[RE-wrenches] double insulated wire
Ray Walters
ray at solarray.com
Mon Jul 1 07:48:59 PDT 2013
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" <dkatz at aeesolar.com
> <mailto:dkatz at 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" <ray at solarray.com
> <mailto:ray at 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, aram at aramsolar.com
> <mailto:aram at 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 at positiveenergysolar.com_
> <mailto:Allan at positiveenergysolar.com
> <mailto:Allan at 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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