Page 3 of 4

Re: AC coupled - batteries not charging from solar array during outage

Posted: Wed Nov 27, 2019 10:04 am
by Greg T Fordan
So you got it! That is the only screen you have to deal with regards to AC coupling. Do not even touch the Grid Interface Protection menu.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Wed Nov 27, 2019 1:24 pm
by Swampdog
OK. No worries... I never change any setting without clear guidance.... hence my myriad posts and emails. Doesn't help my struggle to have inconsistencies between documentation and display menus.

Question remains: Do I change the Frequency Shift Response Time (Battery Sample Time) to 3 seconds, or not (currently .02 s).

References:
1) acc_freq_app_note.pdf: This document states: "Change AC Coupling from N to Y, and change the Freq Shift Response Time (0.02 to 5.0 seconds) if desired. This setting adds/subtracts delay in the frequency steps between 60.0 and 64.5 Hz."

2) Ian McClusky stated in an email communication: "We recommend the minimum (0.02 seconds) Frequency Shift Response Time for lithium ion batteries only, and about 3 seconds for most lead-acid batteries." (I have 220GH batteries)

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Wed Nov 27, 2019 1:40 pm
by Greg T Fordan
I recommend staying with .02s since it is obviously working at this time, when you are AC coupled with the grid and the Radian.
Now, when the next grid outage comes around, and you encounter the issue of the SolarEdge inverter not syncing with the Radian, maybe that is the time to tinker the setting from the default .02s.


But here's the Here and Now -->Your system is doing good, selling a daily average of 15 kWh + to the grid. The "Buy" times are very few and far between. If I own that system, I will be quite satisfied and not worry about tweaking other settings, for now :-"


Apologies for the literature that were not updated. Yes, from the old way of doing AC Couple, the menu was inside the MATE3/MATE3s menus.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Wed Nov 27, 2019 2:21 pm
by Swampdog
OK. Yes... system is doing better than ever since I resolved my water system leak (under concrete driveway). If you didn't read that... it was short-cycling my well pump, obviously using a lot of power, for what could have been years... likely started as a dribble and then increased to a gusher over time. No above-ground evidence of leakage.

I don't anticipate any S/E or battery issues not that the well pump issue has been resolved, but if that occurs... I will recognize it and have a much better understanding of why and how to resolve.

So... the as yet unanswered, hanging questions...
1) FLEXnet DC Advanced Control-Enable Auto Grid-Tie Control... Yes or No. I would prefer charging to be the priority over selling. If Yes... will not my issue with FNDC Days ChargeParmsMet affect that?

2) OpticsRE-FNDC-Days Since Parms Met = 34 days. How can I correct this?

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Thu Dec 26, 2019 6:11 am
by clarkef
Swampdog,

Did you get your question answered? It’s a month later - have your batteries met charge parms yet?

I’ve found that that my charge parms met doesn’t always reset “days since..” unless the batteries sit at their float setting (and presumably the float timer expires). This came up for me in the last two days - for the first time in 10 days I hit my 100% SOC and immediate added a bunch of load to take advantage of a full charge. The “days since” did not trip over. Yesterday I hit full charge and did not add load and the “days since...” did trip over.

P.s. if you. Still have the ROCB that was removed from your system when you went AC coupled with the new firmware, I’d be interested in buying it from you. I need one for another project and haven’t been able to source one cheaply.

Clarke

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Dec 29, 2019 11:34 am
by Swampdog
Although maintaining 99-100% SOC, Charge parms met as reported by FNDC cites over 60 days.

I do not have the removed ROBC.

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Dec 29, 2019 4:58 pm
by Mike Curran
This FNDC application note http://outbackpower.com/downloads/docum ... p_note.pdf describes the settings for charge parameters met as follows:
Screenshot_20191229-193938_Adobe Acrobat.jpg
The 3 important parameters for meeting charge parameters are charged voltage, charged return amps and charge time. The app note explains how a combo of these 3 set point determines if charge parameters are met. If your system isn't meeting all 3, it won't meet charge parameters.

My 2007 system routinely meets charge parameters when there's sufficient sun. Here's a screenshot from 12/27:
Screenshot_20191229-195219_Samsung Internet.jpg
Here's a screenshot of my charge parameters:
Screenshot_20191229-195531_Samsung Internet.jpg
Hope this helps.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Mon Dec 30, 2019 3:44 pm
by Swampdog
Mike, et al;

Attached are my settings and today's data. Sun is a bit low this time of year, but weather was pretty clear. As my Grid-tie inverter is SolarEdge, I included today's SolarEdge panel array production.

