<p dir="ltr">We have standardized on DC markings White negative and Red positive.</p>
<p dir="ltr">Chris Mason<br>
Comet Systems<br>
Anguilla (264) 235-5670<br>
St. Kitts (869) 662-5670<br>
skype netconcepts</p>
<p dir="ltr">NABCEP Certified Solar PV Installer<br>
Renewable Energy Systems professional<br>
Generac Generators Factory technician</p>
<div class="gmail_quote">On Jun 29, 2013 8:30 PM, "David Katz" <<a href="mailto:dkatz@aeesolar.com">dkatz@aeesolar.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Watch out for accountants who become installers. They always thing red negative and black positive.<br>
David Katz<br>
<br>
Sent from my iPhone<br>
<br>
On Jun 28, 2013, at 5:40 PM, "Ray Walters" <<a href="mailto:ray@solarray.com">ray@solarray.com</a>> wrote:<br>
<br>
> Richard, when you use your Fluke 87 to measure Vdc, black is negative,<br>
> red is positive. The black is labeled common because the meter can also<br>
> be used for current measurements. (I have a Fluke 89)<br>
> When you start using black wire for positive, it may be allowed by code,<br>
> but there just isn't a good reason for it.<br>
> Its just too easy to make a mistake, and its just too easy to adhere to<br>
> the multimeter convention and keep it safer.<br>
><br>
> I have personally watched seasoned electricians argue color coding with<br>
> me, then minutes later get mixed up and wire two 10 module strings in<br>
> series, because they forgot for a moment that they were working on a<br>
> positive grounded system. The result was an almost 1000 v arc that<br>
> jumped an opened fuse holder (only rated to 600 vdc) and started a small<br>
> fire in the inverter, before I disconnected it at the array.<br>
><br>
> Please give one example where leaving positive unmarked with black wire<br>
> makes more sense than taping it. Colored electrical tape, and label<br>
> tape are much cheaper than inverters and people. THHN, USE, and PV wire<br>
> can all be purchased in red, white, and black. (which saves time with<br>
> multiple home runs)<br>
> Its not code yet, but it's good sense, all the way back to the color<br>
> coded jumper cables you might have in your trunk.<br>
> I have discussed this with many electricians over the years, but<br>
> eventually every single one sees that's its really easy, no cost, and<br>
> still code compliant to make things safer.<br>
><br>
> R.Ray Walters<br>
> CTO, Solarray, Inc<br>
> Nabcep Certified PV Installer,<br>
> Licensed Master Electrician<br>
> Solar Design Engineer<br>
> <a href="tel:303%20505-8760" value="+13035058760">303 505-8760</a><br>
><br>
> On 6/28/2013 2:49 PM, Richard L Ratico wrote:<br>
>> Respectfully:<br>
>> My Fluke 87 does not use this convention. Black is labeled the COMMON terminal,<br>
>> the red terminal is labeled according to function, not polarity. Battery based<br>
>> inverter manus. using this convention typically provide BOS enclosures with OCP<br>
>> for only one inverter conductor. This requires the other conductor to be<br>
>> grounded and colored white or gray. Therefore IMHO the manus. should use only +<br>
>> or - to identify inverter terminals. Many, if not most, battery companies do<br>
>> this already. Mr. Wiles is, of course, welcome to his opinion.<br>
>><br>
>> I would suggest we stay with the NEC required use of any color other than white,<br>
>> green or gray for ungrounded conductors. This gives installers some flexibility.<br>
>> It also encourages the guy on the hot roof or the gal in the stuffy mechanical<br>
>> room to check and double check, maybe triple check polarity, as they should be<br>
>> doing anyway. I do like the practice of enhanced identification of conductors in<br>
>> positive ground systems.<br>
>><br>
>> Dick Ratico<br>
>> Solarwind Electric<br>
>><br>
>><br>
>> --- You wrote:<br>
>> The convention of red for positive and black for negative is not just<br>
>> automotive. It is also used by all battery based inverter manus, all<br>
>> battery companies, and all multimeters.<br>
>> John Wiles also agrees;<br>
>> red = positive, black = negative for ungrounded systems<br>
>> red = positive, white = negative for negative grounded systems<br>
>> white = positive, black = negative for pos grounded systems.<br>
>> I take it a step further, and use white label tape with red lettering<br>
>> that says "+ positive ground + ",<br>
>> because I've seen so many problems with positive grounded systems, and<br>
>> people not getting polarity correct.<br>
>> All of this is NEC compliant, and follows standard conventions.<br>
>> Make it easy on yourself and your journeymen on a hot roof, and have<br>
>> your color coding match their multimeter.<br>
>> You might save an inverter or even a life.<br>
>><br>
>> R.Ray Walters<br>
>> CTO, Solarray, Inc<br>
>> Nabcep Certified PV Installer,<br>
>> Licensed Master Electrician<br>
>> Solar Design Engineer<br>
>> <a href="tel:303%20505-8760" value="+13035058760">303 505-8760</a><br>
>><br>
>> On 6/28/2013 12:09 PM, Allan Sindelar wrote:<br>
>>> On 6/28/2013 11:47 AM, <a href="mailto:aram@aramsolar.com">aram@aramsolar.com</a> wrote:<br>
>>>> And of course Red for positive and black for negative.<br>
>>>> Most building departments have not pick up on this yet. But they will.<br>
>>>> Aram<br>
>>> Where does "of course Red for positive and black for negative" come<br>
>>> from, please? I only know it as an automotive standard that has often<br>
>>> caused confusion when used by DIY offgridders in years past, as black<br>
>>> thus could represent either positive or negative in a DC conductor pair.<br>
>>> Is there yet a convention for ungrounded arrays? While red and black<br>
>>> are technically correct as ungrounded current-carrying conductors, use<br>
>>> of this color convention could cause as much confusion as resolve it<br>
>>> in the future. How about "black and black" or for that matter "yellow<br>
>>> and orange" (if supplied by manufacturers) for ungrounded arrays?<br>
>>> Thanks, Allan<br>
>>><br>
>>> *Allan Sindelar*<br>
>>> _Allan@positiveenergysolar.com_ <mailto:<a href="mailto:Allan@positiveenergysolar.com">Allan@positiveenergysolar.com</a>><br>
>>> NABCEP Certified PV Installation Professional<br>
>>> NABCEP Certified Technical Sales Professional<br>
>>> New Mexico EE98J Journeyman Electrician<br>
>>> Founder and Chief Technology Officer<br>
>>> *Positive Energy, Inc.*, a Certified B Corporation^TM<br>
>>> 3209 Richards Lane<br>
>>> Santa Fe, New Mexico 87507<br>
>>> *<a href="tel:505%20424-1112" value="+15054241112">505 424-1112</a> office 780-2738 cell*<br>
>>> _www.positiveenergysolar.com_ <<a href="http://www.positiveenergysolar.com/" target="_blank">http://www.positiveenergysolar.com/</a>><br>
>> --- end of quote ---<br>
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