Schneider Conext XW

[GXMnow]

When I did my power failure test, it had no problem doing bulk charge from the 5 working Enphase inverters. I was hoping all 16 would stay working, but 11 of the inverters glitched out on a grid frequency error. That being said... Running off grid for 30 minutes, it was pushing almost all of my AC coupled solar power directly into the batteries, but since I was only getting 600 watts from solar, it was way below my normal charge rate. I transitioned back to grid, and my charge current went back to 30 amps and went into absorb after just 15 minutes as the batteries were actually full at my set 57.6 volt limit.

What firmware version are you running? I had to upgrade my XW-Pro to 1.03 for it to work right and it added some features too. They also have a 1.04 now, but it looks like that just added the Hawaii grid codes. My Gateway is at v1.08

 

[Apex]

When I did my power failure test, it had no problem doing bulk charge from the 5 working Enphase inverters. I was hoping all 16 would stay working, but 11 of the inverters glitched out on a grid frequency error. That being said... Running off grid for 30 minutes, it was pushing almost all of my AC coupled solar power directly into the batteries, but since I was only getting 600 watts from solar, it was way below my normal charge rate. I transitioned back to grid, and my charge current went back to 30 amps and went into absorb after just 15 minutes as the batteries were actually full at my set 57.6 volt limit.

What firmware version are you running? I had to upgrade my XW-Pro to 1.03 for it to work right and it added some features too. They also have a 1.04 now, but it looks like that just added the Hawaii grid codes. My Gateway is at v1.08

Yea, I’m running the 1.03 for the Pro and 1.08 on the Gateway. I’m going to call them on Monday and see what they say, but I think they will not Know what’s going on.

 

[GXMnow]

You should definitely watch the XW status screen for a while as it starts limiting the power and raising frequency. It may shed some light on what event is causing it to limit. I know it is a remote site, but there may be something going out of range. Being completely off grid does make it an difficult balancing act, but it sounds like you should have plenty of battery to act as a buffer. Also check the logs and see if they shed any light on why it had to limit solar production.

 

[Apex]

Ok here’s the latest update on this issue with the XW pro and AC coupling. Had Schneider tech look at the settings and they had no comments there. They did tell me something I had never heard before. The XW will start curtailing at minus one volt from the desired voltage. So if you set 58 volts it will start at 57 volts. They said that the micros were pulling power back to aggressively and this was the issue with not getting to bulk voltage. So yesterday I tried a test and set float at 52volts and opened up the fstop/start window in the micros to 60.1 Hz start and 61.5 Hz zero output. Yesterday was a cool clear sunny day, battery voltage never got above 52. Today I will set the float to 58 and see what happens. I suspect this is not a compatibility issue, but a XW pro issue.

 

[r2d4]

@GXMnow do you have by any chance the .fw0 file for the XW Pro for firmware 1.03? I need to downgrade since I am having issues with the new firmware.

 

[RCinFLA]

Hello All, I have two XW Pro inverters AC coupled to 12 Chilicon micros and this system is off grid. We have installed AC coupling before with XW but not with Chilicon micros. I got the system up and running and what I’m seeing is the XWs raising frequency to curtail the micros prior to reaching anywhere near bulk voltage and in fact going up high enough to kick the micros off line. Here is the rub, if the micros are producing less then 2200 watts the XW will keep Hertz at 60, as soon as the watts goes above this it Shakes off the micros. Any ideas?

Two different things involved.

First on not fully charging, the XW is likely holding battery loading in reserve to allow it to manage a surge back if you switch off a significant AC load when PV production is high. Battery impedance goes up as they get near full charge, particularly bad for lead-acid batteries, so they won't be able to count on batteries to take a momentary back current surge when fully charged, for a long enough time for XW to detect surge back, move its frequency, which it cannot do too fast, and wait for GT to detect the freq shift and shut down.

Second on limited PV maximum power, GT inverters wiggle phasing to verify grid is present. An AC coupled hybrid inverter and its battery AH sizing must be strong enough to be able to resist this GT inverter grid testing. Worst mistake folks make is not putting large enough AH battery capacity thinking with all their PV power they don't need it. Same issue if inverter capability is not large enough compared to highest possible PV generation. Believe the manual gives recommendations but they are bare minimum.

Too much battery cable/path resistance can also impact maximum PV power support. The inverter cannot allow input terminal voltage to exceed its maximum limit.

 

[GXMnow]

@GXMnow do you have by any chance the .fw0 file for the XW Pro for firmware 1.03? I need to downgrade since I am having issues with the new firmware.

Yes, I am running Firmware 1.03.00 and I have the original ZIP file from when I downloaded it. PM me your e-mail address and I can send you the file.

