[RE-wrenches] GEC for Enphase inverters

Mark Frye markf at berkeleysolar.com
Tue Sep 14 11:01:32 PDT 2010


"Since the GEC for Enphase starts at the inverter on the roof, you must have
a minimum of 8AWG running among the microinverters and down to the grounding
electrode system. In the 2008 NEC and 2011 NEC, this conductor can serve the
purpose of the ac EGC as well and can be terminated on the service panel
grounding bus."
 
Yes, but this conductor does not need to be "unboken", correct?
 
This conductor, running among the microinverters can be terminated onto a
mechanical pressure terminal which serves as the equipment ground buss in a
load center which is not part of service enterance equipment and may be
located anywhere on the premise. The remainder of the circuit is then
provided by the EGC as it runs back to the service enterance and then the
GEC to the GES. Correct?


Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  

 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Bill Brooks
Sent: Tuesday, September 14, 2010 8:41 AM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] GEC for Enphase inverters



Mark and Rebekah,

 

The term "continuous" is a requirement for any circuit and implies
electrical continuity and current-carrying capability. Both the GEC and EGC
must be continuous or you don't got one. It is not defined in NEC Article
100.

 

What most people are referring to when they say that a GEC must be
continuous is "unbroken" or the NEC talks about "irreversibly spliced."
Splicing of a GEC is usually a last resort because there is no other option.
For instance, multiple bonding jumpers coming off of multiple inverters
would need to be irreversibly spliced to the main GEC that should proceed
unbroken from the farthest inverter from the grounding electrode. 250.66 for
ac and 250.166 for dc are consistent in requiring the minimum GEC to be 8AWG
copper. Since the GEC for Enphase starts at the inverter on the roof, you
must have a minimum of 8AWG running among the microinverters and down to the
grounding electrode system. In the 2008 NEC and 2011 NEC, this conductor can
serve the purpose of the ac EGC as well and can be terminated on the service
panel grounding bus.

 

Bill.

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Rebekah Hren
Sent: Tuesday, September 14, 2010 7:25 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] GEC for Enphase inverters

 


The code does require the GEC to be continuous (250.64C), and I believe that
the AC EGC for the Enphase metal inverter cases is in fact the same as the
DC GEC since the point of system bonding on the DC side is inside the
inverter. 

See art. 100 definitions:Grounding Electrode Conductor. A conductor used to

connect the system grounded conductor...to a point on the grounding
electrode

system.


So this means that for Enphase systems the AC EGC (which is also the DC GEC)
should be at minimum 8 awg (250.66) and continuous? Seems like it to me. 

 

Rebekah Hren

 



--- On Tue, 9/14/10, Mark Frye <markf at berkeleysolar.com> wrote:


From: Mark Frye <markf at berkeleysolar.com>
Subject: Re: [RE-wrenches] GEC for Enphase inverters
To: "'RE-wrenches'" <re-wrenches at lists.re-wrenches.org>
Date: Tuesday, September 14, 2010, 10:05 AM

I believe the AC GEC runs from; the point where the ungrounded current
carrying conductor is bonded to the enclosure of the service enterance
equipment; to the connection to the ground electrode system. Conductors that
run from the service enterance equipment, thru the premis to the Enphase are
bonding jumpers that are not required to be continuous.

 

Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  

 

 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of William
Miller
Sent: Monday, September 13, 2010 9:46 PM
To: RE-wrenches
Subject: [RE-wrenches] GEC for Enphase inverters

Friends:

According to the 2005 NEC 250.64(C), the GEC for an AC system needs to be
continuous without splices unless they are irreversible.  I am not clear
where this conductor starts and ends.  Is it from the ground buss in a
sub-panel to the disconnect switch on the roof, or to each inverter?

Also, non-reversible splices need to be listed for use in grounding systems.
Any suggestions on make and model of splices so listed?

Any advise from those more experienced is much appreciated.

William Miller

Please note new e-mail address and domain:

William Miller 
Miller Solar
Voice :805-438-5600
email: william at millersolar.com
http://millersolar.com <http://millersolar.com/> 
License No. C-10-773985


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