<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
However, in this case, Peter's installing lots of 120 vac branch
circuits, so all of those neutrals will be carrying full current
(unless they are shared neutral circuits). Mike Holt's exception
would apply to 240vac circuits if they had a neutral. Further,
Holt's exception would not be applicable on any off grid system that
was 120 vac only.<br>
<pre class="moz-signature" cols="72">R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760</pre>
<div class="moz-cite-prefix">On 4/24/2016 12:58 AM, James Rudolph
wrote:<br>
</div>
<blockquote
cite="mid:CAA4FQ5qwco3S8H47tEQ-Eue=qBE=tO3hTKphxL2QSxHLQ20N4w@mail.gmail.com"
type="cite">
<div dir="ltr">Straight from Mike Holt:
<div><br>
</div>
<div>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif"><b>Neutral Conductor</b></p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">The neutral conductor of a 3-wire
single-phase 120/240V system, or 4-wire 3-phase 120/208V or
277/408V wye-connected system isn’t considered a
current-carrying conductor.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">The neutral conductor of a 3-wire circuit
from a 4-wire 3-phase 120/208V or 277V/480V wye-connected
system is considered a current-carrying conductor.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">When a 3-wire circuit is supplied from a
4-wire 3-[phase wye-connected system, the neutral conductor
carries approximately the same current as the ungrounded
conductors.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">The neutral conductor of a 4-wire 3-phase
circuit is considered a current-carrying conductor where the
major portion of the neutral load consists of nonlinear
loads. This is because harmonic currents will be present in
the neutral conductor, even if the loads on each of the 3
phases are balanced.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">Nonlinear loads supplied by 4-wire 3-phase
120/208V or 277/480V wye-connected systems can produce
unwanted and potentially hazardous triplen harmonic currents
(3rd, 9th, 15th, etc.) that can add on the neutral
conductor. To prevent fire or equipment damage from
excessive harmonic neutral current, the designer should
consider increasing the size of the neutral conductor or
installing a separate neutral for each phase. see 210.4(A)
FPN, 220.61 FPN 2, and 450.3 FPN 2.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">Grounding (earthing) and bonding
conductors aren’t considered current carrying.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">For individual dwelling units or
one-family, two-family, and multifamily dwellings, Table
310.15(B)(6) can be used to size 3-wire single-phase
120/240V service or feeder conductors (including neutral
conductors) that serve as the main power feeder. Feeder
conductors are not required to have an ampacity rating
greater than the service conductors [215.2(A)(3)].</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">Warning: Table 310.15(B)(6) doesn’t apply
to 3-wire single-phase 120/208V systems, because the
grounded neutral conductor in these systems carries neutral
current even when the load on the phases is balanced
[310.15(B)(4)(6)]. For more information on this topic, see
220.61(C)(1).</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif"><i>Grounded Neutral Conductor Sizing.</i> Table
310.15(B)(6) can be used to size the grounded neutral
conductor of a 3-wire single-phase 120/240V service or
feeder that serves as the main power feeder, based on the
feeder calculated load in accordance with 220.61.</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">Because the grounded neutral service
conductor is required to serve as the effective ground-fault
current path, it must be sized so that it can safely carry
the maximum fault current likely to be imposed on it [110.10
and 250.4(A)(5)]. This is accomplished by sizing the
grounded neutral conductor in accordance with Table 250.66,
based on the total area of the largest ungrounded conductor
[250.24(C)(1)].</p>
<p style="margin:1em
0px;font-size:15px;line-height:1.48em;color:rgb(51,51,51);font-family:Georgia,Times,'Times
New Roman',serif">aloha and happy trails...</p>
</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Thu, Apr 21, 2016 at 10:28 AM, Peter
Parrish <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:peter.parrish@calsolareng.com"
target="_blank">peter.parrish@calsolareng.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="white" link="blue" vlink="purple" lang="EN-US">
<div>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">William,</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I
agree about the subpanel in the house situation. The
customer is a bit eccentric, and I have tried to
bring him around. And I have explained to him that
his approach will be more expensive. He doesn’t
care. In the end, there is no safety risk. So I’ll
plan for 4 branch circuits per conduit and take the
0.70 derating.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">-
Peter </span></p>
<span class="">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<div>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Peter
T. Parrish, Ph.D.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">President,
SolarGnosis</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">1107
Fair Oaks Ave.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Suite
351</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">South
Pasadena, CA 91030</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a
moz-do-not-send="true"
href="tel:%28323%29%20839-6108"
value="+13238396108" target="_blank">(323)
839-6108</a></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a
moz-do-not-send="true"
href="mailto:petertor@pobox.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:petertor@pobox.com">petertor@pobox.com</a></a></span><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"></span></p>
</div>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
</span>
<div>
<div style="border:none;border-top:solid #b5c4df
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
RE-wrenches [mailto:<a moz-do-not-send="true"
href="mailto:re-wrenches-bounces@lists.re-wrenches.org"
target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>]
<b>On Behalf Of </b>William Miller<br>
<b>Sent:</b> Thursday, April 21, 2016 10:25 AM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] Does a Neutral
Count as a CCC</span></p>
</div>
</div>
<div>
<div class="h5">
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">Peter:</span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">I
think it is a mistake to not locate a sub-panel
in the house. Running branch circuits 45 feet
to a separate building is not efficient or
practical.</span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">Voltage
drop: 1% VD is a choice, not a requirement.
