Mains Power Backup

Discussion about OutBack Inverters in Off Grid Applications

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linedadelas
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Joined: Fri Feb 14, 2020 12:02 am

Mains Power Backup

Post by linedadelas » Fri Feb 14, 2020 12:04 am

I am electrically ignorant. I have a Flexpower one system installed in my house. I have access to a reliable mains electricity source. The solar power supplies all my energy-saving lighting needs, while the mains power supplies heavy-duty needs. My system was stalled by a local agent for OutBack.

Reading the Manual, I see:
"On-Grid Applications
In on-grid applications, the FLEXpower ONE can use the grid power as the primary power source or as the backup source of power... If the FLEXpower ONE is used as the primary source, the grid power will be used when the batteries have been drained. In this situation, the AC power or PV harvest can be used to recharge the battery bank."

That sounds simple. But my installer has set up a manual system where I have to monitor the battery level and then flip a whole series of switches (according to instructions he left) if the battery level runs too low.

Doesn't the Flexpower 1 one do that automatically if correctly wired? Is there any reason he would have made it manual?

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
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Re: Mains Power Backup

Post by raysun » Fri Feb 14, 2020 9:46 am

There are lots of ways to integrate a battery storage/inverter power system into a home.

To concisely answer your question would require a good deal more information about the system components, and an understanding of the as-built wiring.

Look at other users' profiles to get an understanding of the information that is listed there and is helpful for others to give cogent responses.

In the end, any modification of the system will require your installer/electrician be involved. It may be illuminating for you to pass on the information you shared here, and ask them the same question.

Very generally, all the Outback systems designed for grid-tie have the "smarts" to automatically manage battery charging, and consumption, from both solar and grid.

fcwlp
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My RE system: GS8048A, FM80 w/3,600 W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed
I also install and maintain grid-tied and off-grid systems, details will be given for these system if required
Location: 80 miles NE of Phoenix at 5500'

Re: Mains Power Backup

Post by fcwlp » Fri Feb 14, 2020 2:25 pm

linedadelas wrote:
Fri Feb 14, 2020 12:04 am
That sounds simple. But my installer has set up a manual system where I have to monitor the battery level and then flip a whole series of switches (according to instructions he left) if the battery level runs too low.

Doesn't the Flexpower 1 one do that automatically if correctly wired? Is there any reason he would have made it manual?
In addition to what raysun requested. A Flexpower one can operate in seven different modes, each mode with a different functionality. A Flexpower one includes the Mate3s controller and FNDC and has the capability to monitor the battery voltage and seamlessly control grid use w/o your involvement or flipping of breakers. Since you have only a 120V system it sounds like you are not selling back to the grid and just powering critical loads.

A couple of additional questions:
- What is your goal with this system?
- What is your utility plan?
- Are there different rates at different times of day?
- Do you have a peak rate charge?
- Do you have or can you get the design schematic and upload it?
- Pictures can help.

I have one grid-tied customer who is on a plan with a peak rate charge who is a frugal electricity user. The month before they went on solar, only 61 kwH were used during the 120 on-peak hours but there was one hour were 6.8 kW was used. Peak rate charge was 6.8 * $14 or $95. In the on-peak hours they are now using primarily the batteries in the mini-grid mode and are running a max of 0.1 kWh from the grid. Other customers on different rate plans have different strategies for the mode used.

I would suggest that you also get your OpticsRE setup. It is simple to do and gives you better visibility into the system and allows the Outback staff to view and suggest changes.

fcwlp
Forum Guru
Posts: 204
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600 W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed
I also install and maintain grid-tied and off-grid systems, details will be given for these system if required
Location: 80 miles NE of Phoenix at 5500'

Re: Mains Power Backup

Post by fcwlp » Fri Feb 14, 2020 2:34 pm

linedadelas wrote:
Fri Feb 14, 2020 12:04 am
That sounds simple. But my installer has set up a manual system where I have to monitor the battery level and then flip a whole series of switches (according to instructions he left) if the battery level runs too low.
Are these switches (most likely breakers) in your AC panel or on the Flexpower One itself. Include a copy of the instructions, but blank out his name if on it.

Mike Curran
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My RE system: Outback - Garage roof:
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All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Mains Power Backup

Post by Mike Curran » Sat Feb 15, 2020 4:40 am

Doesn't the Flexpower 1 one do that automatically if correctly wired? Is there any reason he would have made it manual?
If your lighting circuits are fed from the mains panel along with your "heavy duty" loads, that might explain why you have to flip so many switches to charge your battery.

When your PV system isn't big enough to support all your loads, as sounds like the case for you, normally the circuits that you want fed from your battery are wired from a separate "backed-up loads" panel that's dedicated just to those loads. In your case, sounds like that would be your lighting loads. This backup panel would be fed from your Flexpower 1 AC output, and the FP1 would also have an AC input feed from the grid. Wired in this manner, your FP1 will be able to automatically recharge your battery when the need arises.

There's more to this than is easily described without drawing a one line wiring diagram, such as incorporating a bypass to allow the backup panel to be fed from the grid if/when your FP1 needs service. You should talk with your electrician about what can be done to add a backed up loads panel to your system, if that sounds like what you're after. - Mike
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

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