Re: [RE-wrenches] AL wire with DC
I used to have a customer who direct buried his own AL wire with a trencher, no sand or conduit for about 600' several years ago. It failed and now I am the bad guy, it is amazing how many people he has told that I did it. Lessons learned, avoid aluminum, use conduit and don't let the customer do it. I also have seen romex buried with a shovel tip 2 below the surface. Just another experience for the mental file cabinet. Later, Bob Ellison From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Nick Soleil Sent: Thursday, July 29, 2010 2:16 AM To: RE-wrenches Subject: Re: [RE-wrenches] AL wire with DC One of our installers put a shovel through a length of romex underground today? Not even direct burial wire! Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 _ From: Jeff Oldham starpowe...@juno.com To: re-wrenches@lists.re-wrenches.org Sent: Wed, July 28, 2010 1:31:16 PM Subject: Re: [RE-wrenches] AL wire with DC IMHO one should never ever direct bury ANY class of wire, it can be a very expensive gamble making the cost of your conduit insurance policy an absolute bargain. This is one of the DIY'ers #1 mistake in UG wire runs. From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions http://thirdpartyoffers.juno.com/TGL3132/4c5093aa196624f4bf8st02vuc Penny Stock Soaring 3000% Sign up for Free to find out what the next 3000% Stock Winner Is! http://thirdpartyoffers.juno.com/TGL3132/4c5093aa196624f4bf8st02vuc PennyStocksUniverse.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
Re: [RE-wrenches] AL wire with DC
IMHO one should never ever direct bury ANY class of wire, it can be a very expensive gamble making the cost of your conduit insurance policy an absolute bargain. This is one of the DIY'ers #1 mistake in UG wire runs. From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions Penny Stock Soaring 3000% Sign up for Free to find out what the next 3000% Stock Winner Is! http://thirdpartyoffers.juno.com/TGL3131/4c5093aa196624f4bf8st02vuc___ 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] AL wire with DC
The insulation on Al cable rated for direct burial is thick and tough. But, DON'T direct bury it. Carefully pull it into correctly installed PVC conduit. Use marker tape above the conduit, just below grade. If you're in an area that doesn't experience ground frost, MAYBE, VERY CAREFULLY, plant the cable in a generous amount of sand. If you're in an region with frost, ALWAYS use conduit. I think it is false economy to skip the conduit. The sand application is very time consuming. Buried copper wire with nicked insulation may not turn to dust, but is certainly a MAJOR bummer, particularly if it's not in conduit, AND, it's at least 3X the cost of Al. Al, done right, no worries. Dick Ratico Solarwind Electric --- Drake wrote: Aluminum wire got its bad name during the era when it was use in 15 and 20 amp circuits, with #12 and #10 wire. That stuff is a nightmare. As an electrician that has cleaned up some of the messes, I can supply ample horror stories. #2 and larger sizes of AL work fine. It is important to use antioxidant on the connections. Separate copper wire from aluminum using a listed splicing device. Aluminum wire will turn to white powder in an underground cable where the insulation has been breached. This is true for DC or AC. At 05:51 PM 7/26/2010, Jeff wrote: I have used AL wire in DC circuits for 30 years and have never had a problem. If you carefully follow the protocols for working with AL you should have the same experience. As pointed out the cost difference can be staggering. I'm designing an o-t-g 3kW PV system now that has this array 1300' from the batteries, AL is the only reasonable answer. From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions --- end of quote --- ___ 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] AL wire with DC
Agreed with Dick on this one. First, if you are going the DB route, then you have to get it down at least 24 instead of 18. No problem some places, a HUGE problem others. Then there are the burrowing critters like ground squirrels which love to chew on anything. I have heard that there is something put into the insulation which makes it distasteful, but I sure don't believe it- if true. Bob-O On Jul 27, 2010, at 4:06 AM, Richard L Ratico wrote: The insulation on Al cable rated for direct burial is thick and tough. But, DON'T direct bury it. Carefully pull it into correctly installed PVC conduit. Use marker tape above the conduit, just below grade. If you're in an area that doesn't experience ground frost, MAYBE, VERY CAREFULLY, plant the cable in a generous amount of sand. If you're in an region with frost, ALWAYS use conduit. I think it is false economy to skip the conduit. The sand application is very time consuming. Buried copper wire with nicked insulation may not turn to dust, but is certainly a MAJOR bummer, particularly if it's not in conduit, AND, it's at least 3X the cost of Al. Al, done right, no worries. Dick Ratico Solarwind Electric --- Drake wrote: Aluminum wire got its bad name during the era when it was use in 15 and 20 amp circuits, with #12 and #10 wire. That stuff is a nightmare. As an electrician that has cleaned up some of the messes, I can supply ample horror stories. #2 and larger sizes of AL work fine. It is important to use antioxidant on the connections. Separate copper wire from aluminum using a listed splicing device. Aluminum wire will turn to white powder in an underground cable where the insulation has been breached. This is true for DC or AC. ___ 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] AL wire with DC
