wrenches Sent: Monday, January 26, 2009 7:24 AM Subject: Re: [RE-wrenches] helical screw piers Wrenches, We used a company called techno Metal Post ( www.technometalpost.com ) I believe it is a franchise arrangement with the main company in Canada. Here is a business opportunity if a franchise does not exist in your community. They are screwed into the ground while hydraulic pressure is applied. We received a stamped engineering report after completion that identified how many posts were set, to what depth and how much hydraulic pressure had been applied for load bearing capacity It requires a special unit designed for this purpose We set 8 posts in 2 rows of 4 and then attached a UniRac U-LA Ground Mount racking system for 28 Sanyo 200's The posts in this case were 2 schedule 40 galvanized steel pipe ready for the UniRac mounting system They also shot the elevation and cut each pipe to the proper height so that the relationship between the front row of pipes and the back row of pipes was set to receive the racking system and then the mounting rails would be at latitude for this site. We supplied the heights that were required. Many other uses for these screw piers. Pictures on their website Larry On Jan 26, 2009, at 1:48 AM, ASAP POWER! 2 wrote: Sounds like we gots to have it. Larry, any pics? If I assume correctly, these are literally screwing into the ground in place of a concrete footing. such that you can place/attach a structural or pipe column or its part of the screw. I can call some local rental yards and do some internet searching, but is there a brand name to the screw, driver, or a specialized 4WD unit? How many did you drive for 5.6kW? I had contacted the outfit that advertised on TV/web for a while a couple of years ago, but wasn't impressed, however, thought maybe with the right soil it could be exceptional tool for quick guy wire anchoring purposes for wind towers. This sounds like something more substantial. Thanks, Peter D. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re- wrenches-boun...@lists.re-wrenches.org] On Behalf Of Larry Brown Sent: Sunday, January 25, 2009 5:58 PM To: RE-wrenches Subject: Re: [RE-wrenches] helical screw piers Eric, We just used helical screw piers on a 5.6kw ground mount The site was difficult due to its slope and soft because the frost had come back out after some warm days There was an excellent chance that a concrete truck would have gotten stuck and a back hoe would have made a mess The 4 wheel drive unit that drives the helical screw piers had no trouble navigating the terrain, did no damage to the site, was in and out in less than a day. The piers were in two parallel rows and all were within 1/2 of our string, though that is in the skill of the operator In very rocky soil it might be more problematic Larry Brown Sun Mountain On Jan 25, 2009, at 8:05 PM, Eric Andrews wrote: Does anyone have any experience using Helical screw pier footing for ground mount racks? Eric ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches- re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings:
[RE-wrenches] Galvanic compatibility of commonly used solar materials
Hi Wrenches, I'm wondering what types of experiences you folks have with galvanic corrosion. As we all know, racking and ground systems commonly use copper, aluminum, steel, etc. which may or may not be compatible with each other. There's the theory: http://www.engineersedge.com/galvanic_capatability.htm and then there's real life experience. I have first hand experience with aluminum lay in lugs used to bond modules corroding and turning to powder. We all know to use tin coated copper lugs for module and racking grounding. However, I see bare copper ground wires run over all sorts of different metals and I wonder what issues might pop up in the long haul. How well does bare copper hold up when it is touching anodized aluminum? What about copper and hot dipped strut? How do you run bare ground wire when you're connecting multiple arrays separated from each other? Has anyone seen issues arising between steel and aluminum racking parts? I'm looking forward to seeing what types of field experiences you have seen. Best, August August Goers Luminalt Energy Corporation O: 415.564.7652 M: 415.559.1525 F: 650.244.9167 www.luminalt.com aug...@luminalt.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
