Good evening everyone, I am hoping someone could asssit me with this problem.

 

Two weeks ago I help my brother in-law install a 16Kw single phase Deye inverter with 3 x 5.12kw Deyness batteries and 18 x 550w panels in 3 strings.

Everything is running great, except when the power is out and he is trying to pull more rhan 3kw, the whole system trips and restarts and then gives a F56_DC_VoltLow Error.

I have contacted Deye support and they have done a remote firmware uodate, but the problem persists.

I have Googled to my wits end and the lots of people have the problem but no real solution. 

Wire the batteries to a bus, use 50mm² cable to the inverter, check for hot connections on your fuses. I don't think the contacts on those batteries were made for 300A.

Hi Frivan,

 

Thank you so much. Please excuse me, I am a newbie, haha 

So do you think a busbar and the 50mm cable will sort the problem out even though you think the connectors on the batteries were not designed for the 300amp?

Dyness are 0.5c. 

So with 3 batteries you shouldn't be drawing more than 7.5kw or so. 

So underspecced for the 16kw Inverter. 

 

But if 3 kw is giving the error that's due to something else. 

 

Check your battery discharge rate in the settings. May be the issue. 

If you look at 50a x 3 you should set it to 150A (recommended) . Or 75a x 3 (maximum as per specs which may degrade the battery over time) 

 

https://powerforum.co.za/topic/9564-sunsynk-with-pylontech-batteries-dc-voltlow-fault/

Edited May 30, 20233 yr by abd7

Hi abd7, thanks for the reply.

Inverter is set to 150amp discharge rate.

No setting we change on the inverter serms to help.

Do you also think it might be the battery cables? We are using the ones that came with the batteries. 

9 minutes ago, Jaco de Klerk said:

So do you think a busbar and the 50mm cable will sort the problem out even though you think the connectors on the batteries were not designed for the 300amp?

In a busbar configuration each battery connector will only see 100A. The inverter will connect to the busbar (via fuses). 

The other thing we have done just noe is set the dip switch on bat1 to 1 and on bat 2 and 3 al dips to off. Now it did not trip.

Could that have been the problem or are we just making the issues worse? 

Hi everyone, so we have found the problem.  So the dip switches seems to have only sorted out the problem for a short while and the problem came back.

The problem was BMS communication cable was plugged into the "Battery connector"  after plugging it in the RS485 port all issues went away and we can now pull over 5kw without any errors or tripping.

Thanks for everyone's help, I really appreciate it.