ceb58
Senior Member
- Location
- Raeford, NC
Has any one had any experience with Generac's PWR transfer switch using the solar as the emergency backup source? Question is mainly the wiring between the inverter and ATS.
solar ATS
- Thread starter ceb58
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Coppersmith
Senior Member
- Location
- Tampa, FL, USA
- Occupation
- Electrical Contractor
You would have to use a solar system designed for off-grid usage. Most solar systems are designed to work in tandem with utility power and automatically shut-off when no utility power is available. This keeps them from backfeeding utility lines which endangers line workers. If you used such an off-grid system, it would be generating all the time, but you would not be able to utilize that power unless there was a utility failure (or unless you have some really fancy switching arrangement).
Assuming you still want to use an off-grid solar system as emergency power, then just wire the output of the inverter to where the generator normally goes on the ATS. Since the solar is generating all the time, no startup or shutdown signals are required. You would need a battery system on the solar side to handle an outage after dark (or even past the peak). Your solar system would be required to handle all the load or load shed.
Assuming you still want to use an off-grid solar system as emergency power, then just wire the output of the inverter to where the generator normally goes on the ATS. Since the solar is generating all the time, no startup or shutdown signals are required. You would need a battery system on the solar side to handle an outage after dark (or even past the peak). Your solar system would be required to handle all the load or load shed.
Last edited:
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
Isn't this a bit rare? Are there really inverters that can load follow in real time without an energy storage system?
Coppersmith
Senior Member
- Location
- Tampa, FL, USA
- Occupation
- Electrical Contractor
The inverter would not load follow. It would just produce as much power as it could based on the input. A battery (energy storage) system is required to meet the load requirements since solar systems only produce peak power for a few hours per day (and zero power at night).
ceb58
Senior Member
- Location
- Raeford, NC
This is the way the system is wired
normal utility coming in on N1 N2 to the transfer switch, inverter feed, with battery bank tapped off of N1 N2, protected load feed from inverter to E1 E2 of transfer switch and T1 T2 to main distribution panel. Under normal situation solar would back feed grid for credit. Under emergency solar would feed house only.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Sounds kind of okay within the vagueness of your description. Please clarify that the inverter has two AC connection points, one being a grid side feed (connected on line side of transfer switch) and the other a protected loads side connected to E1 E2 like you said. Personally I think that doing it this way is kinda Rube-Goldberg and I think it's confusing to the installer than the inverter provides a 'backdoor' to the grid that bypasses the transfer switch. Also if it is not sold as a complete solution it may not meet the requirements of 705.170(2) that micro-grid interconnect devices be listed. But I've seen it as a manufacture recommended method.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Any off-grid capable inverter can load follow in real time as long as there is enough solar power available to supply the load. The battery is mainly there to provide for when the solar isn't available, not to enable load following. To a certain degree the inverter does not know or care what DC source is providing the power to load follow.
BillK-AZ
Senior Member
- Location
- Mesa Arizona
Consider the SolarEdge StorEdge system that has a limited standalone capability for a critical loads subpanel. Added benefit of being able to utilize the battery for peak demand shaving and transferring energy from low value periods to high value periods. There is a requirement regarding shared neutrals, the subpanel neutral must connect only to the provided terminal in the SolarEdge transfer switch. Support for a generator, but only for the subpanel loads.
www.solaredge.com
Powering People’s Lives Around the World | SolarEdge
Turn your businesses and homes into a sustainable energy hub with a SolarEdge inverter solution and the SolarEdge energy manager platform.
We have done this a with a sunny island, and a 48V battery bank.
The sunny island is a second inverter besides the grid tie one.
www.sma-america.com
I cant remember if the sunny island can work with any brand of grid tie.
If I recall correctly there was another system I have seen that had an outback inverter that could dual function and has a outback branded transfer switch.
The sunny island is a second inverter besides the grid tie one.
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If I recall correctly there was another system I have seen that had an outback inverter that could dual function and has a outback branded transfer switch.
rainwater01
Member
- Location
- Greenwood Indiana
- Occupation
- Electrician
I will be soon. Are you doing the whole generac pwrcell system?
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Did you take their pwecell sales and installation class?
How are they delivering the class?
rainwater01
Member
- Location
- Greenwood Indiana
- Occupation
- Electrician
Yeah. It’s a full one day livestream. All the manuals are available online. It looks pretty easy to install.
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