Deye 12kw inverter error: F21 Tz HV OverCurr Fault

[InverterSpace]

Hello,

I am reaching out for assistance with an error code "F21 Tz_HV_OverCurr_Fault" I'm encountering on my Deye 12kw inverter.
Here are the details of my setup:

Inverter Model: SUN-12K-SG04LP3-EU
Lithium Batteries: 2 Narada 48NPFC100
Solar Panels:
* 525 watts - 14 panels
* 405 watts - 16 panels (8X8 panels connected 2 strings for 1 MPP tracker)

Additional Details:
All AC and heavy loads are connected with a smart load on each phase, except for one AC unit, and most of the time I encounter that issue in the morning or during peak load

I would greatly appreciate any insights, suggestions, or troubleshooting steps you can provide to help me resolve this error code.

I have attached screenshots of the configuration for reference in the thread. Please take a look.

 

[XO4001]

* 525 watts - 14 panels

Is this 1 string?

 

[InverterSpace]

Is this 1 string?

2nd string

 

[XO4001]

Are the 14 panels in 1 string?

 

[InverterSpace]

Are the 14 panels in 1 string?

yes 14 panels in one string and 8x8 in 2nd string

 

[houseofancients]

did you already request a firmware update ?

 

[XO4001]

If they are 1 string then that is were your problem is 14 X 49V= 686V

Edit,
I think the max voltage is 500V but read the manual to be sure.

 

[InverterSpace]

PV1 405 watts - 16 panels (8X8)
PV2 525 watts - 14 panels

 

[InverterSpace]

I didn't update the inverter firmware but I have updated the BMS version since it was not supporting Narada batteries

 

[houseofancients]

anyway f21 is a dc bus over voltage error...
you panels are putting more voltage on the bus than what it can handle

 

[houseofancients]

i would suggest you look at the voltage comming into your mppt's and make sure it's not more than the rating....
watts actually is useless in this case , need to know the voltage ( VOC)

 

[InverterSpace]

i would suggest you look at the voltage comming into your mppt's and make sure it's not more than the rating....
watts actually is useless in this case , need to know the voltage ( VOC)

What is the solution to solve this issue? and how I can check the VOC and voltage

 

[houseofancients]

What is the solution to solve this issue? and how I can check the VOC and voltage

a multimeter would tell you the actual voltage of the string
the maximums are on the inverter label on the side ( it states 600, but i stay below 550)
use less panels in one string... or split the string

 

[InverterSpace]

a multimeter would tell you the actual voltage of the string
the maximums are on the inverter label on the side ( it states 600, but i stay below 550)
use less panels in one string... or split the string

I will check the voltage using a multimeter, but I didn't see where 600 was mentioned on the inverter. Furthermore, I have already split the 405-watt panel into an 8-panel string, which is connected to PV1, and in PV2, all 525 watts from the 14 panels are connected.

 

[InverterSpace]

today graph when error occured

 

[houseofancients]

I will check the voltage using a multimeter, but I didn't see where 600 was mentioned on the inverter. Furthermore, I have already split the 405-watt panel into an 8-panel string, which is connected to PV1, and in PV2, all 525 watts from the 14 panels are connected.

your VOLTAGE is the problem here.....

simply put , if you series a string ( + to - ) you add voltage, and one of your strings puts out too much voltage...

this really has nothing to do with watts ( watts = voltage x amps)

 

[houseofancients]

e

today graph when error occured

exactly, you string2 to is going over the maximum voltage that you mppt can handle

 

[InverterSpace]

e

exactly, you string2 to is going over the maximum voltage that you mppt can handle

thanks for your clarification, let me call my solar technician to fix the mppt string

 

[InverterSpace]

today my technician visited the site, and he mentioned that the panels are installed within the acceptable range. The error only occurs when we turn on the 3KW AC on the smart load L1. However, we were unable to reproduce the F21 error on the smart load L2, even with the same AC model. Additionally, we couldn't replicate the error with a high load on the smart load L3. The only notable difference is that we have a 1-ton AC running on the L1 as a normal load. let me know if you need any further details

 

[mikeinnyc]

https://www.deyeinverter.com
borked firmware
DeyeInverter
Homeass
interesting? The WritableRegisters.GridExportLimit register can be used if the grid export is not desired when the battery is charged and the PV generation exceeds the load.
tested with:

• SUN-12K-SG04LP3 / LSW-3

I would love to code this thing. I bet this is a beast when coded properly. Very few on git and that's not good because someone is the fall guy with coding. I'm probably going to get one of these beasts. looks awesome. Looks like this is the beginning stages so place this outside of your house ?UL rated