Growatt 48V SPF 3000TL LVM restarting/glitching

[taniman]

I have 3x Growatt 48V SPF 3000TL LVM connected to 3 phase
1 Inverter for each phase.

Connected also are 6x growatt Ark 2.5L-A1 Batteries

PV System 12x 380Wp pannels

The system seems to work well when we got sun and the batteries are charged just fine.
But as soon as the system goes into battery mode, it seems something happens.

The Inverters would just restart. Output goes to 0, and then after about 30 seconds or so it comes back on.

There are no fault codes, no warning codes or anything so make investigating this easier.

If we use Grid Bypass (UTI 01) to run the house through the inverters also it works fine.


Some of the settings
01- SBU (Output source priority)
03 - APL (AC input voltage range)
05- LI (Battery Type)
08 - 120V (output voltage)
09 - 50Hz (output frequency)
12 - 50% (voltage point back to utility source)
13 - 95% (voltage point back to battery mode)

Video of the Inverters on Bat. First but failing and dropping to Util and then back to battery.

 

[timselectric]

Sounds like an issue with the battery.
Not seeing a code, because it is resetting after power loss.

 

[timselectric]

Is the battery below 50% , when this is happening?
Can't really see it, on my tablet very well.

 

[taniman]

Is the battery below 50% , when this is happening?
Can't really see it, on my tablet very well.

The batteries were above 90%. Usually it starts behaving strangely around 95% when it needs to kick into some mode or something

This morning I tried again and it happened also with battery power at 88%

The battery has never really seen power below 80% cause it get's charged just fine.
It also discharges while on Grid power.
So every morning it recharges back to 100. Then system starts using PV + Battery, but at a certain point it switches to only Battery power and then it happens usually.

 

[timselectric]

That is strange.

 

[timselectric]

I don't have any ideas, right now.
I'll sleep on it. But hopefully, someone else will have a solution for you. Before I wake up.

 

[schmism]

try battery type USE (05) and disconnect the communication between the battery and the inverters.

If it works then you know it has to to do with the battery communication etc.

 

[taniman]

try battery type USE (05) and disconnect the communication between the battery and the inverters.

If it works then you know it has to to do with the battery communication etc.

Unfortunately this did not help either. The Growatt Batteries seem to require BMS connection.
If the cable is not connected or connection is not recognized the batteries will go into an error state after 5 minutes or so.

 

[taniman]

Been at it for almost the whole day.
I trully do not get it, the inverter or the battery will just drop output voltage to 0. And then connect back.
What's funny is that the Inverters are currently on battery only, and when this happens they don't turn off.

So it seems they are still getting power from the batteries. But still the whole house loses connection when the output drops to 0.

 

[timselectric]

How are the batteries wired?

 

[timselectric]

All batteries paralleled to bus bars, with equal length and size cables?
All inverters paralleled to bus bars, with equal length and size cables?

 

[taniman]

They are wired like so.

Side note, I have also been testing them with just 1 battery. Cause I thought maybe one in the series could have a problem.

Just as a reminder I have 3 Inverters 3P1, 3P2, 3P3. Maybe the battery does not like that too much?

 

[timselectric]

Are you using current sharing cables?
Probably not, with one inverter per phase.

 

[timselectric]

Battery cables need to be the same length to each inverter. Otherwise, the voltage drop will be different. And the inverters will not see the same battery voltage. Which will confuse them.

 

[timselectric]

When this happens, is grid power available to the inverter?

 

[taniman]

Are you using current sharing cables?
Probably not, with one inverter per phase.

correct, I am not as that is not allowed when using 1 inverter per phase

Battery cables need to be the same length to each inverter. Otherwise, the voltage drop will be different. And the inverters will not see the same battery voltage. Which will confuse them.

I would need to double check that. But I think the cables to the inverters it self might be a bit different

When this happens, is grid power available to the inverter?

I have grid turned off currently, but a few days ago when it happened while I was out, at a certain point it indeed did a fall back to grid power. but that was after 6 dropouts or so.

The baterry supplied power cables go here, where we split the power to the inverters

 

[timselectric]

I would check battery voltage at the inverter terminals, under a medium or higher load.
To see if they are identical.

 

[timselectric]

Also
If it only happens when switching to battery/ inverter only mode. There could be a grounding issue.
To test for this. Turn off all loads. Switch to battery only mode. If it holds, turn on one breaker at a time.
This will indicate which circuit is causing it.
(If, this is the issue)

 

[taniman]

I would check battery voltage at the inverter terminals, under a medium or higher load.
To see if they are identical.

Thank you, I will try this out in the morning see what it does. With higher load

Currently it's only using battery to power the inverters and it shows like this. Already a small difference

 

[timselectric]

I would check with a meter, at the terminals.
Don't trust the display.