24 volt LifePo4 system with giandel inverter intermittent failure

[John Frum]

Lights, water pump. All 12 volt stuff works.

But no 24 v stuff works. nothing works via the inverter. no plugs.

The only 24 volt loads are the inverter and the buck converter, confirm?
Is the solar charge controller providing current at this moment?

 

[gives11]

The only 24 volt loads are the inverter and the buck converter, confirm?
Is the solar charge controller providing current at this moment?

Yes correct

 

[John Frum]

Yes correct

I asked 2 questions please answer both.

 

[gives11]

I asked 2 questions please answer both.

The only 24 volt loads are the inverter and the buck converter, confirm?
yes
Is the solar charge controller providing current at this moment?
photo attached of what I get on voltage meter.
photo of solar controler readings

 

[John Frum]

The only 24 volt loads are the inverter and the buck converter, confirm?
yes
Is the solar charge controller providing current at this moment?
photo attached of what I get on voltage meter.
photo of solar controler readings

Please disable the solar charge controller and see if the dc lighting stays on.
Then report results.

 

[gives11]

Please disable the solar charge controller and see if the dc lighting stays on.
Then report results.

when I disable solar charger lights etc don't work.

 

[gives11]

when I disable solar charger lights etc don't work.

 

[John Frum]

Are you running the buck converter off the scc load port?

 

[gives11]

Are you running the buck converter off the scc load port?

yes I am

 

[John Frum]

yes I am

Well then, that won't tell us what I want to know.
Can you enable the load port, we expect the dc lighting to come back on.
The remove one of the solar panel leads so that the solar charge controller does not recieve any energy from the panels.
See if the dc lighting goes out in that scenario.
Then report back.

 

[gives11]

done that. No income from panels. dc light stays on

 

[John Frum]

done that. No income from panels. dc light stays on

Try to power up your inverter and see if the dc lights go off.
The report back.

 

[gives11]

inverter won't come on
and dc lights stay on / don't go off

 

[John Frum]

inverter won't come on
and dc lights stay on / don't go off

What is the dc voltage at the inverter dc terminals as measured by your reference dvom?

 

[gives11]

26.5v

 

[John Frum]

26.5v

I think we have isolated the problem to the inverter.
Suggest you have Giandel support read this thread.

 

[John Frum]

Your inverter is rated for 24 volts confirm?

 

[gives11]

thats right

 

[gives11]

picture of inverter which can handle 32 v i think

 

[John Frum]

picture of inverter which can handle 32 v i think

System voltage should never get that high

You BMSs should be set to...
cut off at 3.65 volts per cell or 29.2 volts for the pack
also cutoff at 2.5 volts per cell or 20 volts for the pack

Your charger should be set too..
bulk=3.55 per cell or 28.4 for the pack
float=3.35 per cell or 26.8 for the pack

 

[gives11]

its never gone above 26.5

At this stage I don't know how to set the batteries. I've asked the supplier for help as I need to access the bms. "UMXLI BMS"

 

[John Frum]

its never gone above 26.5

At this stage I don't know how to set the batteries. I've asked the supplier for help as I need to access the bms. "UMXLI BMS"

They should already be set to what I specified, its very common for an LFP BMS to be factory set to those values.

 

[gives11]

They should already be set to what I specified its very common for an LFP BMS to be factory set to those values.

Massive thank you for your time. New technology for me and my instincts told me it was the inverter but to have you isolate the problem is a major help.

I've emailed the thread to Giandel. I will post on here the outcomes.

In the meantime I'll reconnect my old 12 v inverter.

Really wanted it to work as the wife's coffee machine doesn't work on the old converter but thats an issue for another thread or forum.

 

[Bud Martin]

BTW, I see the cheap black circuit breaker with the red button, is it used for the inverter?

 

[elGriffo]

BTW, I see the cheap black circuit breaker with the red button, is it used for the inverter?

Hi Bud, just about to use one of these, 250A $65 from Altronics, is there a problem with them?