[RE-wrenches] Cable sizing for high current modules? NEC interpretation/guidance?

Fri Nov 10 08:24:24 PST 2023

Wrenches
For many years we used Sharp modules, yes they had issues but l dont recall
many if at all MC failurs but with SolarWorld a very high number of
failures. With some overseas manufacturers I have also seen this level of
failure so it does start to look like the sub that made the cables is the
issue. Now years ago some MC Knock offs hit the market, say10 to 15 years
ago. Issues like this may also be a factor.
Fun times

On Fri, Nov 10, 2023, 7:41 AM Jay via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> I’ve wondered what other variables are at work given that mostly these
> connectors work as they should.
>
> I’d like to see them come with plugs covering the openings. This would
> keep dirt, salt air, moisture, etc  out until they are connected.
>
> As to if there were lots of failures with SW modules then I wonder if
> whoever built the whips had poor quality control. Might be they were not
> seated properly or dirty or the crimp they used wasn’t calibrated correctly
> or they were stored in a salt environment creating corrosion or something
> like that.
>
> I looked up the specs last night on the mc4 and it’s like 30+ amps
> depending on the wire, pretty impressive
>
> Jay
>
>
>
>
>
>
>
> On Nov 10, 2023, at 5:53 AM, Dave Tedeyan via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> 
> Mine was a roof mount. We had very few SolarWorld projects. In fact, this
> might be our only one.
>
> On Fri, Nov 10, 2023, 8:10 AM Chris Schaefer via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
>> I'd be curious to know of the connector failures y'all have experienced,
>> were the majority of these roof mounts?
>> Just wondering if with better air flow like that of a pole/ground mount,
>> if that helped to minimize connector failure.
>>
>> Christopher
>>
>> On Fri, Nov 10, 2023 at 1:21 AM Bill Battagin via RE-wrenches <
>> re-wrenches at lists.re-wrenches.org> wrote:
>>
>>> Ray,
>>>
>>>             Exactly the same thing happened for me on a ground mount
>>> system, 3500 feet elevation the the Sierras so open cooler air, fully
>>> engaged MC4 factory connectors PV to PV connectors with SW285's, not
>>> passing current, melted.  No attempt to contact SW just made up new
>>> connectors.
>>>
>>>             My calculation is with anything that is no doubt made up by
>>> the bazillion with a machine (connectors, light bulbs, pencils, chicken
>>> nuggets, etc) you're going to get some duds.  In 20+ years of installing
>>> PVs with factory made-up connectors, I've only seen this happen 2-3 times.
>>> Installing in the mountains we no doubt use ground mount much more often
>>> than most installs in urban areas which would make a hot, melted connector
>>> possibly more of an issue a couple inches above a comp or wood roof.  We've
>>> never seen any connectors fail beyond the melted/deformed but still
>>> "contained" stage .
>>>
>>>             Back when SW was first transitioning from one connector to
>>> another, I remember them saying they (I think it was UTX and MC or was it
>>> UTX and Amphenol?) were compatible.  We NEVER mixed connectors despite
>>> their claim.
>>>
>>> Bill
>>>
>>> Feather River Solar Electric
>>> 4291 Nelson St. (Shipping)
>>> 5575 Genesee Rd. (USPS, UPS)
>>> Taylorsville, CA  95983
>>> 530-284-7849, 258-1641(cell)
>>> CA. C10 Lic # 874049
>>> Solar Powered since 1982
>>> Home of the Sunny Side Up
>>>
>>> On 11/9/2023 4:31 PM, Ray Walters via RE-wrenches wrote:
>>>
>>> I'm trying to find a pic to post, but they were MC4 connectors, not the
>>> UTX.
>>>
>>> Ray
>>> On 11/9/2023 4:57 PM, Brian Mehalic wrote:
>>>
>>> Are they the Amohenol UTX connectors? SW had a recall on them, sounds
>>> like about the right timeframe.
