Mini Grid not switching to RE, but works with HBX enabled

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Mini Grid not switching to RE, but works with HBX enabled

Postby mikedowdell on Sun Oct 07, 2018 1:14 pm

I have a newer FXR inverter, Mate3s, FM80, etc setup as off grid but with Grid as backup to the RE system. My inverter is set to never charge the batteries so that RE will handle this for maximum grid savings. I cannot backfeed the grid. I initially had it setup as AC assist, but a few features weren't working as expected. I changed it over to Mini Grid with HBX and Load Grid Transfer enabled and everything was working perfectly as expected. While reading through the FAQ I stumbled on this article which says that when using Mini grid you cannot use HBX or Load Grid Transfer as they are incompatible:

https://opticsre.uservoice.com/knowledg ... o-with-hbx

However, it was working perfectly and honoring all my set points as I would expect. Following the articles recommendation, I disabled HBX and Load Grid Transfer but now my system never switches back to RE and instead stays connected to the grid all the time with the batteries at full capacity. I cant seem to find any settings , similar to HBX, as to what its criteria is to switch back to RE or Grid so I have no idea if its not reaching some threshold or ??? Any thoughts?

Since this was working ideally with Mini Grid and HBX enabled before, what are the reasons they are incompatible?
mikedowdell
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Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby Gwendoly Espe on Tue Oct 09, 2018 3:50 am

What is the end goal for you? You mentioned that some feature weren't operating as expected, what were you expecting?

A little bit ago a similar question was asked and here is my response below about HBX and Mini Grid. Basically they can override each other and create unexpected results.

The mini grid mode automatically connects to the grid based on battery voltage only. Grid load transfer function has the same connect to grid battery voltage, and has an additional setting that if the load is larger than a certain amount of kW that it would also connect.

In the manual it indicates:
Mini Grid mode is also incompatible with the system display Grid Use Time and Load Grid Transfer
functions. These functions do not have similar priorities to Mini Grid or HBX, but they do control the
inverter’s grid connection and disconnection. Mini Grid should not be used with these functions


This could be causing the disconnects as the priorities are different where mini grid mode wants to stay connected to the grid until a full charge and the other wants to connect after 50.8V. The Grid Load Transfer is prematurely disconnecting the inverters while the inverters are expecting a full charge (64V 12HRS) before disconnecting. I would suggest either changing the mode or disabling the Grid load transfer.
Gwendoly Espe
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Alpha Technologies Inc. / OutBack Power Technologies
3767 Alpha Way Bellingham WA 98226 USA
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Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Tue Oct 09, 2018 11:55 am

I have some constant loads, albeit small ones, which are contributing to excessive power rates due to usage. I cannot back feed to the grid! My overall baseline allotment is 320kwh a month. I am also on a time Of Use power plan where 4pm-9pm is considered peak and the most expensive. I have a pump which pulls 120v 1.85a (222wh) which over the course of a month consumes 160kwh, about half my baseline so my normal usage is pushing me into the second pricing tier. The pump is mission critical, it is responsible for keeping my 100 Tilapia alive for my Aquaponics greenhouse. An outage over 8hrs and the fish will start to become toxified and die.

So my priorities are:
1. Minimize overall Grid consumption
2. Eliminate grid usage between 4pm and 9pm daily
3. Provide a battery backup to help buffer any Grid outages when solar is not available (these usually last no more than a couple hours) (keeping the fish alive is my top priority, but i have a generator in emergencies)

Between 9am and 7pm I produce between 300-480 watts, PV delivers about 64v at 7amps to the FM80

Given the above I setup two different ways:

1. Grid Support: With HBX I was able to get everything working however when RE was no longer available, the grid would come back on right in the middle of my peak 4pm-9pm expensive usage peirod, i assume saving battery for backup in case there was an outage overnight

2. Mini Grid: With HBX I was able to satisfy all of the requirements and I seemed to be producing more power rather than grid over the course of the day. I would begin producting as early as 10am. The system would switch to consuming around 5pm and was able to stay there until after 9pm where it would return to the grid. But the documentation clearly states not to use HBX with Mini Grid.

