[RE-wrenches] Will IQ8 microinverters backfeed a generator during grid interruptions

[scot.arey at solarcentex.com]

Generac.

I thought that load shed function was based on frequency downward deviation caused by heavy loads so perhaps this might cut solar at the only theoretically possible point where solar might be acceptable: high loads.

I'm at the point thinking what I tell folks all the time: don't interconnect solar downstream of the generator ATS. Sigh...was trying to minimize costs to customer in this post-tax credit world but these pesky generators.

Howard "Scot" Arey
Owner, Solar CenTex
254-300-1228

________________________________
From: RE-wrenches <re-wrenches-bounces at lists.re-wrenches.org> on behalf of Mac Lewis via RE-wrenches <re-wrenches at lists.re-wrenches.org>
Sent: Thursday, January 22, 2026 7:35 AM
To: offgridsolar at sti.net <offgridsolar at sti.net>; RE-wrenches <re-wrenches at lists.re-wrenches.org>
Cc: Mac Lewis <maclewis1 at gmail.com>
Subject: Re: [RE-wrenches] Will IQ8 microinverters backfeed a generator during grid interruptions

Hello Scot,

What type of generator?

Generac has a load shed module that can shed a load remotely by "knowing" when the generator is providing voltage.  Small dip switches can be set to completely lock out the load when running on generator voltage.  Generac Smart management module is the product name.  There are also another product from PSP called the  SAK-60 that supposedly can do this with any generator type (no direct experience with this).





On Wed, Jan 21, 2026 at 3:01 PM Dave Angelini Offgrid Solar via RE-wrenches <re-wrenches at lists.re-wrenches.org<mailto:re-wrenches at lists.re-wrenches.org>> wrote:
And in this case, with all the Ice storm doom and gloom coming, to alot of the country, inform your users how to turn off their array and run a generator safely!

Offgrid is just so much easier sometimes.

 😉

Dave Angelini Offgrid Solar
"we go where powerlines don't"
  <http://members.sti.net/offgridsolar/> https://offgridsolar1.com/ <http://members.sti.net/offgridsolar/>
e-mail  offgridsolar at sti.net<mailto:offgridsolar at sti.net>
text 209 813 0060


On 2026-01-21 12:55 pm, Zeke Yewdall via RE-wrenches wrote:

In that case, we're getting way off track and way more complicated :P

Just put a contactor between the PV array and the POI using the NC contacts, with the coil powered off the generator.  Then the PV array can never backfeed the generator because it'll be turned off anytime the generator is running.

Zeke

------------------


Thanks but I'm just trying to grid-tie a small Enphase array without ESS where the point of interconnection is on the customer side of the generator/ATS.

Trying to use existing wires in place to simplify and lower costs...but the generator is my constraint because I need the PoI to be on line side of the ATS.

Howard "Scot" Arey
Owner, Solar CenTex
254-300-1228



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--



Mac Lewis


"Yo solo sé que no sé nada." -Sócrates
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