[RE-wrenches] GEC for Micro-Inverters and ACPV Modules
Drake
drake.chamberlin at redwoodalliance.org
Wed Jan 16 11:30:49 PST 2013
There is one possible argument that might be
used. Sections of busbar are permitted to be
connected together 250-64 C 2. If the aluminum
frame and rail parts can be considered as
busbars, which they clearly are for grounding
purposes, this would apply. I don't know that too
many inspectors would buy this one, however.
At 01:17 PM 1/16/2013, you wrote:
>Content-Class: urn:content-classes:message
>Content-Language: en-US
>Content-Type: multipart/related;
> boundary="_004_B448FC9E37458B469E77EA0BB954AD4702B670A694mailbox01_";
> type="multipart/alternative"
>
>Mark:
>
>I agree that the Code requirement for GEC in grid tied PV makes no sense.
>I have been trying to get it changed since the 2005 Code cycle.
>Until it does change (not even likely in 2014)
>we are stuck with it
unless you float the array J
>
>Best Regards,
>
>John Berdner
>General Manager, North America
>
>SmallBannerPictEngnew
>
>
>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
>
>From: re-wrenches-bounces at lists.re-wrenches.org
>[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Mark Frye
>Sent: Wednesday, January 16, 2013 10:08 AM
>To: re-wrenches at lists.re-wrenches.org
>Subject: Re: [RE-wrenches] GEC for Micro-Inverters and ACPV Modules
>
>I believe the WEEB is a great product for
>producing equipment grounds. But for producing a
>GEC I don't see it. Even if I bond the inverter
>case to the rail with a WEEB what is the next
>step in the chain, a reversible WEEB lug to bond
>the rail to the wire. Still, I don't think the
>GEC for these microinverters is a rational
>requirement. It appears from the discussion that
>if I have a seperately installed microinverter
>that bonds it's DC side to ground, the Code
>requires a GEC but if I take that exact same
>inverter, assemble it to a module and test and
>list them as an AC module the requirement for
>GEC goes away. This is another indicator that
>the application of this requirement in the Code itself is specious.
>
>Mark Frye
>On 1/16/2013 9:53 AM, John Berdner wrote:
>Brain:
>
>Not trying to be argumentative here
>
>I understand that you feel that a WEEB is
>equivalent to an irreversibly spliced connection
>but, as most commonly used in the field, I disagree.
>The Code does not recognize bolted connections
>of any kind as equivalent to irreversible spliced or contiguous.
>It is an issue of the type of connection not the
>presence of the WEEB clip in that connection.
>For Example: If the WEEB connection was riveted
>in place then I believe it would be considered
>irreversibly spliced but as part of a bolted connection, no.
>
>With specific reference to GEC see 250.64C in
>the 2011 NEC or 2011 NEC Handbook.
>
>Lastly, the argument that it is a similar level
>of difficult to cutting the wire, while true, is
>not relevant to the Code requirement. Cutting a
>contiguous wire is also a similar level of
>difficulty to opening a bolted connection but
>obviously a bolted connection is not a contiguous wire.
>
>Best Regards,
>
>John Berdner
>General Manager, North America
>
>SmallBannerPictEngnew
>
>
>3347 Gateway Boulevard, Fremont CA 94538
>USA (*Please note of our new address.)
>T: 510.498.3201 ext 747
>M: 530.277.4894
>
>From:
><mailto:re-wrenches-bounces at lists.re-wrenches.org>re-wrenches-bounces at lists.re-wrenches.org
>[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of August Goers
>Sent: Wednesday, January 16, 2013 9:22 AM
>To: RE-wrenches
>Subject: Re: [RE-wrenches] GEC for Micro-Inverters and ACPV Modules
>
>Thanks Brian. This has been a helpful thread for
>me. Mark Frye, thanks for kicking it off.
>
>Best, August
>
>
>August Goers
>
>Luminalt Energy Corporation
>1320 Potrero Avenue
>San Francisco, CA 94110
>m: 415.559.1525
>o: 415.641.4000
><mailto:august at luminalt.com>august at luminalt.com
>
>From:
><mailto:re-wrenches-bounces at lists.re-wrenches.org>re-wrenches-bounces at lists.re-wrenches.org
>[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Brian Wiley
>Sent: Tuesday, January 15, 2013 1:02 PM
>To: RE-wrenches
>Subject: Re: [RE-wrenches] GEC for Micro-Inverters and ACPV Modules
>
>Hi August,
>
>I maintain that the WEEB is an irreversible splice.