 

[GXMnow]

Ok here’s the latest update on this issue with the XW pro and AC coupling. Had Schneider tech look at the settings and they had no comments there. They did tell me something I had never heard before. The XW will start curtailing at minus one volt from the desired voltage. So if you set 58 volts it will start at 57 volts. They said that the micros were pulling power back to aggressively and this was the issue with not getting to bulk voltage. So yesterday I tried a test and set float at 52volts and opened up the fstop/start window in the micros to 60.1 Hz start and 61.5 Hz zero output. Yesterday was a cool clear sunny day, battery voltage never got above 52. Today I will set the float to 58 and see what happens. I suspect this is not a compatibility issue, but a XW pro issue.

The XW-Pro does make a few assumptions that the Schneider engineers put in with very poor documentation about how they work. One new feature in the WX-Pro that the earlier versions did not support was being able to limit AC coupled charge rate. On the older units, it would only start to curtail when the battery was close to full. Starting the 1 volt below Bulk charge voltage limit. On the XW-Pro, it will also curtail if your charge current goes above what you have set in the "Maximum Charge Rate %" field. This is based on 140 amps as 100%. On my system, I have this set down to just 15% when I am on grid. This way it gently charges my battery bank at just 21 amps for the whole time there is sun hitting my solar panels. The rest of my solar power is feeding my home and some even goes back to the grid. But if I left it like that while off grid, it would try to curtail my solar down to keep my charge rate under 21 amps. So if I have a power failure, I need to bump this value back up to 80% to ensure my full solar production will be used to feed the house and charge the batteries. 80% is 112 amps which is still under 0.5C on my 360 amp hour Li NMC battery bank. Be sure this value is set safe for your battery bank. Lead acid should only hit about 0.1C which is why they recommend a minimum 450 AH battery bank. I want to do another grid power fail test here, but I am waiting on an answer from Enphase if they were able to find out why some of my inverters shut down on the 8ms changeover glitch. Last time, 4 of them went offline and reported "Grid Frequency Out Of Range" even though the other 12 all were working fine and my Fluke frequency counter showed the XW-Pro was dead on 60.00 Hz.

 

[GXMnow]

I see the Schneider firmware updates on their website, but they have moved on and are now listing version 1.09

Is this the version you are having problems with? I did send you the 1.03 I had.

It seems to have added a few features, updated some functions, and fixed a few bugs. I have downloaded it, but have not installed it yet. I will read over all of the changes before I commit to it. It also looks like the Gateway needs a different firmware for these to work together. Do you need to downgrade your gateway as well? I think I still have the Gateway 1.08 file also.

 

[Apex]

I haven't checked this forum in a while. My client who we installed the XWpro on is still having issues. I was able to document and show Schneider tech support that the XWPro in the off grid setup we have, with an AC coupled array is bringing the batteries up to absorb voltage but then immediately going into float despite having 180min. absorb time. Tech support said that engineering was able to verify this and agreed that this would need to be corrected in the next firmware revision. Also we are not seeing battery temperature through (insight) via the gateway, and they said that this was a known issue as well.

 

[GXMnow]

Mine is also not showing the battery temp. If I go to the XW-Pro status page, the temp there is accurate, but it is blank in insight. There is a version 1.09 update for both the XW-Pro and the Gateway, but it seems to have a lot of bugs. I will stick with 1.03 on the XW-Pro and 1.08 on the Gateway for now. It may not be perfect, but at least it seems to be stable and has been solid reliable for me for over 3 months now.

When my battery bank reaches the Boost Voltage of 57 volts, the current falls off very fast. At first I did not think I was getting any real absorption charge. When I did set it up to 58 volts, I would see about 15 minutes of absorb current, but at just 57 volts, it does not dip at all when the current falls from the 1,200 watt charge so it just stays there at 57 volts until my system flips to grid support mode and starts exporting 1,400 watts. The same thing happens on the bottom end as well. Once the inverter goes back from outputting 1,400 watts into standby mode at 9 PM, the Battery voltage is down to 50.6 volts, and only rebounds at most 0.03 volts. And after sitting 11.5 hours overnight, the battery voltage is still 50.6 volts. No further rebound or dip from there. I am quite surprised at how stiff this battery bank is. I was a bit concerned with having only 360 Amp Hours on tap, but the internal resistance is far lower than many other cells, so it takes these current levels like it's nothing. I will have to try running my AC compressor on it one of these days and see what happens when I do load it up over 5,000 watts. So far, I have not topped 3,600 watts. My normal On Grid mode is charging at just 1,200 watts and inverting at about 1,400 watts into my grid. My backup loads when I go off grid in a power failure will likely top out under 2,500 watts. Once I have my PLC controlling the XW-Pro, I hope to also have it monitor when the AC compressor kicks on, and it can crank up the inverter to push more power back to the on grid panel to ensure I stay below the high usage charges.

