FoxESS Community - Owners & Installers Forum

Hi,

i have the following problem. My inverter H3-5.0E may have a problem on sunny days. Especially in the morning.
When it is cloudy weather there seems to be no problem.

To workaround or temporary fix the problem i have to make a reset on the DC Switch on the inverter.

PV-Configuration:
13xJAM54D41LB PV panels with 430-440 watt

Inverter: H3-5.0E
Inverter Firmware
Master : 1.95
Slave : 1.03
Manager : 1.80

The initial weather situation in the morning is as follows (sunny, no clouds, some panels are partially shaded, one completely): This values are shown in the PV Display before i reset the DC switch: When i reset the DC switch from "on" to "off" and back to "on" again the inverter shows the right values and the PV Output is correct! What can be the problem? Software Bug? Electronic issue? Maybe try to change to another MPPT? Any ideas?

Regards

It looks like your installer has put all of your panels on one MPPT (approx. 33v x 13 panels = ~425v), which is strange in such a setup. It would probably have been a better idea to have each side of the dormer on their own MPPT as it could be the shading or over-panelling causing this. The other issue is that the H3-5.0-E has a max DC input of 4000W (and 14A) per string, which you will be exceeding at times (13x 420w panels would be 5460W for example).

Does it still happen when the sunshine is shining straight on and there is no shading?

reef wrote: ↑Thu Sep 05, 2024 11:40 am It looks like your installer has put all of your panels on one MPPT (approx. 33v x 13 panels = ~425v), which is strange in such a setup. It would probably have been a better idea to have each side of the dormer on their own MPPT as it could be the shading or over-panelling causing this. The other issue is that the H3-5.0-E has a max DC input of 4000W (and 14A) per string, which you will be exceeding at times (13x 420w panels would be 5460W for example).

Does it still happen when the sunshine is shining straight on and there is no shading?

Hi,

installer added 9 panels to one String (9x430 Watts = 3870W). I added 4 more same type panels to the existing string (4x 440 = 1760W). So The string can produce maximum peak @~5630W.
You are right saying 2 Strings would be better. But the 4 new panels would be under the necessary 160V Input! So it wouldn't generate power on MPPT2.
Before installation i asked ESS Support if this setup is possible. They told me: No problem. The inverter will just cut off the DC to 4000Watts. It optimizes itself.
So, yes, the H3-5.0-E is now to small for the setup. The ESS support also suggests to change to inverter model H3-8.0-E (the 8KW version) It has 8000 Watts input on MPP1 and 5000 W on MPP2.

To your question:

Does it still happen when the sunshine is shining straight on and there is no shading?

=> When there is no shading the inverter shows maximum DC @ around 4000
It also outputs 4000 W when 1-2 Panels are partially shaded.

As you can see in the graphics the inverter cuts off to 4000 (the top of the mountain curve is missing) When i do not reset the Inverter in the morning the graphics (PV Power) looks as follows: You can see after ~12 o'clock AM the inverter suddenly powers up to 4KW. But, until 12 o'clock in the morning the PV Output is almost stagnant @400 W

But the main question remains: Why does the inverter collect the right PV values in the morning after DC reset? In my opinion the Software does not optimize the PV values internally. It also can be the MPPT1 has a defect?
Yesterday in the late evening i moved the string to MPPT2. I will have a look at it if it behaved the same.
So what would you do?

Switching to MPPT2 does not change anything. The problem still remains. Just did a reset on DC switch. From 390 Watts to now 1200 Watt. This is strange...

I Think i works good for now. Getting Master 2.01 and Manager /ARM 1.80 Update.