>If you want to disconnect a WEEB from a
>structure, you must irreversibly damage the device. It cannot be reused.
>
>Admittedly the force required to remove a WEEB
>is less than that required for a thermal splice,
>but it doesn't take much force to just cut a wire either.
>
>I would argue that the intent of the code is to
>prevent inadvertent removal of the ground. You
>must knowingly remove a WEEB from the grounding
>path and if you do so in the maintenance of an
>array, good workmanship requires that you restore the connection.
>
>Best Regards,
>Brian Wiley
>
>
>On 1/15/2013 2:11 PM, August Goers wrote:
>
>Hi John,
>
>I definitely see your point and that is why I was somewhat questioning the
>use of WEEBs with Enphase below. Enphases's instructions (link posted in
>thread below) seem to indicate a support of running the continuous GEC on
>the rack and then bonding the microinverter to the rack with WEEBs. Maybe
>I am misinterpreting the document or perhaps Enphase has another take.
>There is no question that according to NEC 250.64(C) the GEC must be
>continuous. In the 2008 NEC handbook section 690.42 Point of System
>Grounding Connection has an application note "Connections are to be made
>in accordance with markings on the equipment or in the installation
>instructions."
>
>All that said, it seems like technology is leaning towards listed AC
>Modules or floating array inverters. It sounds like that removes the
>requirement for a GEC which is great to help reduce installation costs.
>The GEC has always been a pain in the neck.
>
>Best,
>
>August
>
>
>-----Original Message-----
>From:
><mailto:re-wrenches-bounces at lists.re-wrenches.org>re-wrenches-bounces at lists.re-wrenches.org
>[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of John
>Berdner
>Sent: Monday, January 14, 2013 7:07 PM
>To: RE-wrenches
>Subject: Re: [RE-wrenches] GEC for Micro-Inverters and ACPV Modules
>
>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:
><mailto:re-wrenches-bounces at lists.re-wrenches.org>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>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/>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:
><mailto:re-wrenches-bounces at lists.re-wrenches.org>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:
><mailto:RE-wrenches at lists.re-wrenches.org>RE-wrenches at lists.re-wrenches.org
>
>Options & settings:
><http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>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>http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
>List rules & etiquette:
><http://www.re-wrenches.org/etiquette.htm>www.re-wrenches.org/etiquette.htm
>
>Check out participant bios:
><http://www.members.re-wrenches.org>www.members.re-wrenches.org
>_______________________________________________
>List sponsored by Home Power magazine
>
>List Address:
><mailto:RE-wrenches at lists.re-wrenches.org>RE-wrenches at lists.re-wrenches.org
>
>Options & settings:
><http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>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>http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
>List rules & etiquette:
><http://www.re-wrenches.org/etiquette.htm>www.re-wrenches.org/etiquette.htm
>
>Check out participant bios:
><http://www.members.re-wrenches.org>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
>_______________________________________________
>List sponsored by Home Power magazine
>
>List Address:
><mailto:RE-wrenches at lists.re-wrenches.org>RE-wrenches at lists.re-wrenches.org
>
>Options & settings:
><http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>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>http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
>List rules & etiquette:
><http://www.re-wrenches.org/etiquette.htm>www.re-wrenches.org/etiquette.htm
>
>Check out participant bios:
><http://www.members.re-wrenches.org>www.members.re-wrenches.org
>_______________________________________________
>List sponsored by Home Power magazine
>
>List Address:
><mailto:RE-wrenches at lists.re-wrenches.org>RE-wrenches at lists.re-wrenches.org
>
>Options & settings:
><http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>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>http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
>List rules & etiquette:
>
><http://www.re-wrenches.org/etiquette.htm>www.re-wrenches.org/etiquette.htm
>
>Check out participant bios:
><http://www.members.re-wrenches.org>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
>
>
>
>
>_______________________________________________
>List sponsored by Home Power magazine
>
>List Address:
><mailto:RE-wrenches at lists.re-wrenches.org>RE-wrenches at lists.re-wrenches.org
>
>Options & settings:
><http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>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>http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
>List rules & etiquette:
><http://www.re-wrenches.org/etiquette.htm>www.re-wrenches.org/etiquette.htm
>
>Check out participant bios:
><http://www.members.re-wrenches.org>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
>
>
>_______________________________________________
>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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130116/2af8af50/attachment-0004.html>
More information about the RE-wrenches
mailing list