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
Spelling looked like that of a pre-schooler...

[Brian_SA]

Hi Guys

 

I have infinisolar and had this headache...but finally solved it on my side. My inverter was constantly pulling 80watt from the grid and fluctuated a bit with loads, but the grid was always being used.

What worked for me is to set the inverter in "Off Grid III" when the grid relay is not connected in inverter mode.

 

You still have the grid to support you and to top up the battery when required. So you won't be without power in this mode, and you won't used the grid at all as long as your PV and battery can support you.

 

Let me know if it works for you as well. 

[Steve87]

The Infinisolar is just a settings nightmare...but glad to see many are starting to get the best out of these machines. That Grid relay is a very important topic with the infiniSolar. Basically means the Grid will assist or not. In other words it will either trip when the max capacity of the inverter is reached or it will bypass & use Grid Assist. 

In all cases with the grid offline like loadshedding the inverter will trip when any phase in the case of a 3phase machine reaches its capacity. Eg 10kW Infini, will trip when loadshedding & more than 3.33kW is demanded on any phase. 

Pay attention to the Grid relay in the manual, they trying to tell us something important here. 

[Brian_SA]

Thanks Steve

I have 2 units, will connect the second soon so I do not worry about overload, 10kW is plenty for me.

 

I just seen a lot of people have been complaining of the constant grid usage, so it's a good starting point to see if it works for you, if you rely on the grid constantly I suppose you have to live with the reference load from the grid. Another way I have read is to set the grid compensation power to the same as your inverter load, it balances it out to practically 0, but then you still have the fluctuations present when your loads vary all the time, but at a stable load it basically stays at 0.

 

Thanks

[Steve87]

Within each mode there are settings like load priority. Making changes to these will influence the outcome of grid use. 

Having 2 machines helps a lot. The new Infini series soon to be released as Segen Blue mountain machine has some major nice updates: phase sharing of up to 150% without the Grid so they have overcome this nuisance trip problem. Also 2 AC outputs that one can remotely turn on or off, not to mention Lithium BMS support like the other Voltronics machines. The next generation Infini is how they should have been built. Got to credit Voltronics at least they getting their products better as time goes on. 

Enjoy the Green machines Brian

Edited October 18, 2022 by Steve87

[Brian_SA]

Hi Steve and others on this thread.

I decided to go have a peak at the ''grid relay'' function when in off-grid mode.

The manual says as follows when using grid relay(off-grid mode I & II):

PV power will provide power to the load first and then charge battery. Feed-in to
the grid is not allowed under this mode. At the same time, the grid relay is
connected in Inverter mode. That means the transfer time from inverter mode to
battery mode will be less than 15ms. Besides, it will avoid overload fault because
grid can supply load when connected load is over 5KW.
 

the manual says as follows when not using grid relay(off-grid mode III):

1st Load, 2nd Battery
PV power will provide power to load first and then charge battery. Feed-in to the
grid is not allowed under this mode. The grid relay is NOT connected in Inverter
mode. That means the transfer time from inverter mode to battery mode will be
about 15ms. If connected load is over 5KW and grid is available, this inverter will
allow grid to provide power to the loads and PV power to charge battery.
Otherwise, this inverter will activate fault protection

So it seems you will have the grid as backup in both cases, the only difference is the transfer time involved, if I understand correctly.

If you want the transfer time to be less than the 15ms, you will have to accept that the grid will always be connected and pulling around 70watts of power in my case and oddly supply the load fluctuations in power at short bursts.

As for my setup, I have no problem with the grid relay not being connected, this allows my grid to have 0 power consumption from the inverter line as long as my batteries are sufficient and no overload occurs.

It might be different for each individual here, especially if you export to the grid, which I have no experience in.

 

Cheers!