3. Mini Grid: Without HBX, The system spends the entire day from 9am to 2pm charging the batteries (about 45ah based on the FM80, battery up to 29v), then it switches to RE where over the course of the next 3hrs the batteries drops back to 25v while PV maintains 300-450 watts. When PV finally cant sustain, it switches to consumption where it can only sustain for about 1h and then returns to grid right in the middle of my peak hours.

If the option 2 had not worked so well, I would assume my 2 12v 100ah AGM batteries were bad. So I'm trying to figure out what the setpoints are for the Mini Grid internally , since I have no visibility to them, to understand whats going on.
mikedowdell
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Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Tue Oct 09, 2018 12:59 pm

Configured against Mini Grid with HBX disabled....

On day 1, the system switched over after producing about 45ah to the batteries
minigrid-day1.jpg


The 2 new 12v 100ah AGM batteries configured in series to 24v should still have given me 50ah at 50 discharge but I only got 1.5hrs out of it

On day 2 (today), the system switched over after producing about 30ah to the batteries
minigrid-day2.jpg


I'm curious to see how many hours i get out of the batteries this afternoon considering it only charged to 30ah before switching over. I realize my PV sizing is smaller than optimal but the data is still not reflecting even close to expectations.
mikedowdell
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Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Tue Oct 09, 2018 7:51 pm

Today everything looked like it was working as expected, produced 85ah / 2.3kwh, however the batteries seemed to drop voltage fast and once again after 2hrs I'm back to the power company. I was expecting 4hrs. I'm wondering if the charging is shutting off early and that accounts for full pv and dropping voltage. Perhaps the inverter load is higher than I expected when its on.

minigrid-day2b.jpg
mikedowdell
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Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby Gwendoly Espe on Thu Oct 11, 2018 6:03 am

Hello,

Can you add your OpticsRE site name to your profile? This can expedite future help.


MiniGrid mode is intended for system designed to be more of an off grid system (off-grid sizing of Array and Batteries) with the Grid as a backup. If not, you'll be switching back and forth from grid to RE. And in order for the grid to disconnect, the batteries have to go through a full charging cycle. If you're charging from grid is OFF that could be until the next solar harvest.

All of this really depends on the size of the array and batteries vs the loads. If there isn't enough energy production/storage, then you either use the batteries for the peak times (if it can cover the entire time) and possibly not leave enough for backup or vice versa.

Here are Two Options:

Have you tried GridZero (it looks like you have 1 inverter, is that right)? It might be a good compromise. It will always pull 1A from the grid, but you can try the Grid Use Time function with it. Disconnect from the grid during the peak times. This will really test if you have enough RE capacity to do that.

Grid Use Time Note:If the battery voltage falls below the inverter’s Low Battery Cut-Out voltage, the inverter will automatically connect to the AC input source regardless of the time-of-day setting.


If you try this, you may want to increase the Low Battery Cut-out to have some capacity. Or you can try it one day and see what happens.


You can also try FlexTime. You can switch between multiple modes depending on the time of day. I'm not sure if this would work for your application, but for example, do GridZero mode during the off-peak times (use more Grid to support loads and leaves more capacity in the batteries) and then switch to Mini Grid mode during the peak times (this will use the batteries as if "off-grid", until the DC source is depleted according to Connect to Grid setpoint).

Change back to GridZero after the peak period.

With GridZero there is not battery charging from grid, so if you deplete the batteries in Mini Grid mode during the peak period, when you switch back to GridZero, the batteries will only charge from RE source. It all just depends on your system sizing. For example, maybe you wait until 3AM to go back to GridZero mode so that in MiniGrid mode you can charge the batteries up from the grid.


Have you considered those?
Gwendoly Espe
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Alpha Technologies Inc. / OutBack Power Technologies
3767 Alpha Way Bellingham WA 98226 USA
http://www.alpha.com
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Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Thu Oct 11, 2018 8:43 am

GridZero does not fit my needs at all more than likely due to the very small 1.8 amp load I am trying to eliminate to begin with. It doesn't make much sense to retain a 1 amp load to remove .8 of it. If my load was much higher, i believe this would be a more valuable and viable option.

I am currently running FlexTime settings, switching between Support in the day, and MiniGrid during my peak Time Of Use. I had considered this in the past but wanted to test other settings to try and troubleshoot.