 

[Thorbjornw]

If I have understood the logic of the XW+ inverter series correctly, the basic assumption is that the systems have the battery bank as backup, but allowing for load-shaving in peak hours. If you want to use the XW+ inverters for recycling energy harvested during the day to the batteries (i.e. giving priority to the batteries over the grid), the only way is to disable grid support and use an external contactor. That is how our system is set up (working since August 2017). We have a separate system for backup (powered by 2x5 kWh LIFEPO batteries) of essential circuits (lights and communication) when the grid is down and we have no power left in hour main battery bank. The weakest point of the system in our experience is the external contactor. We had a 125A Schneider 4-pole contactor (very expensive), but after burning the contactor we wanted a bigger one (say 200 Amps), which we were not able to find. So what we finally did was to divide our loads in two with a 125A contactor on each. That works.
Th drawback is that we can't sell to the grid, so some energy gets wasted.

 

[GXMnow]

I have the XW-Pro version, which has a bit more procession power, but it seems to still have some of the same limitations.

If it was for backup power only, it would work perfectly. It tops up the batteries, and will not charge them again, unless the battery voltage falls to a set point. With my Li NMC battery bank, that could take months if I don't have a power failure. I have it set to export and load shave during th peak time of use here, which is from 4 pm to 9 pm. But the way their software works, it will stop running the inverter and go back to grid pass though when the battery voltage is still 0.5 volt above the recharge volts setting. So once it discharges down to there, it will just sit until their is a power failure, or just the parasitic loss brings the battery down another 0.5 volt to trigger a recharge cycle.

A few others and myself have been working on ways to get around this issue. One suggestion was to intentionally cause a grid fail to make it run off batteries and pull them down to the recharge voltage. I don't like the idea of having a contactor disconnect it from the grid. It looks like it will work, but it is a brut force way of doing things.

We are trying to send the Mod Bus command to trigger a charge cycle. It looks like 400bird may be close to making that work using a raspberry pi controller to send the commands. I am trying to use a small PLC controller.

Schneider's official fix is to have the system charged by using their MPPT solar charge controllers. The charge controller can be set to initiate a recharge cycle at a higher voltage, so each time the sun comes up, it just starts charging. The inverter stays in the grid support, load shave, and export mode all the time, and never has to go into charge mode at all. As much as it annoys me, I actually see the merits, and I am looking into adding 2,000+ watts of solar panel to a Schneider MPPT 60/150 charge controller. During the day, the existing AC coupled solar will directly power the house, and any extra exports to the grid and I get credit for it. At the same time, the DC coupled solar will charge up the battery bank. I will then also add the Watt-Node power monitor unit on my main grid breaker. It will adjust the export power from the XW-Pro to hold my consumption at zero. Any time I start to pull grid power, it will just ramp up inverter power to match. When my AC coupled solar is producing more that I use, it will ramp down the battery inverter until it is basically in standby. The AC solar will still export when it over produces.

 

[pvdude]

That is how mine works, when the sun hits the PV in the morning, the Schneider 100/600 MPPT charge controller charges the batteries.
I have charging turned off in the inverter.

 

[400bird]

What timing? I flipped the grid breaker off this morning and ran all day off grid (well until I left the house at 5:00 for dinner)

My 5-6kw of AC coupled solar and XW-pro did all day just fine. But the battery barely charged at all from about 50% soc up to about 60%

I'm leaning more towards doing something similar to GXMnow and adding some DC coupled solar (as a shade cover for part of the yard)

The 110° heat likely had something to do with that...

I really need to make some progress on the control program...

 

[GXMnow]

I came up with a nice compact cabinet for the new battery modules.

It does fit, a little tight, but room to get my hands in for wiring it. It's a basic Craftsman wall cabinet. It is rated for 200 pounds, and that is what the 2 blocks weigh. I have the terminals on the bottom, I am bracing the sides to support the batteries, and the braces will also have bolts go through the back to the wall, so the cabinet is not actually holding up any of the battery weight.

The shelf does still fit above the batteries. So I am going to put the BMS and fuses up on the shelf.

 

[keepsake]

Has anyone here come across data on the ModBus codes or protocols for xw6848 type inverters ? Or gateway ?
I see ModBus and tcp settings, can be enabled, at port 502.

I use that with SMA inverters, flawlessly. Now how to acquire the codes for Sch/Ele XW stuff.

If you ask me, when you buy this type of device, you should expect pdf documentation on all communication paths built-in to it.
Sick of being told that info is proprietary !! Horse s--t.

 

[400bird]

The modbus map is freely shared by Schneider and can supposedly be found on their website. I haven't seen it myself.

I'll try to remember to share the modbus maps this evening.

The modbus comm must be done through the Gateway/Insite. At least as far as I know.

 

[keepsake]

fyi -- I've found I can use a genset as a power source and with modbus controls, sync the inverter to supplement energy from pv, while house load is on generator. power_limit controls so as to leave genset with 25% of the house loads, pv up to 75%.

 

[400bird]

Lucky me, I got a few minutes at lunch time.

Turns out the forum only allows 10 files, so here's the first batch.