Infinisolar use grid when it should not

[Daniemj]

My infinisolar 5 kw inverter use a little bit of grid power every now and then during the night when it is supposed to carry the load on battery only.

This happens when the inverter is both on "Grid-tie with backup IV" as well as "Grid-tie with backup III". It might also do it on some of the other settings, but these are the two that I am currently using. It does it less with backup IV. In backup III it used a lot of grid power once PV start to produce power (switching from pv unavailable to pv available mode). I actually preferred backup III because I can delay the battery charging to later during the day, but it uses more grid power compared to backup IV which is exactly  what I don't want.

 It does not seem like a lot, but it does use more than 1kWh from 21h00 till 07h00. I suppose I can switch the Eskom feed to the inverter off at night once it is on batteries, but then I do not have the grid backup and also that is not how it is supposed to work. It is almost as if it is getting worse lately. It did not do it so much a while ago.

Should I maybe consider a firmware upgrade, or maybe do a power off on the inverter to do a kind of reset? 

[dargslan]

Hello,

I see the similar problem with my Infini 3kW+. I do not possess any advanced sofware yet, just stick with solarpower

and observation. I use grid tie with backup (II) mode, charge battery from PV only, no grid backfeed (PV first load, then charge bat.)

I found that when I turn the grid swith OFF during battery charging (max 25A) the level of PV input rises about 200W +-,

so that shoud be its own power consumption during max charging which it should get from PV, but uses grid instead.

Also during night when on battery, if grid is ON, the overall power drained from battery is considerably less then when

I switch the input grid OFF (I guess about 1-1,5kWh).

I would appreciate if there is some setting to reduce the self-consuption or kill it entirely so the inverter will drain power only

from battery or PV and use grid power only if the battery is very low.

 

If I use the grid swith OFF, it functions all well (in the time with sufficient PV input  + - from spring to autumn), but there is no immediate

backup if the battery drains too much.

Thaks for any advices.

 

[ChristoSnake]

I also have an InfiniSolar, and when you run them in grid-tie mode they always tend to consume a bit of grid power.

My best guess why this happens at night is that there may be some fluctuations in the grid voltage that cause them to "overshoot" or "undershoot" while trying to balance their own voltage to that of the grid.  During the day it is triggered by changes in load, such as turning a kettle, pool pump, geyser element, etc. on/off.

The only sure way to ensure this does not happen is to change them to run in off-grid mode, but that defeats the benefits of owning a grid-tied inverter....

Edited April 6, 2020 by ChristoSnake
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