I read that the FNDC Charge Voltage should be lower than the GS8048A Absorb Voltage. Both those settings are 57.6VDC (default for both). Could that be my issue with Parms Met (now 67 days)?
FNDC & data 12-30-19.pdf
(147.26 KiB) Downloaded 170 times
S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Mon Dec 30, 2019 3:57 pm
by Mike Curran
I read that the FNDC Charge Voltage should be lower than the GS8048A Absorb Voltage. Both those settings are 57.6VDC (default for both). Could that be my issue with Parms Met (now 67 days)?
Absolutely! Here's the relevant info from the app note:

"Since the charging source (inverters and charge controllers) will drive the battery voltage up to its Absorb set point, the Charged Voltage should be programed below (0.4V for 48V, 0.2V for 24V and 0.2V for 12V systems) the Absorb Voltage set point of the charging source. For example, if the inverter’s Absorb Voltage is set to 58.4V, then the Charged Voltage in the FN-DC should be set to 58.0V. This will guarantee that the Charged Voltage value in the FN-DC will always be met as the charging source will drive the battery voltage up to its Absorb set point."

So your charged voltage should be set for 57.6 - 0.4 = 57.2. If you want to attain a higher absorb point, adjust both settings up but make sure the charged voltage in the FNDC is set 0.4 volts lower than your inverter absorb setpoint.

I think if you do this you'll see charge parameters met.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Mon Dec 30, 2019 4:50 pm
by Swampdog
Mike, et al;

Done.

So wondering what changed, I looked back in my record to 67 days ago, the last time the Charge Parms were met.

I had experienced a serious battery power consumption problem during an outage, hence this thread (and some others). I eventualy figured out our well pump was constantly short-cycling due to a major leak under our driveway slab. Once repaired, all perceived solar issues resolved. However, I wallowed in solar tech support for several weeks, not realizing the cause. Some other settings issues did come to light, however.

I was directed to change the following, which I did, exactly 67 days ago:
Radian GS8048A: Changed Absorb charge settings from 1 hr. to 4 hrs.
FNDC: Battery AH from 400 to 660 & Charged Voltage from 28.7 to 57.6.

Charge Parms not met ever since.

We will see tomorrow, when the sun comes up methinks!

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Thu Jan 02, 2020 11:06 am
by IanMcCluskey
Hi S/D, I looked at the last few days of history, and though the system seems to perform as expected, I see the FN-DC still reports 70 days since parms met. I will try to find out why. I would not worry about it affecting performance at this point.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Thu Jan 02, 2020 11:34 am
by Greg T Fordan
SD, remember that your FNDC "Charged Voltage " setting used to be 28.8VDC and a wrong setting. That was the reason you were frequently getting a "Charged Parms Met" because it was easily getting its target of 28.8 VDC which did not apply/meaningless in your 48V system in the first place.
If you really want to get some of that "Charged Parms Met" reports again, try this: Lower your "Charged Voltage" setting to 51VDC.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Thu Jan 16, 2020 5:17 pm
by Swampdog
Group;

OK, so I think I am getting the idea about the role of the FNDC. I adjusted the Charged voltage a couple times and was able to get the Days Since ChargeParms Met to reset. Currently watching array output versus Charged Voltage settings to decide what to leave it at. Interestingly, when attempting to change the Charged voltage through the FNDC device via OpticsRE, it will not accept the setting of 51v you recommended (Greg). Does allow 52v.

New issue: I have the following settings in place.
Settings > MATE3s > FLEXnet DC Advanced Control:
o Enable Charge Termination Control: Y
o Enable Auto Grid-Tie Control: Y
o Offset Enable: Y

Although the MATE3s Programming Guide claims setting Enable Grid-Tie Control to "Y" causes Offset Enable to automatically revert to "Y". 1) That did not occur, so I set it manually. 2) After re-checking numerous times, Offset Enable always reverts to "N". I have manually reset to "Y" numerous times, to no avail.

What could be causing this and how might I remedy it?

My goal is to fully charge the batteries from the array before selling... which does not seem to be occurring as it should.

Thanks for any input!

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Thu Jan 16, 2020 6:05 pm
by Mike Curran
I would try disabling auto charge termination control. That's how my system is set up and it works properly.
Screenshot_20200116-210403_Samsung Internet.jpg

Re: AC coupled - batteries not charging from solar array during outage

Posted: Thu Jan 16, 2020 7:21 pm
by Swampdog
Thx... but I have no FLEXmax charge controllers, which I believe the Global Charge menu is intended for. Global Charger Control id "Disabled".

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Fri Jan 17, 2020 6:58 am
by Mike Curran
Based on the Mate3s manual, I think the global charge menu applies whether you have an fm80 or not:
Screenshot_20200117-100547_Adobe Acrobat.jpg
I would still try disabling auto charge termination, just to see if it makes a difference.

