Adding Schneider XW Pro

[400bird]

24V? I read 12V on one transmitter data sheet

I guess I should have done the research not just posted my thoughts. Just a lazy evening
I was thinking it has a 12-24 VDC input range.

You're right, the spec sheet only calls out 12v

Oddly enough, I have basically the same panel sitting here in the office. It's designed as a car battery maintainer.
I doubt that 7"*8" panel will do 22 watts, mine is close to 14" square.

It still seems easier to just a Milwaukee M12 battery.

 

[Hedges]

Reality check!

7" x 8" - maybe it's 55% efficient. Yours are only 16%!


Now how do you black start the Milwaukee battery? Got an AC charger for it?

 

[400bird]

Between the 6 of those M12 batteries (and 3 car batteries) I'll be fine.
I'm not a prepper, and even if I was, I think I'm covered. I have never heard the saying past "two is one" Then what's 9?

Crap, 10
The truck has two batteries.

 

[GXMnow]

If you want to make it totally automatic, you could add a relay to switch the RSD to a DC to DC converter off of the battery system when the grid fails.

 

[400bird]

If you want to make it totally automatic, you could add a relay to switch the RSD to a DC to DC converter off of the battery system when the grid fails.

I thought about this, but there's two issues:

1. The supply to the RSD transmitter (through the knife switch and AC/DC) is already on the output of the XW, so this highly improbable issue would only present when the grid is down and the house battery dead.
2. If I wired it to a relay, with the grid on N.O. side and 12v battery on the N.C. side, what would happen when a firefighter pulls the AC cut out? Seems like it would defeat the purpose of having the RSD entirely of it fails over to a different power source automatically.

 

[GXMnow]

That is an interesting situation.

Maybe add a micro switch that is pressed when the knife switch it flipped to open the 12 volt DC to the RSD transmitter??

I have not done it yet, but I am thinking about making the knife switch for my Enphase system also command the XW-Pro to shut down. So just one switch will also cut the power in the house. My DC system is still acting as if it is just off grid on a non living space. I will add RSD at some point, but I am just barely over the voltage. Under load they only run 85 volts. One relay that splits the array in half would meet the under 80 volt requirement.

 

[400bird]

That is an interesting situation.

Maybe add a micro switch that is pressed when the knife switch it flipped to open the 12 volt DC to the RSD transmitter??

I could do that now that the inspection is complete, there's no way it would have passed inspection that way.

I have not done it yet, but I am thinking about making the knife switch for my Enphase system also command the XW-Pro to shut down. So just one switch will also cut the power in the house.

I'm not sure that is required, at least it wasn't under the previous codes when I installed the XW.

My DC system is still acting as if it is just off grid on a non living space. I will add RSD at some point, but I am just barely over the voltage. Under load they only run 85 volts. One relay that splits the array in half would meet the under 80 volt requirement.

Hmm, good point. Too bad VOC is what counts, mine dipped down to about 75 volts today.

 

[GXMnow]

My XW-Pro is having an interesting issue.
It is failing to stop charging. It is more than 0.3 volts above the absorb voltage settings, and still in bulk mode.
I even went into the charger settings and lowered "Bulk/Boost Voltage Set Point" "Absorption Voltage Set Point" and "Float Voltage Set Point" all to 56.6 volts and it still stayed in Bulk mode charging at 26 amps with the voltage showing 57 volts.

Have you ever seen this happen?

I was concerned it might be the PLC sending bulk commands, so I even unplugged that and it still won't stop charging unless I hit "No Float".

 

[400bird]

I haven't, it always has followed the bulk/absorb voltage settings. But, I haven't been anywhere near 100% since about November.

Sun was out in full force today, for the first time in a while, but the car took some of the solar. House battery made it up to about 78%

I'd probably write small changes into all the charge voltage settings to see if that helps.

 

[400bird]

Edit, any chance the Victon charge controller was still going and the increased voltage level was causing an issue for the XW?

 

[GXMnow]

Edit, any chance the Victon charge controller was still going and the increased voltage level was causing an issue for the XW?

I am also thinking that it might have something to do with the Victron charge controller. This issue has only happened since that was added. But the BougeRV controller also did keep pushing the voltage higher without an issue. The XW would do a very short absorb cycle and as soon as the voltage went above 56.7 volts, then no more current from the XW at all. Is the Victron CC putting out current/voltage spikes that might be confusing the voltage reading in the XW?? I could possibly se that, but the voltage readings in the XW on Insight Local all show the voltage climbing 0.3 volts above the set point and it was still cranking out nearly 30 amps. The Victron was also pushing 20 amps at the same time.

I got a field job today, so I won't be here to monitor it today, but the weather forecast is calling for "partly cloudy" all day. Battery voltage at 6 am is down to 52.5 volts, (still a bit over 50%) it will drop a bit more before any sun comes out. The system would need to produce over 15 KWHs beyond the house draw to top it out. I'll check the graphs when I get home.

 

[400bird]

I am also thinking that it might have something to do with the Victron charge controller. This issue has only happened since that was added. But the BougeRV controller also did keep pushing the voltage higher without an issue. The XW would do a very short absorb cycle and as soon as the voltage went above 56.7 volts, then no more current from the XW at all. Is the Victron CC putting out current/voltage spikes that might be confusing the voltage reading in the XW?? I could possibly se that, but the voltage readings in the XW on Insight Local all show the voltage climbing 0.3 volts above the set point and it was still cranking out nearly 30 amps. The Victron was also pushing 20 amps at the same time.

