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JK BMS triggerings Short circuit protection

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mihastare

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Jun 5, 2021
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I have just changed my old DALY BMS with a brand new JK B2A8S20P. Everything works flawlessly
BUT
When I turn ON my inverter, it triggers Discharge Short Circuit Protection.

Probably inverter when powering ON pulls too much Amps and it triggers it.

What can I do?

It definitely is not short-circuited as nothing changed except BMS. Cables are fine, all others breakers are fine, only BMS triggers.

Do you have any suggestions?

Thank you!!!
 
On the JK PB BMS I changed the short circuit time from 1500ms to 2000ms and the warnings stopped. I also have a pre-charge resistor but the postman took too long to deliver but its ready for next time.
 
Thank you for answers. I did change SCP time trigger from 1500 to 20 000 ms and it works now. Will test later, when inverter capacitors empties. But at least there is a solution.
 
If its up and running and you used 20,000ms not the 2000ms I used then change it now. You can always change it back but currently at 20,000ms you are not protected from a real short.
 
At 2500ms it triggered, than I changed to 20 000ms and it didn't (but it was already charged a little bit from 2500ms try just a minute before).
I will be testing every day another number to find the sweet spot.
But 2500ms for sure it has triggered.
 
You can use 20,000ms when you are switching on a discharged Inverter but you only need the setting for that event only. I only turn my inverters off every few months so keeping the 20,000ms for an event that occurs every few months but leaving you unprotected from shorts in between is not the way to go. Even if you find the sweet spot is 3000ms only keep that setting for turning on a discharged invert, revert to 1500ms once the inverter is connected and working. If you are switching your inverter off frequently then better to use the resistor to keep the MOSFETS life long.
 
kommando said:
You can use 20,000ms when you are switching on a discharged Inverter but you only need the setting for that event only. I only turn my inverters off every few months so keeping the 20,000ms for an event that occurs every few months but leaving you unprotected from shorts in between is not the way to go. Even if you find the sweet spot is 3000ms only keep that setting for turning on a discharged invert, revert to 1500ms once the inverter is connected and working. If you are switching your inverter off frequently then better to use the resistor to keep the MOSFETS life long.
Click to expand...
:( I turn my inverter ON only 1-2 times a day for few minutes (to run my 2kW blender). Other than that I use it only for charging my electric toothbrush. So I will need to keep this setting all the time.

I have no idea how to use a resistor :/ - how to wire it etc.

How so that DALY BMS had no problems at all? But there was no setting for SCP ms.
I'm thinking of buying JBD BMS hoping not to have this issue.
 
Hello, I have the exact same issue. I had (3) Daly BMS in parallel and switched to JK BMS and now I have this error. I thought I had an inverter issue so I ordered and installed a new power board. I'm new to this forum so I wish I'd have checked here first. I have (5) 100V-6800mF caps. Can you Please explain the exact procedure for using the resistor. Wattage, ohms, where to connect both ends.
 

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