Mini Grid by definition fits my needs well, it just doesn't seem to be working. That is not to say that its a problem with the Mini Grid settings, but without any visibility into, or tuning capability, its rather hard to troubleshoot why the batteries seem to be fully charging but are not able to sustain a charge. Looking at the power generation, volatages, and power consumption, everything looks ok... but my minimal is load drawing the batteries down way too fast. With HBX, I could lower the voltage cutoff numbers and the battery would level out and sustain longer but I feared I might be dipping too low into the depth of discharge.

I am beginning to suspect something is wrong with my 2 new batteries. After the batteries charged yesterday and power switched over to the inverter, my 100ah bank once again only last 2hrs on a 1.8a draw before it reached the minigrid cutoff of 25v. I turned on the Inverter charger last night and it bulk charged the batteries back to full in 11 min, and absorb charged in 50 min. This seemed ridiculously fast for batteries that were supposedly 50% drained. I ran a short equalization but the hour became late and i set it aside for the night, tuning off the inverter charger again. This morning I took some gravity readings from the batteries resting at a healthy 26.2v and they both seemed quite low for fully charged batteries at 1200. Something is not right.

For consistency, here is a view of the above testing:
minigrid-day3.jpg
mikedowdell
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Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Thu Oct 11, 2018 7:47 pm

I think we can close this discussion. I've charged my 2 new 100ah batteries against the inverter on grid and fm80 on PV, even run some equalization cycles and the results are the same... The gravity readings were dismal and suggest these batteries were likely sitting on a shelf a long time before I bought them (no month/day markings). So, I'm returning them. When I get my new batteries I will test and revisit if needed. Thanks for all your help.
mikedowdell
Forum Whiz
 
Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby omarbur on Thu Oct 11, 2018 9:03 pm

Hello mikedowdell;
I have the same situation, The point that Charge controller need to be a litter be higher (.4V) , below the example in my system (24V):

FM80

Absorb Voltage................29.6VDC
Float Voltage....................27VDC
Absorb Time.....................2.5Hrs

VFXR3524A

Absorb Voltage................29.2VDC
Float Voltage....................26.8VDC
Absorb Time.....................1Hr
Float Time.........................1Hr

BR
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Kyocera:
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Midnite:
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Outback:
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Tools:
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Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Fri Oct 12, 2018 8:34 am

My inverter charge controller is disabled, I only charge from PV unless manually intervening for test sake. However, this is good info to check for testing.
mikedowdell
Forum Whiz
 
Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby Mike Curran on Fri Oct 12, 2018 2:54 pm

I'm curious, how are you measuring specific gravity with AGM batteries?
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
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Westinghouse Solar:
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Re: Mini Grid not switching to RE, but works with HBX enable

Postby mikedowdell on Fri Oct 12, 2018 3:24 pm

Old info, on flooded lead set now.
mikedowdell
Forum Whiz
 
Posts: 33
Joined: Wed Sep 12, 2018 10:04 am
Location: San Diego, CA
My RE system: Outback FXR2524A-01, FlexMax FM80, Mate3s, Power Hub 4
6x Solar World 250w panels on a 2 axis solar tracker
2x 12v 100ah Flooded deep cells
Hybrid Off Grid with AC as backup

Re: Mini Grid not switching to RE, but works with HBX enable

Postby Gwendoly Espe on Thu Nov 01, 2018 3:16 am

There will be a webinar coming that talks about these modes!

Radian and FXR AC Input Modes / Operating Modes

Date: Wednesday November 14, 2018
Time: 10:00AM - 11:00AM PST

Registration:Click Here to Register!


Class Description:
OutBack’s grid connected inverters have a unique collection of operating modes designed to optimize utility power usage for the OutBack customer. These different operating modes offered in the Radian and FXR series inverters are how the system interacts with the grid or AC source; each mode has different rules on how or when they connect to the grid. These modes include: Grid Tie, GridZero, Mini Grid, Support, Backup and more. We'll touch on HBX, Grid Uese and FlexTime. This webinar is for installers or end users who are comfortable with OutBack Products, the profile wizard and want to learn more about programming.
Gwendoly Espe
Applications Engineer


Alpha Technologies Inc. / OutBack Power Technologies
3767 Alpha Way Bellingham WA 98226 USA
http://www.alpha.com
User avatar
Gwendoly Espe
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Posts: 123
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