>>>
>>> BREAKING: SolarWorld recalls PV modules with Amphenol connectors
>>> <https://pv-magazine-usa.com/2017/03/29/solarworld-recalls-amphenol-connectors-sold-with-pv-modules/>
>>> pv-magazine-usa.com
>>> <https://pv-magazine-usa.com/2017/03/29/solarworld-recalls-amphenol-connectors-sold-with-pv-modules/>
>>>
>>> <https://pv-magazine-usa.com/2017/03/29/solarworld-recalls-amphenol-connectors-sold-with-pv-modules/>
>>>
>>>
>>> Brian
>>>
>>> On Nov 9, 2023, at 4:47 PM, Ray Walters via RE-wrenches
>>> <re-wrenches at lists.re-wrenches.org> <re-wrenches at lists.re-wrenches.org>
>>> wrote:
>>>
>>> 
>>>
>>> 12 Ga wire is not going to catch on fire, but the MC connectors might.
>>> I just went back on a 7 yr old Solarworld install, and had a bad series MC
>>> connector (module to module).  It got quite crispy, deforming and bubbling
>>> the plastic on both sides of the connection.  It was still passing current;
>>> I didn't get a chance to measure the volt drop.  It was completely plugged
>>> in, so not an installation issue.
>>>
>>> This was not one of our connectors made up in the field, these were
>>> Solarworld factory connectors on both sides, same model modules.  That also
>>> means no mismatch of "MC4" connector type.
>>>
>>> 10+ amps continuous, moist environment, 30F+  hotter than ambient temp,
>>> all are tough on connectors.  I predict more connector failures as module
>>> current ratings increase.
>>>
>>> Ray Walters
>>> Remote Solar
>>> On 11/9/2023 3:02 PM, Glenn Burt via RE-wrenches wrote:
>>>
>>> Good luck trying to convince your customer that their house caught on
>>> fire because of a manufacturers flaw, and you have no responsibility for it…
>>>
>>> It may be an out to shift the blame, but it only makes everybody get
>>> some on them…
>>>
>>>
>>>
>>> *From:* RE-wrenches <re-wrenches-bounces at lists.re-wrenches.org>
>>> <re-wrenches-bounces at lists.re-wrenches.org> *On Behalf Of *William
>>> Miller via RE-wrenches
>>> *Sent:* Wednesday, November 08, 2023 12:14 PM
>>> *To:* RE-wrenches <re-wrenches at lists.re-wrenches.org>
>>> <re-wrenches at lists.re-wrenches.org>
>>> *Cc:* William Miller <william at millersolar.com> <william at millersolar.com>
>>> *Subject:* Re: [RE-wrenches] Cable sizing for high current modules? NEC
>>> interpretation/guidance?
>>>
>>>
>>>
>>> George:
>>>
>>>
>>>
>>> Appliance manufacturers have their own requirements that are not the
>>> same as the NEC requirements.  As long as you are not modifying the
>>> manufactured assembly you are not responsible for compliance of that
>>> appliance.  By appliance, I mean the solar module, microinverter, etc.
>>>
>>>
>>>
>>> William Miller
>>>
>>>
>>>
>>> Miller Solar
>>>
>>> 17395 Oak Road, Atascadero, CA 93422
>>>
>>> 805-438-5600
>>>
>>> www.millersolar.com
>>>
>>> CA Lic. 773985
>>>
>>>
>>>
>>>
>>>
>>> *From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
>>> Behalf Of *George McClellan via RE-wrenches
>>> *Sent:* Wednesday, November 8, 2023 9:06 AM
>>> *To:* RE-wrenches
>>> *Cc:* George McClellan
>>> *Subject:* [RE-wrenches] Cable sizing for high current modules? NEC
>>> interpretation/guidance?
