[RE-wrenches] GEC for Micro-Inverters and ACPV Modules

John Berdner John.Berdner at solaredge.com
Mon Jan 14 19:06:58 PST 2013


August:

The WEEB or other Listed grounding means between the inverter case and the structure are not "contiguous or irreversible spliced" and therefore do not meet the requirements for a GEC.
If the structure is then grounded via a bolt on lug it also is not irreversible or contiguous.
If you can unbolt something and disconnect the ground then it is not contiguous or irreversibly spliced.
Both of the above are ok for EGC but not for GEC.

GEC is a pain in the neck but the Code requirements are clear.
If the PV array conductor (pos or neg) is bonded to ground by the inverter then the inverter requires a GEC with all the related requirements - no if and's or but's.

Best Regards,

John Berdner
General Manager, North America

SolarEdge Technologies, Inc.
3347 Gateway Boulevard, Fremont CA 94538 USA  (*Please note of our new address.)
T: 510.498.3201 ext 747
M: 530.277.4894


-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of August Goers
Sent: Monday, January 14, 2013 4:32 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] GEC for Micro-Inverters and ACPV Modules

Hi Mark,

There have been some recent threads on this list touching on this topic.

As far as I understand, Enphase microinvertes still require a GEC up to and including the 2011 NEC. I don't know about the 2014 NEC. Enphase bonds the positive DC module conductor to ground. Pages 16 and 17 of their M215 installation manual address grounding:

http://enphase.com/wp-uploads/enphase.com/2011/06/Enphase_M215_Installatio
nOperation_Manual.pdf

Products such as Solar Bridge that are listed as Alternating Current (AC) Modules (per NEC 690.2) don't need a Grounding Electrode Conductor (GEC) as long as there are no conductors connected to ground within the product.
Solar Bridge has a good article on this:

http://solarbridgetech.com/microinverters-and-ac-pv-modules-are-different/

This all takes us back to using Enphase with grounding washers like WEEBs for the GEC. According to what I read in their instructions (and after many phone calls), it sounds like they are okay with us running the GEC on the racking in #6 and then bonding the microinverters to the rack with WEEBs. Seems a little strange but it's been working for us.

Good topic!

Best,

August
415.559.1525


-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Mark Frye
Sent: Monday, January 14, 2013 3:31 PM
To: RE-wrenches
Subject: [RE-wrenches] GEC for Micro-Inverters and ACPV Modules

Does anyone have the latest on the GEC for micro-inverters/ACPV issue?

I know it is still in NEC 2008 and I believe 2011 with plans to address it in 2014.

I am specifically interested in the issue of GEC means continues (irreversible splices) and the whole business of the DC side of these devices constituting a separately derived system.

Enphase technical support is fine if the micro inverter chasis is bonded to a EGC only, but they leave the lug on the chasis if you want/need to build a GEC.

SolarBridge (pre-assembled micro-inverter) seems to be devoid of a chasis lug and therefore by extension does not/can not had a GEC in the system.

Exeltech (integrated micro-inverter aka. ACPV) does not seem to have a lug on its chasis.

Has the industry pretty much moved to not requiring a GEC for these devices and if so, how are the AHJ taking it?

Thanks,
Mark Frye
Berkeley Solar Electric Systems
_______________________________________________
List sponsored by Home Power magazine

List Address: RE-wrenches at 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 at 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


CONFIDENTIALITY NOTICE: This e-mail and its attachments are intended only for the use of the individual or entity who is the intended recipient and may contain information that is privileged, confidential and exempt from disclosure or any type of use under applicable law. If the reader of this e-mail is not the intended recipient, or the employee, agent, or representative responsible for delivering the e-mail to the intended recipient, you are hereby notified that any dissemination, distribution, copying, or other use of this e-mail is strictly prohibited. If you have received this e-mail in error, please reply immediately to the sender.
P Please think of the environment before printing this email



More information about the RE-wrenches mailing list