Fed up with Growatt

[tfb]

Original install was 2 x strings of cells, 2 x SPH500TLBH inverters one of which had 2 x GBLI 6532 batteries.
What I wanted was to parallel the two inverters so each could have a battery and would give me 6KW total discharge
But, you need a SPH500TLBH-UP inverter to parallel and a SEM to manage them.
Anyway, I managed to get hold of them and got them installed and after a lot of faffing with Growatt support got them talking to the batteries and both talking the SEM, then overnight one wont talk the SEM anymore.
Lots more problems, the main one being PV voltage too high on both inverters and Grid voltage errors on one.
OK, so revert back to old system and I'm still getting PV voltage too high errors. It's reading upto 560V and spec is 550V. But I haven't played with the panels and it never did that before. Any ideas what I have done?

Failing that, I'm fed up with Growatt and would like to replace the two inverters BUT keep the batteries. So, any suggestions on a single inverter or a pair that will work with the growatt batteries, have a maximum PV input of 600V, and give me at least 6KW discharge from the batteries and let me limit export to the grid to 8KW and to add the cherry on top would allow me to monitor locally without the need to connect to a remote server???

Any thoughts would be appreciated
TFB

 

[Q-Dog]

Original install was 2 x strings of cells, 2 x SPH500TLBH inverters one of which had 2 x GBLI 6532 batteries.
What I wanted was to parallel the two inverters so each could have a battery and would give me 6KW total discharge
But, you need a SPH500TLBH-UP inverter to parallel and a SEM to manage them.
Anyway, I managed to get hold of them and got them installed and after a lot of faffing with Growatt support got them talking to the batteries and both talking the SEM, then overnight one wont talk the SEM anymore.
Lots more problems, the main one being PV voltage too high on both inverters and Grid voltage errors on one.
OK, so revert back to old system and I'm still getting PV voltage too high errors. It's reading upto 560V and spec is 550V. But I haven't played with the panels and it never did that before. Any ideas what I have done?

Failing that, I'm fed up with Growatt and would like to replace the two inverters BUT keep the batteries. So, any suggestions on a single inverter or a pair that will work with the growatt batteries, have a maximum PV input of 600V, and give me at least 6KW discharge from the batteries and let me limit export to the grid to 8KW and to add the cherry on top would allow me to monitor locally without the need to connect to a remote server???

Any thoughts would be appreciated
TFB

Are you saying you run each inverter on it's own independent battery bank? The batteries are not tied into one single bank?

 

[Crowz]

If your getting anywhere NEAR the 550v limit that's on you. You shouldn't see more the 500 V or a bit more normally so you can take into effect lensing effects on slightly cloudy days. If you don't take that in effect you will go over the 550v limit and eventually fry something.

Get the top voltage down.

 

[12VoltInstalls]

getting PV voltage too high errors. It's reading upto 560V and spec is 550V.

What does your single-strings measure on a VOM?

any suggestions on a single inverter or a pair that will work with the growatt batteries

I do not ‘know’ these batteries
But most batteries can work without bms communication to the AIO, just without the data reporting / SOC measurement

 

[kommando]

On the inverter with the grid voltage issues, is this showing as grid volts too high. Your AC cable may be too long for the size and when the inverter feeds in at peak output the voltage will climb if there is a wiring restriction, so AC wire needs to be increased in size.

 

[12VoltInstalls]

The batteries are not tied into one single bank?

Q?: isn’t it normal for the integrated battery/AIO to be parallel in some way between the two AIO “inverters?”

 

[Q-Dog]

Q?: isn’t it normal for the integrated battery/AIO to be parallel in some way between the two AIO “inverters?”

I don't quite understand what is happening. I always though in order to parallel inverters they needed to be on the same battery bank?

 

[Q-Dog]

Can you post a link to the inverter? I can't find the model # you posted on the Growatt site.

 

[12VoltInstalls]

I don't quite understand what is happening. I always though in order to parallel inverters they needed to be on the same battery bank?

