Re: [RE-wrenches] Oddball wire request

[Allan Sindelar]

Wrenches, What a delight to receive such a wealth of oddball solutions to my oddball request! Thank you to all who replied and all who responded. The envelope, please... And the winner is... (muffled drumroll) ... Bill Battagin! (loud applause and canned music) with his suggestion of smaller-gauge USE-2. I found 100' of 14 AWG USW-2-RHH-RHW from an online vendor in New Hampshire and ordered it. (wesbellwireandcable.com). At .160" OD, two conductors will fit inside the 3/8" CGB. First runner-up awarded to Dick Ratigo. Daryl ("Is it possible to use 1/2" carflex connectors and nm carflex from panel to panel? You could then use THWN anywhere you wanted. This is what we used to do with all our systems back in the day...."): No, unless there's a 3/8" terminal to fit 1/2" Carflex. Also, I'd need two knockouts on at least 3 of the 6 j-boxes. But thank you. Richard ("Thinking out loud here: Can you, 1) Use short pieces of the TC for the box entry /exit. Butt crimp, solder, insulate / heat shrink USE-2 or PV wire to the emerging TC tails."): Yes, that would work, just a bit laborious and inelegant. ("Or, 2) Can you modify the locknuts on the new 3/8" CGB by grinding or cutting to reduce their diameter?"): Yes, and I will, unless the six new 3/8" CGBs screw into the existing lock rings and they're still in good shape. (" Or, 3) Ditch the locknuts, use epoxy to fasten the CGB to the junction box?"): Again, it would work, but imagine the trouble my descendants would have replacing the CGBs again in another 25 years? Most likely the modules and tracker will still be working then, but what about those cracked epoxied CGBs? (tongue planted firmly in cheek while writing this...) James ("Instead of un-obtanium wire, can you glue a modern j-box onto the module, over the top of the old j-box? For example: http://www.digikey.com/product-detail/en/1986175-3/A99648-ND/1980953 Or even just an outdoor rated plastic box that has the back cut out? Dow Corning 748 Noncorrosive Silicone Sealant would be an appropriate RTV to use."): That's a really good outside-the-box solution, but it looks like I'd have to buy 35 of them, at an unknown price. J-boxes too would work but be expensive. And as a side note, all six of the original j-boxes had come loose from the Tedlar, and I glued them back on quite successfully with that silicone caulk. Mac ("What about doing splicing in the j-box with float switch cable?  Landing your home run cable to one of the panel outputs, then splicing with a return home run from your next panel?   Each conductor would function as either a series connection or a home run.  Not ideal, but seems like it will work."): Same barrier as with Daryl - I'd need two cables on at least half of the j-boxes, to handle both series and parallel wiring. Ray ("I just ran into this on a new Dasol 12 v module.  I ended up wiring with USE but couldn't do the series connections.  I had to bring each module wire into a J Box.  I'm now using Kyocera, as that was a PITA.   Since your project is low amperage, have you considered smaller USE like 12 or 14 GA?  I actually even keep 16 and 18 AWG  TC around for little modules.  The volt drop isn't as bad as you might imagine, and 18 awg actually has a free air rating of 18 amps  (crazy huh? though 240.4(D)1 limits it to 5.6 amps continuous.)"): Yep, that would work, but a lot of wiring labor (six runs of 18AWG type TC float switch cable) - as you write, a PITA - and I'd worry about the additional voltage drop (0.4V, 2.7% VD) on average of 8' of 18 AWG at 3A and 14V. At 28V and 14 AWG, VD is 0.6% for the same length. Mick: ("Think back to the old Siemens M-53 which also had a tiny j-box. That box had orange spongies through which one would poke a #10 USE-2 wire, then an automotive style e-clip was pressed onto the wire insulation for strain relief. As a variation on that theme, I might try using my butane Master Ultratorch with soldering tip installed. Being careful of how the exhaust jet is pointing I would use the solder tip to melt a right sized hole in the Solec j-box, then either the e-clip method could provide strain relief by bearing against the inside surface of the box, OR:Tiny zip ties could do a similar trick to make the wire too fat to pull back through the melted hole. I'd use the black UV ties, put one on the inside of the box and one on the outside so the wire couldn't move either direction, then...since even those UV ties get brittle out here, cover the outer one with black RTV silicone."): Yep, that would work too. I might try a drill before a torch, though. What a wealth of knowledge! Allan Allan Sindelar al...@positiveenergysolar.com NABCEP Certified PV Installation Professional NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder, Positive Energy, Inc. A Certified B CorporationTM 3209 Richards Lane Santa Fe, New Mexico 87507 505 424-1112 office 780-2738 cell www.positiveenergysolar.com On 10/9/2013 11:48 PM, Allan Sindelar wrote: Wrenches, I do a fair amount of work on ancient systems, just because there's been off grid here for decades. I'm rewiring several old arrays for my next door (meaning < 1/4 mile away) neighbor. The particular array has six 53W Solec modules wired as three two-module 24V pairs, on a Zomeworks tracker so old that it has aluminum rails and attached freon canisters instead of the integral square tubes. Both modules and tracker continue to work well, but the wiring is so degraded from sun exposure that's it's bare in spots, and this is what I want to fix. Each module has a tiny j-box - 3" x 3" x 7/8" deep. Each j-box has a single 3/8" cord grip bushing (CGB). Each bushing has two #10 conductors coming out of the single hole in the CGB. The O.D. of each wire is about the same as that of THWN. The problem is that the single hole in the CGB is only large enough to fit this diameter. USE-2 is too large, and modern PV wire is way too large. I bought a dozen replacement 3/8" CGBs from Del City, but the matching lock rings are too large to fit inside the j-boxes. I'd be cautious about using a narrow Unibit to drill an additional hole in each j-box anyway, given that the holes would be so close to the backsheet. The easiest solution would be to find some sunlight-resistant, wet-rated single-conductor wire in #10 or #12 that has an insulation O.D. about the same as THHN/THWN. Any ideas, please? Code is not an issue in this instance - I just want a solution that works. I thought about using float switch cable, which is UV-resistant, wet-rated, direct-burial-rated type TC. We keep plenty in stock for signal circuits, and it fits and is strong. The problem is that I need single conductors, because each module will have one series conductor and one output conductor, and they run to different locations. Are there any better ideas out there? Thanks, Allan -- Allan Sindelar al...@positiveenergysolar.com NABCEP Certified PV Installation Professional NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder, Positive Energy, Inc. A Certified B CorporationTM 3209 Richards Lane Santa Fe, New Mexico 87507 505 424-1112 office 780-2738 cell www.positiveenergysolar.com

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