>>>
>>>
>>>
>>> Team;
>>>
>>>
>>>
>>> With the move to larger cells, some modules have an Isc that is pushing
>>> the limits of 12 AWG wire.  If I apply the rule of 156% (or 125% solar
>>> derate*125% continuous load derate) to an 18 Amp Isc module this will
>>> exceed the 25A that a 12 AWG wire can carry.  I understand that the
>>> homeruns will need to be a larger AWG (10 ga), but do the solar module
>>> cables (from junction box to MC4) also need to be larger?  Any guidance or
>>> reference material would be greatly appreciated.
>>>
>>>
>>>
>>> Thx,
>>>
>>>
>>>
>>> George McClellan | Senior Technical Sales Manager | REC Americas LLC
>>>
>>> 330 James Way Ste 150 | Pismo Beach, CA 93449 | USA
>>>
>>> Cell phone +1 805 704 3226 | Fax +1 805 357 6104
>>>
>>> www.recgroup.com | george.mcclellan at recgroup.com
>>> <shannon.kent at recgroup.com>
>>>
>>>
>>>
>>>
>>> ------------------------------
>>>
>>>
>>> This message is private and confidential and may be privileged. Any
>>> unauthorized use, dissemination of the information or copying of this
>>> message is prohibited. If you have received this message in error, please
>>> notify us immediately and remove it from your system. Thank you.
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> Pay optional member dues here: http://re-wrenches.org
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>>
>>> Change listserver email address & settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> There are two list archives for searching. When one doesn't work, try the other:https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>>
>>> List rules & etiquette:http://www.re-wrenches.org/etiquette.htm
>>>
>>> Check out or update participant bios:http://www.members.re-wrenches.org
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> Pay optional member dues here: http://re-wrenches.org
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> There are two list archives for searching. When one doesn't work, try
>>> the other:
>>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>>
>>> List rules & etiquette:
>>> http://www.re-wrenches.org/etiquette.htm
>>>
>>> Check out or update participant bios:
>>> http://www.members.re-wrenches.org
>>>
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> Pay optional member dues here: http://re-wrenches.org
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>>
>>> Change listserver email address & settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> There are two list archives for searching. When one doesn't work, try the other:https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>>
>>> List rules & etiquette:http://www.re-wrenches.org/etiquette.htm
>>>
>>> Check out or update participant bios:http://www.members.re-wrenches.org
>>>
>>>
>>>
>>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
>>> Virus-free.www.avast.com
>>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
>>> <#m_-6374991197620274521_m_8749843072533026636_m_-436569653518949353_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> Pay optional member dues here: http://re-wrenches.org
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> There are two list archives for searching. When one doesn't work, try
>>> the other:
>>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>>
>>> List rules & etiquette:
>>> http://www.re-wrenches.org/etiquette.htm
>>>
>>> Check out or update participant bios:
>>> http://www.members.re-wrenches.org
>>>
>>>
>>
>> --
>>
>> Chris Schaefer’s
>>
>>
>> *Tel 585-229-2083 or Cell 585-748-1870 *
>> *5115 S Hill Road ~ Canandaigua New York 14424**www.solarandwindfx.com
>> <http://www.solarandwindfx.com> ~ E-mail: chris at solarandwindfx.com
>> <chris at solarandwindfx.com>*
>>
>>
>> Thomas Jefferson, the author of our great Constitution, once said,
>> "democracy" will cease to exist when you take away from those who are
>> willing to work and give to those who would not."
>> _______________________________________________
>> List sponsored by Redwood Alliance
>>
>> Pay optional member dues here: http://re-wrenches.org
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>>
>> Change listserver email address & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> There are two list archives for searching. When one doesn't work, try the
>> other:
>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>
>> List rules & etiquette:
>> http://www.re-wrenches.org/etiquette.htm
>>
>> Check out or update participant bios:
>> http://www.members.re-wrenches.org
>>
>> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> There are two list archives for searching. When one doesn't work, try the
> other:
> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> http://www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> http://www.members.re-wrenches.org
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> There are two list archives for searching. When one doesn't work, try the
> other:
> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> http://www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> http://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/20231110/b1230ad6/attachment.htm>