Well you know my question LOL

So there has to be some battery parallel if each battery has its own comms to a pair of AIO’s, right?
Otherwise the two banks would a) not share load b) risk LVD “dropping a phase” c) not charge equally if one side or the other gets shaded strings.

(That’s what the distributor indicated re: a pair of LV6548’s for split phase I’m about to do over two parallel 5kWh 48V batteries for each 6548. Told me I could “be creative.”)

 

[Zwy]

Original install was 2 x strings of cells, 2 x SPH500TLBH inverters one of which had 2 x GBLI 6532 batteries.
What I wanted was to parallel the two inverters so each could have a battery and would give me 6KW total discharge
But, you need a SPH500TLBH-UP inverter to parallel and a SEM to manage them.
Anyway, I managed to get hold of them and got them installed and after a lot of faffing with Growatt support got them talking to the batteries and both talking the SEM, then overnight one wont talk the SEM anymore.
Lots more problems, the main one being PV voltage too high on both inverters and Grid voltage errors on one.

Confusing to say the least. Anyway, regarding the SEM, I found this. https://diysolarforum.com/threads/a...ps-running-them-in-parallel.68797/post-905136 Might help you understand why one doesn't talk anymore.

OK, so revert back to old system and I'm still getting PV voltage too high errors. It's reading upto 560V and spec is 550V. But I haven't played with the panels and it never did that before. Any ideas what I have done?

Yes, you have too many panels in series. The unit rated up to 550V. Did you run panel specs with temp co efficient thru a calculator?

Failing that, I'm fed up with Growatt and would like to replace the two inverters BUT keep the batteries. So, any suggestions on a single inverter or a pair that will work with the growatt batteries, have a maximum PV input of 600V, and give me at least 6KW discharge from the batteries and let me limit export to the grid to 8KW and to add the cherry on top would allow me to monitor locally without the need to connect to a remote server???

Any thoughts would be appreciated
TFB

 

[Zwy]

Can you post a link to the inverter? I can't find the model # you posted on the Growatt site.

It isn't correct in his post, it should be Growatt SPH5000 TL-BH but any info I found had the UP at the end.

 

[tfb]

I'll try and answer as many of the comments in one...with some drawings too.
The system was installed before we moved in and was like this. Sorry got the H wrong in the model number

https://photos.app.goo.gl/GnReWKoTciysv2jaA


A signle string connected to each inverter and two batteries on one inverter. The system worked without error, but inverter with the batteries could only discharge at 3KW and that meant that we were importing when we still had charge in the batteries and the 4 hour off-peak window at night was not enough time to fully recharge the batteries.


So. my idea was to move one battery to the other inverter, but for that I needed the SPH5000 TL BH UP version of the inverter and a SEM.

After getting hold of the UP version and a SEM I ended up with this layout.

https://photos.app.goo.gl/L6i4uC1Tsx9FL7Yq6

I had problems getting both inverters to talk to the batteries at first, but growatt support eventually gave the the anwser (RJ45 with pin 4-5 shorted to be fitted at all unused ports on the batteries)

Then one of the batteries started charging from the grid (they were at about 75% charge) when in Load 1st mode they should have been discharging. The other batttery didn't do anything

Then I started to get PV voltage to high errors - measured the voltage with a meter and it was getting to 560VDC at times. Yet, the strings hadn't been touched other than unplugging from the old and plugging into the new. Impossible to mis-wire the strings due to cable lengths.

With regard to the grid voltage too high, the upper limit on the inverter is set to 260VAC, I never measured more than about 244VAC unless it may have been very transient.

I was under the impression that the SEM should manage the charging/discharging of the batteries by talking to each inverter and preventing the batterys from charging each other.

So, have reverted back to old system and still getting the High PV errors....
These High PV errors have really confused me. The voltage is high, but the strings haven't been touched and I really don't fancy getting on the roof to split each array into to seperate strings. No calcs were done by me as it was working without errors before and the spec differnce between the TL BH and TL BH UP doesnt change the PV requirements.

