Batteries hit 50.8V for the first time and system used generator instead of the grid.

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CFTX
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Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by CFTX »

I have my system (Flex Power 8 kW) running in Grid Zero mode from 18:00 to 10:00. After that it goes into Grid Tied mode from 10:00 to 18:00. We have had several rainy days this week and my Simpliphis hit 50.8 for the first time. The system ran the generator for 15 minutes rather than going to the grid.

1. Is there a setting I need to change to get off the batteries before the AGS voltage threshold?
2. What logic did it use to turn off the generator?

Battery Voltage below 2 minute start voltage. Automatic Generator Start (AGS) Started. Measured Battery Voltage 50.8 VDC.

Thank you!
fcwlp
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My RE system: GS8048A, FM80 w/3,600W 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 install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by fcwlp »

You state your system is a FlexPower 8048. Answers are based on Radian inverter, which is what I believe you have.
CFTX wrote: Wed Jan 24, 2024 8:48 am 1. Is there a setting I need to change to get off the batteries before the AGS voltage threshold?
If the system was in Grid Zero when this happened, in OpticsRE go to Inverter -> Battery Charging and at the bottom of the page, change "Grid Zero DOD Volts" to something greater than your AGS start voltages.
.
CFTX wrote: Wed Jan 24, 2024 8:48 am 2. What logic did it use to turn off the generator?
Should be what every you have programmed in the Radian's Battery Charging parameters and/or the FNDC's Battery Charging parameters. [edit, see below. For 2-min start stop is based on FNDC.]
Last edited by fcwlp on Thu Jan 25, 2024 7:46 am, edited 1 time in total.
CFTX
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Posts: 4
Joined: Fri Dec 08, 2023 6:20 am
My RE system: Outback FlexPower 8048
6.x kW of Solar
10 kW Generator
Grid Zero/Grid Tied

Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by CFTX »

Grid Zero DOD Volts was set to 50.8. I set that to 51.2. I guess that means that the system will switch to grid when the batteries get to 51.2V, and the generator will kick on if the grid is down and the batteries get to 50.4V.

This is the 2 minute start voltage. It is 50.4. If Grid Zero DOD Volts was set to 50.8, I'm not sure why the generator came on.
Screenshot 2024-01-25 082154.png
Also,

I don't see what setting turns the generator off when the start is based off of a low voltage command. One would think it would be some higher voltage threshold.
fcwlp
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Posts: 1286
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600W 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 install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by fcwlp »

CFTX wrote: Thu Jan 25, 2024 6:23 am Grid Zero DOD Volts was set to 50.8. I set that to 51.2. I guess that means that the system will switch to grid when the batteries get to 51.2V, and the generator will kick on if the grid is down and the batteries get to 50.4V.

This is the 2 minute start voltage. It is 50.4. If Grid Zero DOD Volts was set to 50.8, I'm not sure why the generator came on. Read the manuals on how to calibrate voltages. If the FNDC is off there is an app note if you have to calibrate the FNDC to actual battery voltage. https://outbackpower.com/downloads/docu ... p_note.pdf
You could have a difference in voltage calibration between the inverter and the FNDC which supplies the voltage reference to the Mate3S for AGS function.
CFTX wrote: Thu Jan 25, 2024 6:23 am I don't see what setting turns the generator off when the start is based off of a low voltage command. One would think it would be some higher voltage threshold.
Read at least p. 33 and study table that describes start and stop reason. I was wrong on my first answer, after a 2 min AGS it only stops on the FNDC meeting Charge Parameters.
raysun
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Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by raysun »

Read at least p. 33 and study table that describes start and stop reason. I was wrong on my first answer, after a 2 min AGS it only stops on the FNDC meeting Charge Parameters.
I may be wrong, but IIRC, Voltage Start terminates when Absorb charging has completed. That will coincide with Charged Parameters Met in a properly programmed system incorporating an FNDC, but it doesn't have to.
fcwlp
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Posts: 1286
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My RE system: GS8048A, FM80 w/3,600W 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 install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by fcwlp »

raysun wrote: Thu Jan 25, 2024 8:06 am I may be wrong, but IIRC, Voltage Start terminates when Absorb charging has completed. That will coincide with Charged Parameters Met in a properly programmed system incorporating an FNDC, but it doesn't have to.
That is what I thought too, but not what the p.33 table states. On p.28 it states; "After a generator runs due to Voltage Start, it will be stopped when the inverter completes the battery charging cycle." So what is the definition of a "battery charging cycle? Inverter' parameters, FNDC's parameters or both? Who has the definitive answer? :grin:
.
With lithium it does not make much difference with the typical short absorb time, nearly matching the FNDC Charged Parameters met.
raysun
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Posts: 10865
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A-01 - Series Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
Off-Grid

Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by raysun »

fcwlp wrote: Thu Jan 25, 2024 8:49 am
raysun wrote: Thu Jan 25, 2024 8:06 am I may be wrong, but IIRC, Voltage Start terminates when Absorb charging has completed. That will coincide with Charged Parameters Met in a properly programmed system incorporating an FNDC, but it doesn't have to.
That is what I thought too, but not what the p.33 table states. On p.28 it states; "After a generator runs due to Voltage Start, it will be stopped when the inverter completes the battery charging cycle." So what is the definition of a "battery charging cycle? Inverter' parameters, FNDC's parameters or both? Who has the definitive answer? :grin:
.
With lithium it does not make much difference with the typical short absorb time, nearly matching the FNDC Charged Parameters met.
My (typically twisted) reasoning is Absorb complete, as a system can have AGS without an FNDC. The latter raises the CPM flag, which wouldn't occur if an FNDC isn't in the system.
(The above opinion asserted by one who doesn't use AGS. 😁)
fcwlp
Forum Emperor
Posts: 1286
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600W 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 install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by fcwlp »

raysun wrote: Thu Jan 25, 2024 9:31 am My (typically twisted) reasoning is Absorb complete, as a system can have AGS without an FNDC.
Agreed that seems to be the logical answer.
CFTX
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Joined: Fri Dec 08, 2023 6:20 am
My RE system: Outback FlexPower 8048
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Re: Batteries hit 50.8V for the first time and system used generator instead of the grid.

Post by CFTX »

So what is the consensus on why it stopped? The batteries certainly weren't charged in 15 minutes. Is it because of the flat voltage curve for Li-based batteries? In the future I wouldn't want the generator short-cycling if the power were off for an extended period of time.
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