I have used AL wire in DC circuits for 30 years and have never had a problem. If you carefully follow the protocols for working with AL you should have the same experience. As pointed out the cost difference can be staggering. I'm designing an o-t-g 3kW PV system now that has this array 1300' from the batteries, AL is the only reasonable answer. From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions SHOCKING: 2010 Honda Civic for $1,732.09 SPECIAL REPORT: High ticket items are being auctioned for an incredible 90% off! http://thirdpartyoffers.juno.com/TGL3131/4c4e03bf90d8b9f2c2st05vuc___ 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] AL wire with DC
Aluminum wire got its bad name during the era when it was use in 15 and 20 amp circuits, with #12 and #10 wire. That stuff is a nightmare. As an electrician that has cleaned up some of the messes, I can supply ample horror stories. #2 and larger sizes of AL work fine. It is important to use antioxidant on the connections. Separate copper wire from aluminum using a listed splicing device. Aluminum wire will turn to white powder in an underground cable where the insulation has been breached. This is true for DC or AC. At 05:51 PM 7/26/2010, you wrote: I have used AL wire in DC circuits for 30 years and have never had a problem. If you carefully follow the protocols for working with AL you should have the same experience. As pointed out the cost difference can be staggering. I'm designing an o-t-g 3kW PV system now that has this array 1300' from the batteries, AL is the only reasonable answer. From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative SOLutions http://thirdpartyoffers.juno.com/TGL3132/4c4e03bf90d8b9f2c2st05vucSHOCKING: 2010 Honda Civic for $1,732.09 http://thirdpartyoffers.juno.com/TGL3132/4c4e03bf90d8b9f2c2st05vucSPECIAL REPORT: High ticket items are being auctioned for an incredible 90% off! http://thirdpartyoffers.juno.com/TGL3132/4c4e03bf90d8b9f2c2st05vucctips.net ___ 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 Drake Chamberlin Athens Electric OH License 44810 CO License 3773 NABCEP TM Certified PV Installer Office - 740-448-7328 Mobile - 740-856-9648 ___ 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] AL wire with DC
Dana, Thanks for the input. Excuse me please, OG jobs are? If the wire had been copper and didn't melt, but instead continued to arc, would the resultant heat have eventually started a fire? What type of splice was it? Does no one else use Al for DC? Here in rocky Vermont/NH, we use the same type aluminum URD cable for both AC and DC runs, but, always installed in PVC conduit, never direct buried. Haven't seen seen a problem yet. Dick Ratico Solarwind Electric --- You wrote: The problem with Al is that, IF there is ever a loose connection, associated arcing, that it melts not like copper in the same situation which may arc but not melt. I have come in on OG jobs where Al was employed and found J boxes that were [sometimes wet] and had loose connections and the splice was charred/melted and the AL wire was not conducting melted beyond use, directly at the splice. The rubber linemen's tape was charred and there was a direct short to the metal box which was at least grounded correctly. I tend not to use Al based on this experience. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray Walters Sent: Friday, July 23, 2010 7:46 AM To: RE-wrenches Subject: Re: [RE-wrenches] calculating DC voltage drop I try to keep it in copper for DC, as I had always heard of trouble with Aluminum on DC. (True or Old Wrenches Tale?) We definitely go to Al on long AC runs, as its whats available, and the cost difference becomes remarkable. I've seen small cuts in Al, later corrode completely through the conductor.(AC run) I'm not sure what would happen it were DC. Probably depend on whether it was positive or negative, and which was bonded to ground? (either accelerate the corrosion, or act as cathodic protection?) R. Walters r...@solarray.com Solar Engineer --- end of quote --- ___ 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] AL wire with DC
OG - Off Grid Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 -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: Friday, July 23, 2010 4:18 PM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] AL wire with DC Dana, Thanks for the input. Excuse me please, OG jobs are? If the wire had been copper and didn't melt, but instead continued to arc, would the resultant heat have eventually started a fire? What type of splice was it? Does no one else use Al for DC? Here in rocky Vermont/NH, we use the same type aluminum URD cable for both AC and DC runs, but, always installed in PVC conduit, never direct buried. Haven't seen seen a problem yet. Dick Ratico Solarwind Electric --- You wrote: The problem with Al is that, IF there is ever a loose connection, associated arcing, that it melts not like copper in the same situation which may arc but not melt. I have come in on OG jobs where Al was employed and found J boxes that were [sometimes wet] and had loose connections and the splice was charred/melted and the AL wire was not conducting melted beyond use, directly at the splice. The rubber linemen's tape was charred and there was a direct short to the metal box which was at least grounded correctly. I tend not to use Al based on this experience. