janco93

Im so sorry for bothering you all, i will now copy paste here what artifical inteligence write to me when i was asking about it. Im notnsure if it is right or wrong, it is quite long piece of text but for me it makes a sence but i dont trust it 100% that is why im asking here in forum. AI chat : (We've reached the absolute core of the issue, where at first glance, electrical engineering logic dictates this is an unsolvable "Catch-22." Your reasoning is flawless in that if the current split like this through a standard domestic Residual Current Device (RCD), it would trip immediately. But here is the key to why this actually works on Deye inverters in "Common Neutral" mode without throwing a leakage current error (Leakage / F24). The entire secret lies in the inverter's hardware architecture and EXACTLY WHERE and WHAT the internal sensors (RCMU) measure. 1. Where is the RCMU sensor located in the inverter?Your concern stems from the assumption that the inverter has a leakage sensor directly on the Load N and Grid N terminals, measuring the physical current flowing through them. However, this is not the case. The internal RCMU (Residual Current Monitoring Unit) in hybrid inverters does not act as a standard domestic RCD for the bypass circuit. Its regulatory and technical purpose (according to the IEC 62109 standard) is to protect the AC grid from direct current (DC) and high-frequency leakage that could infiltrate from the PV panels, battery, and the inverter's IGBT power bridge. Therefore, the RCMU sensor is physically located at the output of the power inverter (after the generation stage), before the circuits split via the internal bypass relays to the Grid and Load terminals. 2. What happens during grid operation (Bypass Mode)?Imagine you have a "Common Neutral" setup wired—meaning both Grid N and Load N are bonded at your main domestic PEN busbar. You are connected to the grid and turn on an appliance in the older (TN-C) part of the house. The operating current flows from the grid, passes through the Grid L terminal, goes through the closed internal bypass relays in the inverter, and exits via Load L to the appliance. It returns via the old wiring (PEN) to your main distribution board onto the massive PEN busbar. And here's the trick: From here, 99.9% of the current flows straight out through the thick main cable back to the grid (street). Only an absolute fraction of the current would theoretically "loop" through the parallel connection of Load N -> inverter -> Grid N, because the voltage potential difference across a single solid copper busbar is practically zero. 3. Why doesn't it throw an error?Deye doesn't detect any "Leakage" because: It bypasses the sensor: The operating current flowing from the grid to the appliance and back (bypass) doesn't pass through the inverter's active power bridge at all. Consequently, it doesn't pass through the internal RCMU coil that would be looking for asymmetry. Power measurement is on the phases: The inverter measures the operating currents and household power consumption using its own Current Transformers (CT), which are placed solely on the phase conductors (L1, L2, L3). The inverter doesn't care at all which path the current takes to return to the distribution transformer; what matters to it is only what it measures on the phases relative to neutral (voltage). 4. What about battery operation (Off-grid)?When the grid goes down, the inverter starts generating power itself (via the aforementioned power bridge). Power flows from the bridge -> through the RCMU sensor -> out through Load L. It passes through the appliance and returns to your PEN busbar. Since the grid is disconnected, the current must return to the source, which is now the inverter. From the PEN busbar, it travels via the neutral wire to the Load N terminal and back into the power bridge. The RCMU sensor inside the inverter sees that, for example, 10A went out on the phase and 10A returned on the neutral. The vector sum is zero. The inverter is satisfied, reporting no leakage. Summary of this paradoxNothing multiplies, and no error pops up. Your concern would be 100% justified if you ran Grid N and Load N through an external 30mA RCD in the distribution board—that would trip in a heartbeat. However, the Deye inverter hardware inherently handles this topology (Common Neutral) without error messages because its internal leakage detection system is not designed to monitor the return path of bypass current, but exclusively to monitor its own power generation. This is exactly how hundreds of hybrid solar systems are successfully running on older grid systems (TN-C) across Europe.)

In that case i cannot connect this old pen part to backup load N, my intend was to put trough backoup load whole house because inverter and batteries are strong enough and also solar was way to not loose power during blackouts. So there is no way of connecting this inverter to my home to also provide backup while grid outage? If we go into extreme is it legislative problem ot also technical problem?

Problem is when i will connect output N from inverter back to the main fuse box what i think i must because it is output, then it will automaticaly connect to the PE because there is connection there also it will automaticaly be connected to the PEN, so also it will create N input and N output connection also N to PE connection. Also if PEN cannot be switched it cannot go only to the inverter in so im super confused about that. But i think it is the only way how to connect it, but im scared that something may happed to inverter or some error will cause not working in that connection. How people do connect these inverters in old house grid? Thank you for your responce and please reply again if you have any suggestions ho to do it.

Hi all i need your help, i have deye sun 15k sg05lp3 eu sm2, and i really dont know what to do with Grounding and neutral. Here in Slovakia we have L1, L2, L3 and PEN also my old house is using only 2 cables in outlet. So i think that there is some regulation that i shouldnt put my PEN cable trough any contactor or switch so this means that i must connect PEN to the input side of inverter and N output of load side of inverter together. Will it be a problem for grid or inverter? Just for info i have my earthing rods connected to PEN from grid. So for recap i want to connect earthing with PEN form Grid with N input to inverter and N output (load) of inverter.

Try disconnect panels from your inverters and leave only one, it solves my problem, but you need to connect rest of panel somehow differently

Ok so i can confirm, if i disconnect one of inverter solar input and connect to separate charger everything work great. So solved problem for now but itnis not ideal solution for me, anny suggestions to how connect it back and not flicker? 😀

Ok so status update, if i turn both on with solar available it flickers, if i disconnect solar from one of them is stops flicker.... Sun is going down so i cant 100 confirm but it seems like it is doing only if there are both inverters connected to solar. I have one more spare charger so i will try to disconnect one inverter from solar and put it to charger, i will let you know the results.

When it is reading different in output it aslo reading differen input, that is super weird. I have also tried to move signal cables more away from solar cables to avoid noise but it did not help at all.

Here is same voltage, one is off

I think that it should not be a problem because if there is no solar power available everything work great, no voltage fluctuations no flicker.

I have also notice that input grid reading is getting off too during this parallel operation, but as well only when sun awailable. With only one of them active all good.

Inverters are same firmware, strings are different one is about half smaller and on flat roof same direction.

Hi all, im having fliclering problems with my inverters. All works fine if only one is powered on, if i power on second inverter and sun power is awailable l, voltages on invertes start to vary abot 5 volts, power delivered by them is inconsistent one is delivering 1200 sencond 800 an it is changing, a can see it on led lights how inverters fight. It get worst when power is greater it flicker almost i would say no power for 0.1sec. but if there is dark outside and it works obly with batteries all is good, no voltage and power differences between them. I have tried to put ferite cores on all possible cables to get rid of noise but it didnt helped, aso tried to restart them and change main and slave, nothing helped, they woked fine while on they own too. Just paralel while sun is problem. Could some provide some help please?