Thanks all for the suggestions. Regarding the stacking, I read a little more into it. It seems like this is actually neither series or parallel stacking, since each inverter independently feeds its own 120V backed up loads panel. It will be interesting though to turn off one inverter and see if the issue continues, which would rule out a stacking concern.
Sounds like it will also be worth bypassing the GTI to see if that could be causing any issues. There is also no concern about limiting selling here. They do have utility approval for selling. Tump, you mention unplugging a cord/plug. Can you tell me a little more about what operation this would confirm? The system is not AC coupled. I'll report back with what I learn. Cheers, Dave *Dave Tedeyan, PE* Senior Engineer | Taitem Engineering, PC 110 South Albany Street | Ithaca, NY 14850 o. *607.277.1118 x121* f. 607.277.2119 www.taitem.com Solar • Sustainability • Energy • Design Certified B-Corporation since 2013 On Fri, Dec 20, 2019 at 6:01 PM Ray <r...@solarray.com> wrote: > The SWs were awesome for off grid in their day, but infamous for burning > up a couple of kW worth of array in inefficiency when grid tied. I > actually saw several systems that consumed more power from the grid than > they produced. Once the GTI box was added, it just got worse. I would > compare that system to an early 80s carbureted vehicle: partial design > solutions stacked on top of each other to meet emissions standards; then we > got computer controlled fuel injection. Nobody ever went back. I'd > suggest the same there: It never was a good GT solution. The equipment is > beyond its usable life anyway, time to upgrade. > > Ray Walters > Remote Solar > 303 505-8760 > > On 12/20/19 3:37 PM, Tump wrote: > > With this set up the AC feed *into* the grid is not constant. The current > will ramp up then back down. Open the connection end of the inverters and > you will see a small black (behind the cardboard) cord/plug that can be > disconnected to confirm operation & disable ramping effect. As long as the > inverters are connected to L1/L2 respectfully as individual inverters then > this should work. I do have the cable, but its really not the most > efficient AC coupling design out there. > The SWs still can be repaired using older boards but its pricy, there is > a market for them so you might be able to sell them and purchase something > a bit more up to date. I have the cable & a refurbished XW5548 contact me > off list if interested. Tump > > On Dec 20, 2019, at 2:18 PM, Lloyd Hoffstatter < > ll...@sunstruckconsulting.com> wrote: > > Dave, > > Guessing it’s a synchronization problem between the two inverters. > Depending on the placement of the grid tie breakers, the two inverters are > presenting themselves as either in parallel (2 x 120v sources on the same > leg) or “series” (120 / 240 on two 120V legs). > The attached manual excerpt and tech note talk about both. Seems that you > need a synch cable in either case, recently did a rebuild on an SW 5048 (pm > for internals rebuilder info) and needed cable to get both inverters to > work properly. > > Have at least one grid-tie / backup system that has been running for years > with dual SW / GTI’s – time for battery replacement, rest of system still > going… > > Best regards, > Lloyd > Lloyd Hoffstatter > Sunstruck Consulting > > Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for > Windows 10 > > *From: *Dave Tedeyan <dtede...@taitem.com> > *Sent: *Friday, December 20, 2019 1:03 PM > *To: *offgridso...@sti.net; RE-wrenches > <re-wrenches@lists.re-wrenches.org> > *Subject: *Re: [RE-wrenches] Xantrex SW 4048 grid tie mystery > > Dave, > Sorry, misspeak on my part. It is DC negatives and grounds that are tied > together. No neutrals in the DC box. > Cheers, > Dave > > *Dave Tedeyan, PE* > Senior Engineer | Taitem Engineering, PC > 110 South Albany Street | Ithaca, NY 14850 > o. *607.277.1118 x121* f. 607.277.2119 > www.taitem.com > > Solar • Sustainability • Energy • Design > Certified B-Corporation since 2013 > > > On Fri, Dec 20, 2019 at 12:57 PM Dave Angelini Offgrid Solar < > offgridso...@sti.net> wrote: > > Why would neutral be in the DC conduit box? This just wrong but I doubt > this is the problem. > > Since this never worked properly or has not in 13 years, I would suggest > replacement with modern equipment. SW from xantrex has been out of support > for around 15 years and always was a headache grid tied, in my opinion. > > *Dave Angelini Offgrid Solar* > > *"we go where powerlines don't"* > > *http://members.sti.net/offgridsolar/ <http://members.sti.net/offgridsolar/>* > > *e-mail offgridso...@sti.net <offgridso...@sti.net>* > > *text 209 813 0060* > > On Fri, 20 Dec 2019 12:44:42 -0500, Dave Tedeyan <dtede...@taitem.com> > wrote: > > Hi All, > > I am someone's last ditch effort to get their system working which has > been non-functional since a few months after installation, 13 years ago... > > After getting some new batteries in there, I can at least fire it up. It > is a grid tie with battery backup situation with two Xantrex SW4048 > inverters. Each inverter is kind of like its own system with two Outback > MX60 CC's per inverter, and each inverter powers its own 120V backed up > loads panel. They do not see each other until their 60A single pole > breakers in the main panel. > > What seems to be happening is that after turning on the inverters the AC1 > in good light will flash for about 30 seconds, then it syncs up to the grid > and the light stays on solid. But then after a little bit, that light will > start flashing, indicating that the utility power has been dropped, when it > has not actually been dropped. Then at some point the backed up loads would > lose power. The customer says that every 1-10 minutes, they would lose the > backed up loads for 10-90 seconds. This happened all night long until they > bypassed the inverters. > > There are a few other things of note: > 1. There is a Xantrex GTI for each inverter. > 2. I see in the manual there is information about stacking the inverters, > but I am guessing in this setup this not necessary or would even be counter > productive to stack the inverters. Not sure if the inverters not being > stacked could cause one of them to unsync with the utility? > 3. Neutrals and grounds are bonded in their main panel, but also in each > of the Xantrex DC breaker boxes. I was going to separate them in the DC > breaker boxes, but found that there is no way to isolate the battery > negative bus from the box itself, and figured it would be dodgy to unground > the enclosure. So I am also not sure if the multiple N-G bonds could be > causing these issues. > > Does anyone have any ideas? > Cheers, > Dave > > *Dave Tedeyan, PE* > Senior Engineer | Taitem Engineering, PC > <5DD17443B6814684BEA5BA6A3C5C2E3A.gif> > 110 South Albany Street | Ithaca, NY 14850 > o. *607.277.1118 x121* f. 607.277.2119 > www.taitem.com > > Solar • Sustainability • Energy • Design > Certified B-Corporation since 2013 > > -- > > > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@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 > > <SW Series Manual on multiple inverters.pdf><SWI PARALLEL SERIES Stacking > cable instructions.pdf>_______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@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 > > > *t...@swnl.net* *www.SWNL.net* > Solarwinds Northernlights > * Serving Mid Coast Maine & Northern California* > * 207-832-7574 Cl. > 610-517-8401 * > *Blair "TUMP" May* > > > * ******** MAINE'S CHARTER ******** * * > NABCEP "Certified PV Installer"* > > > * ******** MAINE'S CHARTER ******** ** > Trace Xantrex "Certified" Dealer / Installer"* > > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@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 > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@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 > >
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