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray Walters Sent: Friday, July 23, 2010 7:46 AM To: RE-wrenches Subject: Re: [RE-wrenches] calculating DC voltage drop I try to keep it in copper for DC, as I had always heard of trouble with Aluminum on DC. (True or Old Wrenches Tale?) We definitely go to Al on long AC runs, as its whats available, and the cost difference becomes remarkable. I've seen small cuts in Al, later corrode completely through the conductor.(AC run) I'm not sure what would happen it were DC. Probably depend on whether it was positive or negative, and which was bonded to ground? (either accelerate the corrosion, or act as cathodic protection?) R. Walters r...@solarray.com Solar Engineer --- end of quote --- ___ 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-wren ches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrench es.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.851 / Virus Database: 271.1.1/3023 - Release Date: 07/23/10 00:36:00 ___ 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] AL wire with DC
I'm with Dick on this one... Sure, I've seen a few good oopsies involving aluminum, (where the J box does the Salvador Dali thing)... but they're usually installed by "Uncle Larry" types... as long as the install is code compliant (Listed and properly installed), I don't think it maters much. dbDan BrownFoxfire Energy Corp.Renewable Energy Systems(802)-483-2564www.Foxfire-Energy.comNABCEP #092907-44 Original Message Subject: Re: [RE-wrenches] AL wire with DC From: richard.l.rat...@valley.net (Richard L Ratico) Date: Fri, July 23, 2010 6:18 pm To: re-wrenches@lists.re-wrenches.org Dana, Thanks for the input. Excuse me please, "OG jobs" are? If the wire had been copper and didn't melt, but instead continued to arc, would the resultant heat have eventually started a fire? What type of splice was it? Does no one else use Al for DC? Here in rocky Vermont/NH, we use the same type aluminum URD cable for both AC and DC runs, but, always installed in PVC conduit, never direct buried. Haven't seen seen a problem yet. Dick Ratico Solarwind Electric --- You wrote: The problem with Al is that, IF there is ever a loose connection, associated arcing, that it melts not like copper in the same situation which may arc but not melt. I have come in on OG jobs where Al was employed and found J boxes that were [sometimes wet] and had loose connections and the splice was charred/melted and the AL wire was not conducting melted beyond use, directly at the splice. The rubber linemen's tape was charred and there was a direct short to the metal box which was at least grounded correctly. I tend not to use Al based on this experience. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com "Responsible Technologies for Responsible People since 1988" -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray Walters Sent: Friday, July 23, 2010 7:46 AM To: RE-wrenches Subject: Re: [RE-wrenches] calculating DC voltage drop I try to keep it in copper for DC, as I had always heard of trouble with Aluminum on DC. (True or Old Wrenches Tale?) We definitely go to Al on long AC runs, as its whats available, and the cost difference becomes remarkable. I've seen small cuts in Al, later corrode completely through the conductor.(AC run) I'm not sure what would happen it were DC. Probably depend on whether it was positive or negative, and which was bonded to ground? (either accelerate the corrosion, or act as cathodic protection?) R. Walters r...@solarray.com Solar Engineer --- end of quote --- ___ 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] AL wire with DC
check out NEC 110.14Dan BrownFoxfire Energy Corp.Renewable Energy Systems(802)-483-2564www.Foxfire-Energy.comNABCEP #092907-44 Original Message Subject: [RE-wrenches] AL wire with DC From: "Dana" d...@solarwork.com Date: Fri, July 23, 2010 6:54 pm To: "'RE-wrenches'" re-wrenches@lists.re-wrenches.org I cannot speak for what if. I have seen CU AL bolted in AL mechanical butt splices where someone did not torque it to spec. and it went to arcing. Both were a mess ; The butt splice was pitted / damaged and needed replacement, the AL cable melted and the copper cable did not. It the same amperage, but both were 1,600+watt arrays. But AL is softer and the strands are larger for the same size as CU wire. I think that there was a greater safety factor in the CU. More strands, finer wires, a harder metal, therefore greater contact area on the AL mechanical butt splice. I have seen split bolts that were loose and you could pull the wire out easily and no melting or arcing. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com "Responsible Technologies for Responsible People since 1988" -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Dana Sent: Friday, July 23, 2010 4:24 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] AL wire with DC OG - Off Grid Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com "Responsible Technologies for Responsible People since 1988" -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: Friday, July 23, 2010 4:18 PM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] AL wire with DC Dana, Thanks for the input. Excuse me please, "OG jobs" are? If the wire had been copper and didn't melt, but instead continued to arc, would the resultant heat have eventually started a fire? What type of splice was it? Does no one else use Al for DC? Here in rocky Vermont/NH, we use the same type aluminum URD cable for both AC and DC runs, but, always installed in PVC conduit, never direct buried. Haven't seen seen a problem yet. Dick Ratico Solarwind Electric --- You wrote: The problem with Al is that, IF there is ever a loose connection, associated arcing, that it melts not like copper in the same situation which may arc but not melt. I have come in on OG jobs where Al was employed and found J boxes that were [sometimes wet] and had loose connections and the splice was charred/melted and the AL wire was not conducting melted beyond use, directly at the splice. The rubber linemen's tape was charred and there was a direct short to the metal box which was at least grounded correctly. I tend not to use Al based on this experience. