Generac Transfer Switch w/ Solar?

[ryangittens]

Does anyone know if a generac ATS can be used with solar instead of a generac geneerator?

From my understanding the generator provides a signal to the ATS and I was wondering if there was anyway to bypass that and have it switch over to another source that isn't necessarily a generator.

 

[jaggedben]

I believe those ATS are designed to switch over to the backup source only when they see a signal from the generator. So you may have to figure out how to provide the ATS that signal from the solar source when the grid goes down. Their ATSs are designed to interface with their generators which have features compatible with the ATS. If you can emulate those features the ATS won't know the difference. I don't know if it affect warranty.

That said... WHY? Wouldn't you want to use the solar all the time? Generally speaking you'd want to the solar as an interconnected system with an MID and any backed up loads behind the MID.

 

[ggunn]

I believe those ATS are designed to switch over to the backup source only when they see a signal from the generator.

That is correct; the Generac ATS doesn't switch over until the generator tells it that it is up to speed and stable. There are other AT switches that respond to the 60Hz AC going away, though.

 

[hillbilly1]

The older Generac transferswitches are “dumb” switches. The generator has the brains, and sends 12 vdc to a relay, and if the emergency feed is live, it transfers. Don’t know about the newer Generac switches.

 

[ryangittens]

@jaggedben Here is a line diagram. Their documentation show a mechanical interlock where the T1 Gateway is shown but we'd like it to transfer automatically. Each manufacturer seems to have their own MID and these guys don't have one for this application so that's where the transfer switch came in.

 

[ryangittens]

The older Generac transferswitches are “dumb” switches. The generator has the brains, and sends 12 vdc to a relay, and if the emergency feed is live, it transfers. Don’t know about the newer Generac switches.

If it's just a 12V signal that should be easy enough to simulate.

 

[BackCountry]

Does anyone know if a generac ATS can be used with solar instead of a generac geneerator?

From my understanding the generator provides a signal to the ATS and I was wondering if there was anyway to bypass that and have it switch over to another source that isn't necessarily a generator.

I suppose you could try — it would be fairly unstable though. Alternatively, you could do sunlight backup with an Enphase IQ System Controller which is designed for that purpose. I don’t really care for how it works and I don’t think it’s stable, but it can be done.

Throw one battery into the mix and then it becomes very stable.

 

[jaggedben]

His line diagram has batteries. I google the inverter and its a Darfon, and the Darfon website says the T1 is an ATS. So I don't understand the issue.

 

[BackCountry]

His line diagram has batteries. I google the inverter and its a Darfon, and the Darfon website says the T1 is an ATS. So I don't understand the issue.

I didn’t see the SLD, just read Darfon’s documentation for the T1 gateway and I don’t get it either, it’s automatic

 

[ryangittens]

@jaggedben @BackCountry these guy's documentation isn't the best. The T1 was designed to work with their H7 inverter which I believe is their second generation of inverters.

They were the ones who actually said the generac could be used as others had done it this way, I just don't see how.

 

[jaggedben]

Seems like they oughta be able to tell you more. (And if not, I wouldn't install products that don't offer that level of support myself. What're you gonna do when it doesn't work?) Sorry I'm not a Generac installer so I can't confirm if the ATS merely needs 12V and that's all. Maybe someone else here can.

 

[ggunn]

@jaggedben @BackCountry these guy's documentation isn't the best. The T1 was designed to work with their H7 inverter which I believe is their second generation of inverters.

They were the ones who actually said the generac could be used as others had done it this way, I just don't see how.

With a power supply and a relay you could probably emulate the signal that the generator produces to tell the ATS to switch inputs, but it would likely void the ATS warranty.

 

[jaggedben]

With a power supply and a relay you could probably emulate the signal that the generator produces to tell the ATS to switch inputs, but it would likely void the ATS warranty.

I wouldn't brother trying unless I can get confirmation the signal is merely a voltage.

 

[ggunn]

I wouldn't brother trying unless I can get confirmation the signal is merely a voltage.

I am virtually certain that it is. At least it was 14 years ago or so when I was teaching a lab with a Sunny Island, a Sunny Boy, and a Generac generator and ATS.

 

[ryangittens]

Sounds like a cool experiment. I'll let you guys know if it works

 

[hillbilly1]

It would cost more, but you could use an ASCO 185 series transferswitch. It’s a bare bones switch that is fully automatic. If primary (preferred) source is lost, it will give a signal (which you don’t need) for the secondary source to come on line, then after a delay, if the source is good, transfers. When the primary source comes back on line, after a time delay, it switches back. No control wiring needed.

ASCO 185 Series 200A1Ø-120/240V 3 Wire Automatic Transfer Switch

D185 A2 200 F4M​

 

[hillbilly1]

ASCO 185 Series 200A 1ph 2 Pole Open Transition Automatic Transfer Switch

Your ASCO Superatore. ASCO 185 Series 200A 1ph 2 Pole Open Transition Automatic Transfer Switch. In Stock, Free Shipping, No Tax. Best Price - Will Not Be Undersold. Free Tech Support

apelectric.com

 

[hillbilly1]

I have modified the controls on one of these to work as a slave. I think I had to use two time delay relays to make it work with a non-Generac generator. The ASCO is much easier though, and better quality.

https://www.northerntool.com/products/generac-service-entrance-rated-automatic-transfer-switch-200-amps-120-240-volts-single-phase-model-rxsw200a3-37850

 

[ryangittens]

It would cost more, but you could use an ASCO 185 series transferswitch. It’s a bare bones switch that is fully automatic. If primary (preferred) source is lost, it will give a signal (which you don’t need) for the secondary source to come on line, then after a delay, if the source is good, transfers. When the primary source comes back on line, after a time delay, it switches back. No control wiring needed.

ASCO 185 Series 200A1Ø-120/240V 3 Wire Automatic Transfer Switch

D185 A2 200 F4M​

Looks like this is exactly what we need! Thanks for sharing @hillbilly1

 

[rainwater01]

It might be late but the Generac solar version uses a 12 volt cat 5 signal between the inverter and transfer switch to actuate the line voltage relay in the transfer switch. I set one up once with a line voltage time delay relay in the transfer switch that would transfer instantly when the grid power drops but delays when it comes back on.


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