My system acts the same (not thr ignoring the charge voltage set points, but the rest of your description)

I got a field job today, so I won't be here to monitor it today, but the weather forecast is calling for "partly cloudy" all day. Battery voltage at 6 am is down to 52.5 volts, (still a bit over 50%) it will drop a bit more before any sun comes out. The system would need to produce over 15 KWHs beyond the house draw to top it out. I'll check the graphs when I get home.

Fingers crossed, how'd I behave? I didn't get enough sun here to come close to showing what mine does. My peak SOC this afternoon was 51%

 

[400bird]

Well, if I wasn't already sure, I'm now convinced, this is an addiction. I don't need it, but I picked up 48 used EVE cells from Ampster. Huge thanks, they were a great deal!

Anyways, was going to put them together into 3 parallel 16s packs.

However, I can't lift a 16s pack, so I was going to clamp them in 8s strings with 2 in series on a single BMS to make each 16s battery.

Then, I picked up my enclosure and discovered I couldn't fit them in place at 2 8s strings. So that's each 16s battery will be clamped as a 2 groups of 5 and one group of 6 (modules of 5 or 6). Still on a single BMS.

That means I'll have 9 clamped together modules and 3 BMSs. Likely Batrium, I prefer the external shunt and I already purchased a shunt trip breaker.

Anyways, I did a test assembly on the first module of 5. I'm glad pulled back to 5&6! This is much easier to move around than a module of 8 would have been.

The end plates are 3/16" steel, the clamp rods are 1/4"-20, there's 1/4" plastic insulation on the bottom and sides. Then a thin sheet of HDPE between the cells.
Yes, I messed up for this test fit and put the last cell on backwards, good thing I'm not doing bus bars on this test fit.

The plastic sheets between the cells is fiddly and was annoying to get in right. I think I'll pick up some katpon tape to both cover the tears in the blue shrink wrap and attach the HDPE insulation sheets.

 

[GXMnow]

Are you going to swap from the NMC cells to LFP? I could not find a voltage range to make them work well together.

 

[400bird]

Seems like I can limit the voltage on each and parallel 14s NMC and 16s LFP

Until you mean mentioned it, I forgot I had this thread discussing exactly that:

Paralleling LifePO4 banks with...

Thanks to a gracious member here, I just picked up 48 LifePO4 cells that I plan to build into three 16s batteries. I had I initially considered retiring my current battery bank (14s NMC) But, now I'm reconsidering... Please, let's stay on track. Can we please not discuss everyone's fear in...

diysolarforum.com

 

[GXMnow]

I looked at the other thread.

A while back I did the same math and figured it would not fail in a bad way, but the batteries from the 2 banks will not share the current.

It was noted in the other thread, so I will just keep my comment short here. During discharge, the NMC cells will provide the bulk of the current while the voltage is above about 54 volts. Then when the voltage goes below 53.5 volts, the LFP cells will take over and handle most of the current. The NMC cells will provide very little of the current until the voltage goes into the lower knee of the LFP cells ate about 51 volts.

The situation during charge will be very similar. While the LFP cells are in their flat plateau, they will be handling most of the current. Above or below that range, the NMC cells take over.

It could make for an interesting experiment to watch the current over time from both batteries as the system discharges. I tried a small experiment with my 2 E-Bike batteries. They are essentially identical, but I can run them separate, or in a parallel pair for more run time. One was only at 75% SoC while the other was close to 90%. When I connected them, there was about 6 amps flowing from the higher charged pack. But as I pulled a load from it, the lower pack just stopped being charged. Under a heavy load, the higher state pack voltage was pulled down close to the lower state pack.

 

[400bird]

Yeah, the load/charge current will pass back and forth between the two. I don't think I need to be concerned about that; either system should be able to support the full load.

My concern would be how LPF wants to have the cell voltage relax down after a full charge. As you know, the NMC pack doesn't do that.

 

[400bird]

And I just realized how glad I am that I assembled this test pack. Odd numbers of series cells have the positive and on opposite sides. Had I drawn or modeled this out more fully I would have seen it

Ok, new plan each 16s string will be two 6s modules and one 4s module all in series.

That will make the connections easier and these are going on a shallow cabinet, where the only layout that makes sense is to have each 16s lined up straight left to right with the back face nearly touching the enclosure wall.

 

[400bird]

On a different subject, I had another one of these events, where the XW charges and discharges from the grid on a wild back and forth full blast in both directions. At 9:30, while I was in the garage to realize what was happening.
I tried a few different things before I realized I should measure the frequency, 59.97 Hz on one meter and 59.99 on the other.
Look what the grid codes calls for, response at 59.96 hz. That seems like it could be just a measurement error away from what I measured.


So, I added 2 second delays to both activation and deactivation along with spreading out the center dead band around 60 Hz to 59.9-60.1

 

[GXMnow]

I think you are onto something here.

It sure would be nice if the system would log when these actions happen. Then we would know which one caused it.

The other thing on this page "Freq-Watt P(f) Droop" that is a bit scary to me is the "Ramp Rate Increment" at 33% per second. I slowed that to just 10% per second.

On the two "Freq-Watt P(f)" entries, I also moved the threshold out to 59.9 and 60.1 Hz. I want it to just ride through between those limits.

I am also looking at the voltage and power reactions. Most of them have the ramps set slow, to just 1% per second. I changed the others that were at 33% down to 10%.

The other one that looks funky is "Ramp Rate"
The "Normal Power Ramp Rate" is at 100% per second.

I will leave that for now and see if it does the wild power swinging again with the other changes. If it does, I may slow these rates as well.

The "Power Settings" page seems to be disabled. So I don't think those settings will do anything. But since my breaker back to the main panel is only 20 amps, should I lower those power limits?? All three are set to 6,800 watts or over 28 amps at 240 volts.