Schneider Electric SW 4024. Incorrect battery current displayed on system control panel

[esse elle gee]

I have a newly installed SW4024 with a Xanbus connected System Control Panel (SCP) and a MPPT60 CC.
-The system works well, except that when simultaneously charging and inverting, the SCP displays a battery current that randomly changes and is incorrect by up to 4 amps ( I verified with a meter that the system works well, it's only the SCP displayed battery current that is wrong).
- All 3 units have up-to-date f/w.
-The A/C load display jumps around as well, even though the actual A/C load is dead stable.
When I disable the inverter, the SCP displayed battery current is 100% correct (ie matches the charge controller).
-There are no logged faults or warnings.

Troubleshooting so far:
-triple checked wiring
-swapped out batteries
-swapped out inverter

Any ideas what could be wrong?

 

[acdoctor]

It looks like you have extra Xanbus cable tucked in with battery main feed. You are supposed to keep it as far away and shielded from D.C. . Almost comical isn’t it. You may be getting some interference.

 

[esse elle gee]

It looks like you have extra Xanbus cable tucked in with battery main feed. You are supposed to keep it as far away and shielded from D.C. . Almost comical isn’t it. You may be getting some interference.

Sharp eyes! Actually the cable tucked in with the battery is the extra length of battery temp sensor. Unfortunately, the issue happens regardless of whether the sensor is plugged in or not. The Cat 5 network cables are quite short, but I'll take your suggestion and play around with shielding it [Update: Shielding, new Cat 5 cable etc etc did not fix it]

 

[esse elle gee]

*****UPDATE****
Response from SE:

"Since [your setup has] no battery monitor/shunt, the SCP current reading is from the current transformer in the CSW inverter section. This does not have good resolution at low values and the feedback loop and charging of input or bridge capacitors could cause this bit of noise. It is fairly normal.

[with small loads like 40W] probably the resolution of the inverter's DC sensor is not able to read it. Please try increasing your loads more than 500-1000W to see if this 1A to 5A reading remains."

I confirmed that at higher loads (I tried 1000W), this condition goes away. Not ideal, but at least we know there's nothing unusual. I has suggested to SE that they note this condition on the manual as it was a bit of a wild goose chase for me.

 

[Solar Steve]

Agree - I have the same unit (SW4024) but monitor with the Insight Gateway rather than SCP. I have found the DC current measurements (and for that matter AC load measurements) to be wildly off at the low end. I simply use the Victron shunt (with Cerbo GX) to monitor power at this point and almost never look at the Schneider.

 

[OffGridICF]

The Schneider battery monitor is spendy, but it has better accuracy that is used by the rest of my Schneider system.

The Schneider Combox does not show any MPPT power less than about 100W, even when it shows some output current. You can see that in the included screen shot. The total current from the MPPT and battery should equal the XW current but there is an error. -6.5A - -4.8A = -1.7A but the MPPT output current is shown as 0.8 + 1.2 = 2A for a 0.3A error. I think the battery monitor and XW are more accurate and the MPPT current is wrong based on receiving a similar reply to yours from Schneider:

1. The combox's system performance will not be able to capture very low production, anything below 500W or even 300W will either be missing or not very accurate

My Chargery BMS shows a similar behavior for currents less than 0.5A which are shown as zero.