Much of the confusion seems to be from the older versions of the
code. I actually find the 08 version to be less confusing overall (I
do have my issues though). It allows the WEEB system for instance,
which greatly speeds installations, and allows the array support
structure to be used as the grounding electrode (in some cases). It
seems to clarify some of the bonding issues as well. But with any
attempt to clarify comes more confusion. I personally don't see any
issue at all with the Enphase inverters. 690.47C (3) says "a single
conductor shall be permitted to be used to perform the multiple
functions of DC grounding, AC grounding, and bonding between AC & DC
systems."
Module is bonded to the array frame, frame is bonded to ground.
Enphase is bolted to the module frame (bonded) and bonded via its EGC
back with the AC conductors to the main ground buss.
Everyone is always trying to over complicate grounding issues
relative to PV systems. We just need to follow the same time tested
methods used on other wiring systems: Exposed metal is bonded to
ground in some reasonable manner, try to avoid ground loops, size the
EGC to table 250.122.....Now just to decide where it becomes a GEC.....
Ray Walters
Solarray.com
NABCEP # 04170442
On Jun 17, 2009, at 5:15 PM, Marv Dargatz wrote:
Keith,
The whole grounding issue has been very contentious, confounding,
and confusing. The introduction of the changes with the 2008 NEC
seems to have complicated things further.
Also, just a general comment; in general (there will be exceptions
for larger systems, depending on electrical configuration), this
code section applies equally to all PV inverters. There should be
no difference with an Enphase installation and a traditional string
installation.
What version of code are you referencing? 2005 and 2008 differ
slightly. I'd like to get a consensus on all of these grounding
issues. It's too late for the 2011 code, but maybe we can clear
this up with the 2014 code.
BTW, the explanatory note after paragraph 690.47(C)(8) in the 2008
handbook offers some clarification.
I'm anxious to get John W. and Bill B.'s opinion on this.
See Ya!
Marv
Enphase Energy
707 763-4784 x7016
Keith Cronin wrote:
Hello
A discussion came up today about 690.47(C)(1)+(2) in regards to
using the Enphase products and the applicability of needing a
separate ground rod for the DC?
Anyone get any feedback from their colleagues or inspectors
regarding this and how they approached this?
The discussion also swirled around them both being bonded
regardless, so the question of necessity was in question.
Thanks
Keith
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & 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
Options & 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
Options & 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
