Sherwooddavid
Honeywell 20kw Model G0070642
200 amp transfer switch RXSW200A3CULH

I'm thinking about installing a new solar system and wondering if my generator will cause any problems ?
I know the the solar system will shut down if the utility power goes out but wondering if there is an auxiliary contact or something that stops the solar system from coming back on when the generator starts ? Thanks
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murphy
If the solar system is grid tied it connects just after the power company meter (s).  My power company requires an inbound and an outbound meter.  That point is then fed to the power company side of the switch.  When power fails the solar system shuts down and the generator detects the loss of power.  It starts up an throws the switch to connect the generator to the house.  The power company and the solar panels are disconnected.  Under no circumstances do you want the panels feeding into the generator.  That will destroy the generator.
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Sherwooddavid
Thanks murphy,yes the system is grid tied and up here in Canada there is only 1 net meter they install.
I'm hoping the solar installers know what their doing and have dealt with houses before that have standby generators.
No I agree don't want the panels feeding the generator...paid too much for it !
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BillM
I'm in the process of installing Tesla Powerwalls and 18 Suniva 340W Solar Panels (OPT340-72-4-100).  The Powerwalls are going before the ATS.  I also have, now, the dual meter setup.  My generator is after the Powerwall and after the Solar.  The generator will only kick on if the Powerwall depletes it's charge.  Now, in the Tesla preferred design, the Powerwall setup will run your house for a full 7 days off grid.  Since I have a generator, I'm not concerned about getting 7 days out of it.  My goal is to reduce my WE-Energies utility bill to zero'ish.  I don't care about excess energy getting sold back.  I won't say no to that, but that's not in the scope of the project.  
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JayH

By design, grid-tied inverters are rather fussy about the frequency of the power line and will shut down unless there is power at the right voltage very close to 60 cycles (50 in some parts of the world) and stable for several minutes. So, if the sun is shining and the power fails, the solar inverter will shut down immediately.

There is a minimal risk in some specific scenarios. Depending on a number of factors, the solar panels may or may not try to augment the generator during a daytime power outage. A 20KW generator probably uses a whole-house transfer switch. If the solar panels are tied to the load center behind the transfer switch as opposed to a separate panel or meter on the utility side of the switch, and the generator's frequency is close enough to 60 Hertz, the solar inverter may see the generator as if it is the utility and activate. This would result in the solar panels producing power in phase with the generator and the load. It's possible that this could cause issues if the panels produce more energy than the load is consuming, in which case the solar output could possibly try to turn the generator as a motor and cause it to speed up, then go out of tolerance for the inverter which will disconnect, then repeat every few minutes.

There's an unused microswitch in the transfer switch that could be wired as a dry contact to the solar inverter to inhibit it during a power outage if this is an issue. Alternatavely a service-rated panel could be used to connect the solar system to the utility side of the transfer switch. 

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garrybrowns
I've had my 4kw system for 6 years now and it's paid for itself 3 times over. I haven't had a power bill since it was installed. Recommend this review https://websolarguide.com/bifacial-solar-panels/
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grsthegreat
garrybrowns wrote:
I've had my 4kw system for 6 years now and it's paid for itself 3 times over. I haven't had a power bill since it was installed.
what did your system cost, installed. It doesnt seam like a 4kw can power an entire house. A 4 kw generator wont power much.
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Sherwooddavid
garrybrowns wrote:
I've had my 4kw system for 6 years now and it's paid for itself 3 times over. I haven't had a power bill since it was installed.


That's good to hear Garry. I'm in the process of installing a 13.1 kwdc (32 panels x 410 w) system that can produce enough to take care of most of my power bill. I just have to figure out a way to ensure its locked out when the Generac is running during an outage. Some people say the inverters won't run on generator power but I can't take the chance.
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murphy


That's good to hear Garry. I'm in the process of installing a 13.1 kwdc (32 panels x 410 w) system that can produce enough to take care of most of my power bill. I just have to figure out a way to ensure its locked out when the Generac is running during an outage. Some people say the inverters won't run on generator power but I can't take the chance.

Did you read my post immediately after your original post?  I have 10 kW of panels and a 20 kW generator.  The two devices never see each other.  No special equipment required.
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Brian Baughman
With a Generac PWRcell System, the generator will be able to be ac-coupled to the PWRcell inverter through the PWRcell ATS.  For any other PV or ESS system the generator will have to be 100% isolated from the inverter output circuit conductors.
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BillM


That's good to hear Garry. I'm in the process of installing a 13.1 kwdc (32 panels x 410 w) system that can produce enough to take care of most of my power bill. I just have to figure out a way to ensure its locked out when the Generac is running during an outage. Some people say the inverters won't run on generator power but I can't take the chance.


That sounds like a great system.  I couldn't afford the premium of those 410w panels so I just went live with 18 panels x 360 w and two Tesla Powerwalls.  I am all wired for a 3rd Powerwall and another bank of 18 panels.  My solar is ground installed about 200 feet east of my house.  I also have a Generac 22kW Guardian.  I'm hoping to go to a net zero electric bill eventually.  Right now, my EV is ruining my plan and I am fairly ok with that.
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