[RE-wrenches] TL inverter with long DC Feeder

Chris Mason cometenergysystems at gmail.com
Mon Oct 6 16:49:30 PDT 2014


If it is a TL, there is a combiner input, and yes, you can use no fuses for
two strings.

On Mon, Oct 6, 2014 at 6:27 PM, William Miller <william at millersolar.com>
wrote:

> Mike:
>
>
>
> If I have just two strings of Solarworld SW275 modules per inverter, can I
> use one input to the built-in combiner to feed in a combined string?  My
> calculations indicate that I might be able to feed the two strings into one
> 25 amp KLKD fuse.  The Isc is 8.94.  times 1.25 = 11.715.  Times 2 = 22.35.
>
>
>
> The manual says use of any fuse higher than 20 amps voids the warranty.
> Could an exception be made if only one set of 25 amp fuses were installed?
>
>
>
> William
>
>
>
>
>
> PS:  I am not sure fuses are required in a combiner with just two
> strings.  The SW275 module can withstand 16 amp external feed (from the max
> fuse rating).  A parallel module will output 8.94 times 1.56 or 13.95. This
> is less than the 16 amps.  This used to be allowed in earlier versions of
> the code,  I will have to look and see if it still is.
>
>
>
> Wm
>
>
>
>
>
> [image: Gradient Cap_mini]
> Lic 773985
> millersolar.com <http://www.millersolar.com/>
> 805-438-5600
>
>
>
> *From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
> Behalf Of *Michael Kelly
> *Sent:* Monday, October 06, 2014 3:10 PM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] TL inverter with long DC Feeder
>
>
>
> Hi William,
>
>
>
> I wanted to let you know that currently, there is no bypass terminal to
> allow for combining at the array in this series of inverters. We have
> gotten a lot of feedback from customers that this is a required feature.
> Working toward that, in the next few months, we will phase into production
> an update that will include a bypass, but the existing stock does not have
> the feature.
>
>
>
> I wanted to let you know so you could plan appropriately.
>
>
>
> Best,
>
> Mike
>
>
>
> *Michael Kelly*
>
> [image: Solectria_Yaskawa_signature_logo] <http://www.solectria.com/>
>
> HQ: 360 Merrimack Street, Bldg 9, Fl 2, Entrance I, Lawrence, MA 01843 USA
>
> O: +1 978-683-9700 x167 | F: +1 978-683-9702
>
> *mike.kelly at solectria.com <mike.kelly at solectria.com>* | www.solectria.com
>
>
>
> *NOTICE:* This e-mail may contain confidential and/or privileged
> information. If you are not the intended recipient, or an authorized
> representative of the recipient, please be advised that you may not use,
> copy or disclose its contents in part or in whole. If you have received
> this message in error, please advise the sender by replying to this e-mail,
> and delete the message. Thank you.
>
>
>
> *From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org
> <re-wrenches-bounces at lists.re-wrenches.org>] *On Behalf Of *William Miller
> *Sent:* Monday, October 6, 2014 14:40
> *To:* RE-wrenches
> *Subject:* [RE-wrenches] TL inverter with long DC Feeder
>
>
>
> Wrenches:
>
>
>
> We are getting up to speed on using transformer-less inverters.  I have
> advocated long for the additional safety offered by these inverters but I
> am realizing the trade-offs with the new technology:  The implementation
> gets more complicated with the requirement for PV wire, OCPD and
> disconnecting means for plus and minus and plus providing  Arc Flash rated
> equipment.
>
>
>
> I am currently designing a system that will locate the PV about 400 feet
> from the residence.  The system will utilize 2 Solectria 5200 watt
> inverters at the residence.  I would like to provide disconnecting means
> for the 4 strings at the array, in case of any needed service or
> excavating.  Preferably I’d like the disconnecting means to be deployable
> by a lay person (i.e. the gardener).
>
>
>
> Finding an 8 pole, arc flash, 600 VDC rated disconnect is not easy.  I
> could install an Outback 8 circuit combiner with 8 touch-safe fuse
> holders.  The new combiners have had dead-fronts for a while now.  The
> gardener needs only to have a Philips screw driver to open this cover.  Any
> better ideas out there?
>
>
>
> Thanks,
>
>
>
> William
>
>
>
>
>
> [image: Gradient Cap_mini]
> Lic 773985
> millersolar.com <http://www.millersolar.com/>
> 805-438-5600
>
>
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> 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
>
> List-Archive:
> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>
>


-- 
Chris Mason
NABCEP Certified Solar PV Installer™
Solar Design Engineer
Generac Generators Industrial technician

www.cometsolar.com <http://www.cometenergysystems.com>
264.235.5670
869.662.5670
Skype: netconcepts
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20141006/78ab9135/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image005.jpg
Type: image/jpeg
Size: 4892 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20141006/78ab9135/attachment-0015.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.jpg
Type: image/jpeg
Size: 1460 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20141006/78ab9135/attachment-0016.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image006.jpg
Type: image/jpeg
Size: 1460 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20141006/78ab9135/attachment-0017.jpg>


More information about the RE-wrenches mailing list