We have standardized on DC markings White negative and Red positive. Chris Mason Comet Systems Anguilla (264) 235-5670 St. Kitts (869) 662-5670 skype netconcepts
NABCEP Certified Solar PV Installerâ„¢ Renewable Energy Systems professional Generac Generators Factory technician On Jun 29, 2013 8:30 PM, "David Katz" <dk...@aeesolar.com> wrote: > Watch out for accountants who become installers. They always thing red > negative and black positive. > David Katz > > Sent from my iPhone > > On Jun 28, 2013, at 5:40 PM, "Ray Walters" <r...@solarray.com> wrote: > > > Richard, when you use your Fluke 87 to measure Vdc, black is negative, > > red is positive. The black is labeled common because the meter can also > > be used for current measurements. (I have a Fluke 89) > > When you start using black wire for positive, it may be allowed by code, > > but there just isn't a good reason for it. > > Its just too easy to make a mistake, and its just too easy to adhere to > > the multimeter convention and keep it safer. > > > > I have personally watched seasoned electricians argue color coding with > > me, then minutes later get mixed up and wire two 10 module strings in > > series, because they forgot for a moment that they were working on a > > positive grounded system. The result was an almost 1000 v arc that > > jumped an opened fuse holder (only rated to 600 vdc) and started a small > > fire in the inverter, before I disconnected it at the array. > > > > Please give one example where leaving positive unmarked with black wire > > makes more sense than taping it. Colored electrical tape, and label > > tape are much cheaper than inverters and people. THHN, USE, and PV wire > > can all be purchased in red, white, and black. (which saves time with > > multiple home runs) > > Its not code yet, but it's good sense, all the way back to the color > > coded jumper cables you might have in your trunk. > > I have discussed this with many electricians over the years, but > > eventually every single one sees that's its really easy, no cost, and > > still code compliant to make things safer. > > > > R.Ray Walters > > CTO, Solarray, Inc > > Nabcep Certified PV Installer, > > Licensed Master Electrician > > Solar Design Engineer > > 303 505-8760 > > > > On 6/28/2013 2:49 PM, Richard L Ratico wrote: > >> Respectfully: > >> My Fluke 87 does not use this convention. Black is labeled the COMMON > terminal, > >> the red terminal is labeled according to function, not polarity. > Battery based > >> inverter manus. using this convention typically provide BOS enclosures > with OCP > >> for only one inverter conductor. This requires the other conductor to be > >> grounded and colored white or gray. Therefore IMHO the manus. should > use only + > >> or - to identify inverter terminals. Many, if not most, battery > companies do > >> this already. Mr. Wiles is, of course, welcome to his opinion. > >> > >> I would suggest we stay with the NEC required use of any color other > than white, > >> green or gray for ungrounded conductors. This gives installers some > flexibility. > >> It also encourages the guy on the hot roof or the gal in the stuffy > mechanical > >> room to check and double check, maybe triple check polarity, as they > should be > >> doing anyway. I do like the practice of enhanced identification of > conductors in > >> positive ground systems. > >> > >> Dick Ratico > >> Solarwind Electric > >> > >> > >> --- You wrote: > >> The convention of red for positive and black for negative is not just > >> automotive. It is also used by all battery based inverter manus, all > >> battery companies, and all multimeters. > >> John Wiles also agrees; > >> red = positive, black = negative for ungrounded systems > >> red = positive, white = negative for negative grounded systems > >> white = positive, black = negative for pos grounded systems. > >> I take it a step further, and use white label tape with red lettering > >> that says "+ positive ground + ", > >> because I've seen so many problems with positive grounded systems, and > >> people not getting polarity correct. > >> All of this is NEC compliant, and follows standard conventions. > >> Make it easy on yourself and your journeymen on a hot roof, and have > >> your color coding match their multimeter. > >> You might save an inverter or even a life. > >> > >> R.Ray Walters > >> CTO, Solarray, Inc > >> Nabcep Certified PV Installer, > >> Licensed Master Electrician > >> Solar Design Engineer > >> 303 505-8760 > >> > >> On 6/28/2013 12:09 PM, Allan Sindelar wrote: > >>> On 6/28/2013 11:47 AM, a...@aramsolar.com wrote: > >>>> And of course Red for positive and black for negative. > >>>> Most building departments have not pick up on this yet. But they will. > >>>> Aram > >>> Where does "of course Red for positive and black for negative" come > >>> from, please? I only know it as an automotive standard that has often > >>> caused confusion when used by DIY offgridders in years past, as black > >>> thus could represent either positive or negative in a DC conductor > pair. > >>> Is there yet a convention for ungrounded arrays? While red and black > >>> are technically correct as ungrounded current-carrying conductors, use > >>> of this color convention could cause as much confusion as resolve it > >>> in the future. How about "black and black" or for that matter "yellow > >>> and orange" (if supplied by manufacturers) for ungrounded arrays? > >>> Thanks, Allan > >>> > >>> *Allan Sindelar* > >>> _Allan@positiveenergysolar.com_ <mailto:al...@positiveenergysolar.com> > >>> NABCEP Certified PV Installation Professional > >>> NABCEP Certified Technical Sales Professional > >>> New Mexico EE98J Journeyman Electrician > >>> Founder and Chief Technology Officer > >>> *Positive Energy, Inc.*, a Certified B Corporation^TM > >>> 3209 Richards Lane > >>> Santa Fe, New Mexico 87507 > >>> *505 424-1112 office 780-2738 cell* > >>> _www.positiveenergysolar.com_ <http://www.positiveenergysolar.com/> > >> --- end of quote --- > >> _______________________________________________ > >> List sponsored by Home Power magazine > >> > >> List Address: RE-wrenches@lists.re-wrenches.org > >> > >> Change email address & 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 > > > > Change email address & 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 > > Change email address & 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 > >
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