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com "Responsible Technologies for Responsible People since 1988" -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray Walters Sent: Friday, July 23, 2010 7:46 AM To: RE-wrenches Subject: Re: [RE-wrenches] calculating DC voltage drop I try to keep it in copper for DC, as I had always heard of trouble with Aluminum on DC. (True or Old Wrenches Tale?) We definitely go to Al on long AC runs, as its whats available, and the cost difference becomes remarkable. I've seen small cuts in Al, later corrode completely through the conductor.(AC run) I'm not sure what would happen it were DC. Probably depend on whether it was positive or negative, and which was bonded to ground? (either accelerate the corrosion, or act as cathodic protection?) R. Walters r...@solarray.com Solar Engineer --- end of quote --- ___ 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-wren ches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrench es.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.851 / Virus Database: 271.1.1/3023 - Release Date: 07/23/10 00:36:00 ___ 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-wren ches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrench es.org List ru
Re: [RE-wrenches] AL wire with DC
I think some of the advantage of the Cu in a bad connection is that it dissipates heat better. That might explain the melting Al, but not the Cu. Cu will melt and cook the insulation if the connection is loose enough at high enough amperage. Again, I have not personally seen a problem with Al on DC runs, I just haven't done it. 110.14 just specifies what we already know( I think), that you have to use special connectors that isolate the cu from direct contact with the Al. The new splice block type connectors are great for this. R. Walters r...@solarray.com Solar Engineer On Jul 23, 2010, at 4:54 PM, Dana wrote: I cannot speak for what if. I have seen CU AL bolted in AL mechanical butt splices where someone did not torque it to spec. and it went to arcing. Both were a mess ; The butt splice was pitted / damaged and needed replacement, the AL cable melted and the copper cable did not. It the same amperage, but both were 1,600+watt arrays. But AL is softer and the strands are larger for the same size as CU wire. I think that there was a greater safety factor in the CU. More strands, finer wires, a harder metal, therefore greater contact area on the AL mechanical butt splice. I have seen split bolts that were loose and you could pull the wire out easily and no melting or arcing. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Dana Sent: Friday, July 23, 2010 4:24 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] AL wire with DC OG - Off Grid Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 -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: Friday, July 23, 2010 4:18 PM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] AL wire with DC Dana, Thanks for the input. Excuse me please, OG jobs are? If the wire had been copper and didn't melt, but instead continued to arc, would the resultant heat have eventually started a fire? What type of splice was it? Does no one else use Al for DC? Here in rocky Vermont/NH, we use the same type aluminum URD cable for both AC and DC runs, but, always installed in PVC conduit, never direct buried. Haven't seen seen a problem yet. Dick Ratico Solarwind Electric --- You wrote: The problem with Al is that, IF there is ever a loose connection, associated arcing, that it melts not like copper in the same situation which may arc but not melt. I have come in on OG jobs where Al was employed and found J boxes that were [sometimes wet] and had loose connections and the splice was charred/melted and the AL wire was not conducting melted beyond use, directly at the splice. The rubber linemen's tape was charred and there was a direct short to the metal box which was at least grounded correctly. I tend not to use Al based on this experience. Thanks, Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray Walters Sent: Friday, July 23, 2010 7:46 AM To: RE-wrenches Subject: Re: [RE-wrenches] calculating DC voltage drop I try to keep it in copper for DC, as I had always heard of trouble with Aluminum on DC. (True or Old Wrenches Tale?) We definitely go to Al on long AC runs, as its whats available, and the cost difference becomes remarkable. I've seen small cuts in Al, later corrode completely through the conductor.(AC run) I'm not sure what would happen it were DC. Probably depend on whether it was positive or negative, and which was bonded to ground? (either accelerate the corrosion, or act as cathodic protection?) R. Walters r...@solarray.com Solar Engineer --- end of quote --- ___ 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-wren ches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrench es.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.851
