Sol-Ark calls for larger generators to be installed at the grid lugs. I always assumed that was a sizing/ampacity issue and it likely still is but I wonder now if there was some desire to use in this "whole house generator" configuration, too?
Lots of questions. Sol-Ark: you on here? Howard "Scot" Arey Owner, Solar CenTex 254-300-1228 ________________________________ From: RE-Wrenches <[email protected]> on behalf of Jay <[email protected]> Sent: Monday, October 19, 2026 6:31 PM To: [email protected] <[email protected]> Subject: Re: [Re-wrenches] Sol-Ark for 400-amp service; help me understand this whole-house generation diagram I agree why wouldn’t you install the generator at the Gen input? Ok if you’ve got a ac couple then that eats up the Gen input. But yeah brings up a lot of questions as to integration. Here is another. Does the sol ark know to reduce the charge rate if the generator is not as big as the grid which I would expect? Makes the case for multiple sets of CT’s to measure and allow for control. I’ll be curious what others think/know Jay On Oct 19, 2026, at 4:10 PM, [email protected] wrote: So I've always been of mindset that solar integrated downstream (customer-side) of a whole-house generator was a backfeeding debacle to avoid as a solar inverter had no means to backfeed into a generator as there is no grid to export excess solar production too. So while researching a possible method I come across the SolArk schematic for integration to whole house generator integration and even though my eyes have gone across it dozens of times, this was first time I really LOOKED at it. Was shocked to see the whole house generator upstream of the inverter. Seems to me that one only wants an inverter with a whole-house generator if you want the solar and the battery's energy management features. The always excellent SolArk tech said in this config the inverter knows the gen is on via the 2-wire start wires; this was eye opening to me as I had a paradigm this was only a relay to trigger the gen on and I never considered the two-way communication part. The CT's at the transfer switch would measure gen output and I suppose the inverter will "know" that output via the associate CT wires. So my questions are: * Why would we ever want the inverter to produce during a grid outage when the gen is running? * If the gen power was "clean enough" that the inverter kept on making power, is the SolArk truly "know" via the 2-wire start that the gen is on and to not make (any?) power? * Would the SolArk try to make power to offset the power of the Gen and reduce that to zero or does that functionality go away because the SolArk knows the gen is on? And the final question: If the SolArk is in this configuration only to provide energy management (since the whole-house gen is providing whole house backup) can I put this schematic in place on a house where there is a 400A service and two 200A panels but since I'm wanting to retain the whole house gen backup but also want the ESS energy management, one SolArk 18 provides that in this config on just one of the panels: I have the whole house backup but using battery power from one inverter to meet energy management needs. Been doing this for almost 14 years and for some reason, this schematic nearly fried my brain to mush... Any thoughts or inside or knowledge you can share? PPS - one more question - this helps me AC couple a Fronius 12.5 onto the GEN inputs, too and 'solves' the quandary I was having. <image.png> Howard "Scot" Arey Owner, Solar CenTex NABCEP PV Installation Professional TECL 29755 254-300-1228 <image.png> _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: [email protected] Change listserver email address & settings: https://lists.re-wrenches.org/mailman/options/re-wrenches_lists.re-wrenches.org/ There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/[email protected]/ https://lists.re-wrenches.org/pipermail/re-wrenches_lists.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: [email protected] Change listserver email address & settings: https://lists.re-wrenches.org/mailman/options/re-wrenches_lists.re-wrenches.org/ There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/[email protected]/ https://lists.re-wrenches.org/pipermail/re-wrenches_lists.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