Re: AC coupled - batteries not charging from solar array during outage

Posted: Fri Jan 17, 2020 8:29 am
by Swampdog
OK... done. I see the MATE3s Programming Guide states that an FNDC is required (only). We will see. Wondering then, as Global Charger Control is set to the default "Disabled". Should this be enabled?

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Fri Jan 17, 2020 10:04 am
by Mike Curran
Swampdog wrote:
Fri Jan 17, 2020 8:29 am
OK... done. I see the MATE3s Programming Guide states that an FNDC is required (only). We will see. Wondering then, as Global Charger Control is set to the default "Disabled". Should this be enabled?
Based on the manual, sounds like global charge control is just to limit total battery charging amps from FM's plus inverters, but it doesn't limit charging from inverters so I'd say with your system it doesn't matter. Disabled should still allow the other settings to work. Here's what the manual says about it:
Screenshot_20200117-130341_Adobe Acrobat.jpg

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Jan 19, 2020 5:37 pm
by Swampdog
OK... tried that, but Offset Enable still reverted to "N". No idea when exactly that occurs. The Programming Guide states that if Auto Grid-Tie Control is enabled (Y), Offset Enable will automatically switch to enable (Y). That has never occurred. Have reset many times to "Y"... to no avail.

Here are some relevant settings:
• Settings>MATE3s>Global Charge:
o Auto Charge Terrmination Control: Disabled (as recommended by Mike Curran)
• Settings>MATE3s>FLEXnet DC Advanced Control:
o Enable Charge Termination Control: N
o Enable Auto Grid-Tie Control: Y
• Settings>Inverter>Grid-Tie Sell: Offset Enable: Y (eventually reverts to N, consistently)
• Settings>Inverter>AC Coupling:
o Inverter-AC Coupling-AC Coupling Enabled: Y

So my questions are... why does this occur and does it matter? If it matters... how can I correct it?

Thx!

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Jan 19, 2020 7:12 pm
by Mike Curran
Settings>Inverter>Grid-Tie Sell: Offset Enable: Y (eventually reverts to N, consistently)
Mine also reverts to N, until charge parameters are met, and then it changes to Y. Until midnight when it resets to N again, waiting for charge parameters to be met again. During cloudy periods, this won't happen until the sun comes out - possibly for days.

I'm just a beginner when it comes to AC coupled arrays, so I don't know if you can expect your AC coupled array to charge the battery unless the grid goes down... if that's your only PV charging source, you may never meet charge parameters. However, I'm re-reading your post and I see your system isn't charging when the grid is down - is that still the case?

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Jan 19, 2020 7:34 pm
by Swampdog
No. The real source of my issues was a water leak causing a well pump to cycle every few minutes. During an outage, batteries low voltage shutdown, triggering other issues. Leak is fixed and I understand what occurred.

What you describe with Offset Enable and your system may well whst happens... I have read nothing on this in the literature.

Batteries can charge from array, grid, or both depending on load.

If your description of on and off Offset Enable is correct, then all is working as it should as well as selling a lot of power.

Thx for your help.

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Mon Jan 20, 2020 10:04 am
by IanMcCluskey
Thread moved to the newly created AC Coupling forum

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sat Feb 08, 2020 12:24 pm
by atomicsolar
ROCB is tripping main breakers? Would AFCI trip it as well? Could be a load in the back up panel, like a pump pressure switch arcing, setting off the AFCI?

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Feb 09, 2020 3:15 pm
by Swampdog
I thought all was resolved, but we are now in the midst of the first outage (high winds bringing down lines) since my previous issues. Today we suffered a power outage and I noticed the batteries seemed not to be charging from the array, although we have a cloudless, sunny day. Upon checking my SolarEdge 6000 inverter, I saw the original fault returned. This time, there is no low voltage issue.

In 4.5 hours batteries have dropped to 90% and <50vdc. I am thinking I need to connect the generator and charge up before I run into the low-voltage shutdown again.

No idea where to go with this, this time around, since I thought all settings were appropriate and my power drain resolved (cycling well pump). Any assistance appreciated!

S/D

Re: AC coupled - batteries not charging from solar array during outage

Posted: Sun Feb 09, 2020 3:38 pm
by Swampdog
Update:

Before connecting the generator, I was able to clear the SolarEdge fault and it appears, at the moment anyway, array is charging batteries and voltage rising. Not enough daylight left to fully charge, I am sure, sop may supplement with the generator a bit later.

This leaves me to believe there was a problem switching immediately as the grid power failed, so likaly a setting.

Assistance still needed to analyze this, however.

S/D