Code requires 3% on feeders and 5% cumulative on
AC branch circuits. I like to use 1% for
average voltage drop for PV because of the cost
of wasted PV energy. I am more lax on AC
circuits. If I calculate a PV feeder for 1%,
that drop will occur only occasionally, when
peak solar is achieved. Analyze your load or
charging profiles and look for a calc that
provides the chosen VD for average use.
Analyzing PV energy curves over a given day,
approximately 50% of the energy is under the
bell curve.</span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">Neutrals
are current carrying. Try powering a 120VAC
load without one and you will see what I mean.</span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">William
Miller</span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<div>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><img
src="cid:part5.09070705.06090706@solarray.com" alt="Gradient Cap_mini"
height="28" width="64"><br>
Lic 773985<br>
<a moz-do-not-send="true"
href="http://www.millersolar.com/"
target="_blank">millersolar.com</a><br>
<a moz-do-not-send="true"
href="tel:805-438-5600" value="+18054385600"
target="_blank">805-438-5600</a></span></p>
</div>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""> </span></p>
<div>
<div style="border:none;border-top:solid #b5c4df
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
RE-wrenches [mailto:<a
moz-do-not-send="true"
href="mailto:re-wrenches-bounces@lists.re-wrenches.org"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a></a>]
<b>On Behalf Of </b>Peter Parrish<br>
<b>Sent:</b> Thursday, April 21, 2016 8:57
AM<br>
<b>To:</b> 'RE-wrenches'<br>
<b>Subject:</b> [RE-wrenches] Does a Netral
COunt as a CCC</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I
am working with a customer who is doing a
complete remodel and addition to his house:
stripped to the open studs and floor joists, and
rafters. Not a wire in the house. We have
designed a 14.4 kWp PV system with 16 kW of
storage for backup and load shifting. The main
panel, inverters, critical load subpanel and
batteries are all going to be in the garage
which is about 45 feet from the house. The
customer and I have identified the critical
loads.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">The
GC is running conduit from the main house to the
garage. I have been given seven (7) 1-1/2” PVC
conduits, and I am currently doing conduit fill,
ampacity and voltage drop calculations for the
branch circuits that represent the critical
loads.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">So
I have two questions:</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p><span>(1)<span style="font:7.0pt "Times New
Roman""> </span></span><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Should
I stick to a <1% voltage drop on all
circuits?</span></p>
<p><span>(2)<span style="font:7.0pt "Times New
Roman""> </span></span><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Do
120 V neutrals count as current carrying
conductors? I think they do, but the electrician
stated quite emphatically that they didn’t. I
thought that the derating calcs for CCCs were
based solely on ohmic losses and phasing was not
taken into account.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Does
the NEC provide guidance on this latter
situation?</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p><span
style="font-family:"Calibri","sans-serif""><span>-<span
style="font:7.0pt "Times New
Roman""> </span></span></span><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Peter
Parrish</span></p>
<div>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Peter
T. Parrish, Ph.D.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">President,
SolarGnosis</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">1107
Fair Oaks Ave.</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Suite
351</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">South
Pasadena, CA 91030</span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a
moz-do-not-send="true"
href="tel:%28323%29%20839-6108"
value="+13238396108" target="_blank">(323)
839-6108</a></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a
moz-do-not-send="true"
href="mailto:petertor@pobox.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:petertor@pobox.com">petertor@pobox.com</a></a></span></p>
</div>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
</div>
</div>
</div>
</div>
<br>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
List Address: <a moz-do-not-send="true"
href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a moz-do-not-send="true"
href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org"
rel="noreferrer" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
List-Archive: <a moz-do-not-send="true"
href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html"
rel="noreferrer" target="_blank">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a><br>
<br>
List rules & etiquette:<br>
<a moz-do-not-send="true"
href="http://www.re-wrenches.org/etiquette.htm"
rel="noreferrer" target="_blank">www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a moz-do-not-send="true"
href="http://www.members.re-wrenches.org" rel="noreferrer"
target="_blank">www.members.re-wrenches.org</a><br>
<br>
<br>
</blockquote>
</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature">
<div dir="ltr"><b><br>
James B. Rudolph</b>
<div><b>Haleakala Solar</b> <b><br>
</b>
<div><b>Director of Construction</b></div>
<div><b>NABCEP Certified PV Installer # 091209-155<br>
</b></div>
<div><b><br>
</b></div>
<div><b><br>
</b></div>
<div><br>
<b><img moz-do-not-send="true" alt=""><br>
</b><br>
</div>
</div>
</div>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
List sponsored by Redwood Alliance
List Address: <a class="moz-txt-link-abbreviated" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>
Change listserver email address & settings:
<a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a>
List-Archive: <a class="moz-txt-link-freetext" href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a>
List rules & etiquette:
<a class="moz-txt-link-abbreviated" href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a>
Check out or update participant bios:
<a class="moz-txt-link-abbreviated" href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a>
</pre>
</blockquote>
<br>
</body>
</html>