That only works for a negative grounded system.
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 6/30/2013 7:48 AM, Chris Mason wrote:
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 Installer^(TM)
Renewable Energy Systems professional
Generac Generators Factory technician
On Jun 29, 2013 8:30 PM, "David Katz" <dk...@aeesolar.com
<mailto: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
<mailto: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 <tel:303%20505-8760>
>
> 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 <tel:303%20505-8760>
>>
>> On 6/28/2013 12:09 PM, Allan Sindelar wrote:
>>> On 6/28/2013 11:47 AM, a...@aramsolar.com
<mailto: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
<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 <tel:505%20424-1112> office 780-2738 cell*
>>> _www.positiveenergysolar.com_
<http://www.positiveenergysolar.com/>
>> --- end of quote ---
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