[RE-wrenches] ATS models to bypass GT hybrid inverters for maintenance/faults

Tue Jan 14 12:24:42 PST 2025

I would also add that the Generac ATS is not made for this application, 
it is made to work with their generators only.  It connects to the 
generator control board for its voltage sensing, etc.  It can be "hot 
wired" to work with solar, but I had to add a small battery ( for 12 v 
power) and a small charger to make it work, and meanwhile Generac is NOT 
helpful for installers outside their network.  I couldn't even get good 
info on what the different terminals of the ATS control did.

2nd, I agree with William that AIO inverters are not ready for off grid 
applications, because of the numerous "safety" features that take out 
the entire house with any fault.  I think if I did use one for off grid, 
I'd probably put the array on its own separate charge controller.  AIO 
is yet another product that seems at first like a good idea, but in 
terms of reliability for off grid is not.   The touch screen programming 
of Solark for instance, at first seemed like a huge improvement, but 
when the inverter shuts off or does other weird things, then you realize 
that you can't count on it at all.  Too many settings are strangely 
hidden in other menus, that can completely make the system not behave 
like it should.  Just shows you how much wisdom folks like Bob Gudgel 
(RIP) had working on the old Trace stuff. The old SWs mostly did what 
you expected, and kept us in business all these years.

Solark needs a complete redo on their software/ firmware, to be viable 
for off grid.

I'm about to try Midnite's new AIO for a backup situation, so maybe I'll 
change my mind for their use in off grid applications.

Ray Walters
Remote Solar

On 1/14/2025 12:36 PM, William Miller via RE-wrenches wrote:
>
> Stuart:
>
> I understand the concern and appreciate the consideration to provide 
> more reliability.  The approach you suggested sounds like a band-aid, 
> not a cure.
>
> I do not know if this complete shutdown is required by the listing (a 
> feature) or is just a bug.  Does anyone have information on this?  If 
> it is not required, the manufacturers should certainly correct these 
> problems.
>
> This may be a case against All-in-on inverters.  If there is a PV arc 
> fault on systems with separate charge controllers the inverter will 
> not curtail operation and it’s pass-through capabilities.
>
> William Miller
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com <http://www.millersolar.com/>
>
> CA Lic. 773985
>
> *From:*RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] 
> *On Behalf Of *Stuart Kriendler via RE-wrenches
> *Sent:* Tuesday, January 14, 2025 11:09 AM
> *To:* re-wrenches at lists.re-wrenches.org
> *Cc:* Stuart Kriendler
> *Subject:* [RE-wrenches] ATS models to bypass GT hybrid inverters for 
> maintenance/faults
>
> Good day Wrenches,
>
> 2025 looks to be the year for installing more grid tied (GT) battery 
> back up hybrid inverters on new and existing GT PV systems in a whole 
> house backup scenario
>
> i.e. Utility - Hybrid Inverter - House Loads
>
> With these newer GT hybrids so 'sensitive', any fault on the PV side 
> can cause them to shut down, thus stopping power to the house.
>
> To minimise this it seems sensible to add an ATS to the system such 
> that if/when the hybrid faults, the ATS w switch to grid power, bypass 
> the hybrid, and power the house.
>
> This could save an emergency truck roll or late night phone call for 
> installers.
>
> Anyone have experience on good value-for-money Listed automatic 
> transfer switches that would do the job, 200A, 120/240V?
>
> Two name brand options that came up on the less expensive end of the 
> spectrum are:
>
> - Generac 
> RXSW200A3 (https://www.generac.com/residential-products/standby-generator-transfer-switches/automatic/rxsw200a3/)
>
> - *Kohler 200-amp, Service Entrance RXT ATS | 
> RXT-JFNC-200ASEQS4 (*https://www.kohler.com/content/dam/kohler-com-NA/Lifestyle/PDF/PDF-g11152.pdf)
>
> However, they each say their ATSs must be used with the corresponding 
> generator.
>
> I would imagine a simple 'grid sense' functionality would mean that if 
> the hybrid's output was connected to the Grid/Normal lugs and the grid 
> was connected to the Gene/Backup lugs in the ATS it should work.
>
> However I don't want to end up with an expensive surprise in a 
> relatively remote location where I operate!
>
> Would appreciate any feedback with experience with the above or other 
> ATS models or how people are future proofing for this scenario?
> To do future maintenance/torque checks etc. in a GT hybrid whole home 
> backup situation, it would be nice to bypass the inverter and keep the 
> house powered for safety and homeowner convenience in general.
>
> Thanks and best.
>
> Sunniest regards,
>
> Stuart
>
> 441 599 2105
>
>
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