Overvoltage with Schneider XWPro 6848, Context

[FullMoonSolar]

Hello,

I am new to this forum so this question may have been discussed in the past without me being able to find it. If so, I apologize.
I have several systems but one off-grid system has Schneider XW Pro 6948, Context MPPT 100 600, with a Kilovault 48 volt battery set.
I received an Overvoltage alarm from the Schneider insight system for the first time in the 14 months Of operation. I immediately checked the Kilovault system and then drove to the site to check the actual voltage with a meter. The battery never exceeded 56V as designed As far as I can tell. There is no grid or generator system installed.… only the CC. I suspect an erroneous alarm from the Schneider. I
I can’t find any comments in the Schneider documentation regarding the cause for this alarm. Given their customer support reputation, I am not expecting a response for a while. Does anyone have any thoughts about what to check or watch for?
Thank you in advance.

 

[acdoctor]

My best guess is the BMS in the kilovault disconnected towards the end of charge due to a high cell voltage. By the time you arrived it had rest. I would keep an eye on the battery. Does it have a way to monitor individual cells?

 

[MichaelK]

I have operated my XW+ for years now, and have never once seen that warning. I have seen low voltage warnings when I've run my well-pump too long after dark. I would agree with ACD that it is somehow BMS related. I have lead-acid, which appears far more forgiving.

 

[FullMoonSolar]

Thanks for the replies.
According to the Tech Support, there is no way to monitor individual cells - it’s a sealed unit LiFePO. The battery monitoring system in control is a Schneider Conext BMS/Insight and it controls the CC. The 7.5kw battery monitoring is for display only though I get info on-line from both systems. There is no closed loop control between the two companies.
Based on the on-line trends from both systems, I don’t suspect the battery ever really went above the max voltage. There is not enough idle consumption to bring the system from 68v to 56v within the 20 min it took me to arrive and measure. it only uses 250w continuous unless the shop is running. At that time however, all 3 sets of data were in agreement at 100%.

 

[acdoctor]

If BMS disconnect due to one cell the Schneider system would loose reference voltage from batteries causing the high voltage. In the 20 minutes the one cell dropped below cut off limit and reconnected battery allowed system to recover to proper voltage. You can test this by disconnecting the battery while charging or just wait if it happened once it will happen again the next time you have a high amperage charge day.

 

[FullMoonSolar]

If BMS disconnect due to one cell the Schneider system would loose reference voltage from batteries causing the high voltage. In the 20 minutes the one cell dropped below cut off limit and reconnected battery allowed system to recover to proper voltage. You can test this by disconnecting the battery while charging or just wait if it happened once it will happen again the next time you have a high amperage charge day.

That sounds like a potential cause. Thanks. I will continue to monitor.
thanks for the guidance.

 

[dobrzpe]

i wouldn't think one cell in the battery going 'over voltage' would set off the XWpro's high voltage alarm. it may (should) cut the battery off, yes, but not set off the inverters alarm. so:

1) what is the over voltage alarm set to in the XWpro6848?
2) what is the bulk/absorb set to in the 100/600?

maybe something got reset somehow.

you mentioned you have the battery monitor. you can check in Insight Cloud what and when the historical voltage was. (that sounds confusing, i'm talking about looking at the logged voltage data, specifically for the time the alarm occurred.)

and, yea, good luck with schneider customer support! (from experience)

 

[400bird]

I've seen that over voltage alarm multiple times.

It doesn't set at 68 volts. It's based on your over voltage disconnect or some similarly named setting. Plus, this is the warning type alarm, so it sets at some point below your setting in the XW. I'm going from memory, but 3 volts comes to mind. I'd have to dig up the info from another thread of mine.

If the BMS did disconnect, the charge controller would likely continue outputting energy and continue to raise bus voltage to the absorbtion or over voltage cut off.

Edit: I didn't realize this was an old thread, hope you got it sorted!