Thanks
TFB

 

[12VoltInstalls]

measured the voltage with a meter and it was getting to 560VDC at times

If your getting anywhere NEAR the 550v limit that's on you. You shouldn't see more the 500 V or a bit more normally so you can take into effect lensing effects on slightly cloudy days. If you don't take that in effect you will go over the 550v limit and eventually fry something.

Get the top voltage down.

Do that first.

(why do you think you need such high voltsge?)

What are the panel specs?

If you have 24 300W panels for example:
-why not do 6 panels in series twice and parallel two strings on each inverter?
(6S2P)
That will cut your voltage down to ~240V and solve that.

but the strings haven't been touched and I really don't fancy getting on the roof to split each array into to seperate strings. No calcs were done by me as it was working without errors before

That doesn’t make it right, just unexplainably lucky.

With regard to the grid voltage too high, the upper limit on the inverter is set to 260VAC, I never measured more than about 244VAC unless it may have been very transient.

This is not a 120V/120V aka North American split phase?

 

[tfb]

Do that first.

(why do you think you need such high voltsge?)

What are the panel specs?

If you have 24 300W panels for example:
-why not do 6 panels in series twice and parallel two strings on each inverter?
(6S2P)
That will cut your voltage down to ~240V and solve that.

That doesn’t make it right, just unexplainably lucky.

This is not a 120V/120V aka North American split phase?

Nope, UK based

I don't think I need such a high voltage, but whoever designed/installed may have had a reason - though what it may be is beyond me.

There are two strings of 15 panels - no idea of the spec for them as very little documentation was left behind -cert tells me the p/n is ENSP54M2395 and googling the number doesn't give much. I like the idea of splitting the strings....with the exception of getting on the roof to do so.

Today was clear skies at time, but last summer would have been more direct sunlight at times. Looking at fault logs for the last year, prior to this event

Event Type	Date	Event ID	Description
Fault	2023-12-01 12:45:13	6-12-0	PVVoltHigh_Fault
Fault	2023-12-01 09:55:10	6-12-0	PVVoltHigh_Fault
Fault	2023-11-30 09:29:54	6-12-0	PVVoltHigh_Fault
Fault	2023-11-29 09:34:00	6-12-0	PVVoltHigh_Fault

were the only faults. and solar generation was at zero to 300W either side of those times.

TFB

 

[12VoltInstalls]

no idea of the spec for them as very little documentation

So the backside of the panels will have a label that gives important info. I’m gonna guess those are ~ <40VOC panels. But you need the other label info

measured the voltage with a meter and it was getting to 560VDC at times

was that open circuit or loaded?

 

[kommando]

I have been getting over 100% of the pv panels rating on cold late mornings with full sun recently. The cold is responsible and the pv voltage will also be over the rating. On hot days the efficiency drops and your hi volt faults will be gone. But best to get the voltage down by rearranging the panel connections.

 

[tfb]

So the backside of the panels will have a label that gives important info. I’m gonna guess those are ~ <40VOC panels. But you need the other label info

was that open circuit or loaded?

connected (measured at isolator), but I think open as the inverter was in fault mode at the time and I suspect there is an internal disconnect as the display showed 0V. The dispay on the inverter shows 500+ VDC when the sun comes out and everything is working.

 

[tfb]

I have been getting over 100% of the pv panels rating on cold late mornings with full sun recently. The cold is responsible and the pv voltage will also be over the rating. On hot days the efficiency drops and your hi volt faults will be gone. But best to get the voltage down by rearranging the panel connections.

possible, but the generation records show that it was low (zero to 300W) either side of the events - can't see it suddenly peaking in such a short time window - but willing to proven wrong.

Looks like I'm going to have to get out the ladders

 

[12VoltInstalls]

can't see it suddenly peaking in such a short time window - but willing to proven wrong.

Consider it proven.
That’s what happens.

 

[kommando]

but the generation records show that it was low (zero to 300W) either side of the events

That's not the volts, the volts can be high but the amps really low, its these cold spring mornings that are giving you high volts just as the sun gets strong but the panels are still cold.