I tried this once only to have the AHJ indicate that that is NOT the correct method of use for PVC conduit. "You need to have strain relief's on your wires if your using conduit". Needless to say; yes sir, removed it & used tie straps. AHJs......
-----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Richard L Ratico Sent: Monday, December 15, 2008 10:55 PM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] SS Zip Ties Fellow Wrenches, For MC cable "management", we recently used 1 1/4" Schedule 40 PVC conduit, strapped loosely (to allow for expansion/contraction) to the our top rack rail with SS pipe clamps. The conduit was drilled with a 1 1/4" hole saw every 18" or so to match the spacing of the module pigtails. The hole edges were softened with a dremel tool. The MC cables dropped into the conduit through the drilled holes. We also drilled 3/8' holes in the PVC to act as drains. Excess cable was folded and tucked into the conduit. The layout was planned to allow easy access to each module's cables. Grounding was by WEEB washers. This approach was much more satisfying and easier to implement than tywraps or clips. The conduit dropped through the roof deck through an LB in a roof boot directly into a metal junction box. EMT to the DC disco. The LB was dammed with duct seal. Best, Dick Dick Ratico Solarwind Electric Bradford, VT You wrote; Chris, I'm not saying that UV black wire ties are best. I still think that stainless cable clips made by Wiley are probably the best option of all. Wire ties, or your solution, should be used when cable clips can't work. Bill. -----Original Message----- From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Chris Worcester Sent: Friday, December 12, 2008 10:08 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] SS zip ties Hi all, We have slowly evolved into using SS hose clamps with 3/4" double wall 600V heat shrink over them to secure our wiring on our roof mount and pole mount systems. The sharp edges can turn around and bite you! The addition of heat shrink, which we buy in 4' lengths from Del City online along w/ the 10 packs of SS hose clamps, works great. We want our systems to go 30 years and plastic zip ties here in the high Sierras just don't last. It is an easy upgrade to SS zip ties and heat shrink for us. They will probably install a lot quicker. Sincerely, Chris Worcester NABCEP Certified PV Installer Phone: 530-582-4503 Fax: 530-582-4603 www.solarwindworks.com chris at solarwindworks.com "Proven Energy Solutions" -----Original Message----- From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Jeff Clearwater, Village Power Design Sent: Thursday, December 11, 2008 6:31 PM To: RE-wrenches Subject: Re: [RE-wrenches] SS zip ties Hi Bill and all, I've been searching for an alternative to plastic wire ties for some time as I'm not sure they are going to hold up over the system life of 20-30+ years and it'll be an ugly site to have all those wires drop onto the roof. But for a flush rooftop array, an assumption to replace broken ones with an O&M plan as Bill suggests is prohibitive unless you want to pull modules and rewire all over again. Way too much labor. At first I was glad to see the SS ties too - but they just don't work that well and I too worry about the sharp edges with all the contraction and expansion that goes on in an aluminum based racking system. On many commercial jobs we've used our own home made wire loom by splitting liquidtight non-metallic on a table saw. We then use a self tapper and washer to screw through the back of the inside of the split LT to the array frame and then use one-hole straps to hold the wire from coming out of the slot where we want to. I shared this method way back on this list and at http://www.home.earthlink.net/~clrwater It's code since it's outdoor rated wire anyway. I sometimes even run the LT home to a LT fitting after stopping the split (after providing a drain loop/low spot). Not exactly covered by the code but I see no inherent violation. I'm glad to see UniRac coming out with a zip bundle that slides into their rail slot but that does only some of the job as there are many places we need to attach that are not directly along their rails. I've told the folks at UniRac, DP&W, ProSolar, AEE etc. that the first racking company that comes out with an integrated loom or wire handling system will rule. That was 2 years ago. Still waiting! Thanks, Jeff Clearwater NorthEast Solar/Village Power Design _______________________________________________ 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
