I got my Anenji 4kW 24V inverter installed alright, everything works nicely and I am testing and measuring the installation to make sure its 100% safe.

With power connected to the inverter and, regardless if its in bypass or battery/solar mode I measure 0V between output N and Ground which is what one would expect.

If I simulate a grid power loss (breaking Live line) I also get 0V which is fine..

The problem is I get ~120V if I disconnect both Live & Neutral .. this is the case where an RCBO connected at the input of the inverter trips.

As far as I know and from all I am told, an RCD/RCBO disconnecting both Live & Neutral is mandatory immediately after the main grid breaker and fuse here in Greece..

I know single pole RCBO do exist but they are not used or even sold locally here in Greece.. something like that would possibly solve the problem.

My alternative solution is to use a good quality industrial relay such as MC-32a by Metasol LG using its 2NO contacts to connect Live-Neutral to the inverter when grid is present and disconnect them when its no and use one of its NC contacts to connect Inverter's output Neutral to Ground when for any reason grid power is not present..

Do you think this will work? Is there any other workaround?

This is exactly what I have done with some other inverters:

It works well and is the best solution in my opinion. It disconnects AC Input to inverter so no chance of some kind of backfeed, and allows RCD to be used at output of inverter. Just remember that the N-G bond on the output needs to be before the output RCD (if you choose to install one on the output).

BTW: I would like to hear your opinions on this Anenji, I have one on order, waiting for it to arrive.

25 minutes ago, meetyg said:

BTW: I would like to hear your opinions on this Anenji, I have one on order, waiting for it to arrive.

So far I have i have finished the electrical installation but I don't have any panels to start normal operation :)

I do have 2 small 175W panels and an external mppt with which I am charging the battery (2x12V 300Ah) getting 1kWh on a good day..

I set it to operate in UTI mode meaning its an expensive UPS atm :)

But it does work nicely, even when I try to abuse it a little..

There are a few things to consider especially about battery and how much current you draw from it but so far I am more than happy with it

When I first got it I tried to plug it to grid to play with its menus etc but it didnt work.. I spoke with Anenji and they told me the units they sold last year didn't have an (AC UPS board) which they send me for free and once installed it works 100% as expected. Without it, if you don't have battery it will only work during the day

Then, once installed and wired I measured NG voltage but, with grid present it was always 0V regardless of power source.. when I disconnected grid though both L & N it showed 120V at its output N.

In Greece RCBO must disconnect both L & N so I cannot use a single pole one (I see those in UK?) and I must have one to comply with regulation.. but, with an RCBO at the input of the inverter in case it trips it will break NG bond so I came up with the solution of a relay with 2NO & 2NC ... someone just told me this might be "dangerous" and it is not safe to have the relays coil energized practically permanently etc.. which, to me is crap really when you use industrial grade relays ... the Metasol LG MC-32A is listed as relay for Power Plants FFS.. if its good for that use, its certainly good for mine!

Back to the Anenji, its 4kW only and I have set my battery to charge/discharge with only up to 1kW ... few days back I went to cook and turned on two appliances drawing 5.3kW! It simply went to bypass and worked for a few min without any problem, I then turned off one device to play safe.. the internal bypass relays are 40A rated though so nothing happened.. I plan repeating this "experiment" but with the inverter cover removed and having a thermal camera to see what is actually happening inside it. It should be fine ...

The other problem is that while you can set battery discharge current so you don't stress your battery this is problematic if there is no grid present at the time.. it simply ignores the setting so you must at least provide thick cables for the battery up to the inverter power rating to avoid them melting even if in normal use you only draw 1/4! I have installed a 63A fuse on the battery just to prevent this from happening.. this can be more elegant using current monitors and disconnecting part of the load if you can leaving only essentials..

Thanks for your reply.

It sounds weird that they didn't include that AC board. I will have to check mine.

Anyways, I am using these cheap contactors from Aliexpress:

https://www.aliexpress.com/item/1005001339814821.html

So far no issues, running 24/7.

An industrial one should probably be even better.

57 minutes ago, meetyg said:

It sounds weird that they didn't include that AC board. I will have to check mine.

They told me current stock comes with the AC PSU board

57 minutes ago, meetyg said:

Anyways, I am using these cheap contactors from Aliexpress:

https://www.aliexpress.com/item/1005001339814821.html

So far no issues, running 24/7.

The problem with this kind is 1. potentially coil noise 2. increased power consumption and 3. raising temperature also because of 2.

I have a similar available actually two.. same brand.. one big 63A and a smaller 25A.. applying power to the smaller one's coil works nicely, no heat no noise.. the big one is literally operating as a freakin' vibrator!

the one from LG is listed as "suitable for nuclear plants" so I hope it is in fact solid.. fun fact, exactly same "design" visually at least comes from at least couple much cheaper chinese manufacturers so who knows who manufactures what for whom or copies them... I plan including a 1A MCB for the coil power and a T2-T3 SPD for coil protection plus an indicator controlled by the leftover 1NC contact powered from inverter output.. would be ON when NG bond is established.. a second indicator will show when there is power going to the inverter from grid.. one on at a time.. should be more than plenty

I have a 25A version and it is fairly silent. Also not running very hot. Around 42 degrees Celsius with thermal camera, after running for a few weeks.

I don't think that these take alot of current after initial power to the coil. Some of the better quality ones have an optimized circuit to reduce the current and heat to the coil after initial start up.

One advantage to using a 2NC and 2NO in the same unit, is that even if the coil fails, and the relay closes, you will not trip the input RCD because input AC will be disconnected.

I bought a few spare item of these relays, in case I get a failure.

I like your idea of indicators!

21 hours ago, meetyg said:

I have a 25A version and it is fairly silent. Also not running very hot. Around 42 degrees Celsius with thermal camera, after running for a few weeks.

I don't think that these take alot of current after initial power to the coil. Some of the better quality ones have an optimized circuit to reduce the current and heat to the coil after initial start up.

One advantage to using a 2NC and 2NO in the same unit, is that even if the coil fails, and the relay closes, you will not trip the input RCD because input AC will be disconnected.

I bought a few spare item of these relays, in case I get a failure.

I like your idea of indicators!

I have never been bothered by coil consumption. If the draw is a problem then just sleep at night and use a bistable relay which changes state with each pulse.

https://www.elkoep.com/bistable-relay-br-216-20230v

On 2025/03/29 at 7:51 PM, meetyg said:

BTW: I would like to hear your opinions on this Anenji, I have one on order, waiting for it to arrive.

It works nicely .. I can easily recommend it.

On 2025/03/30 at 1:57 AM, meetyg said:

I have a 25A version and it is fairly silent. Also not running very hot. Around 42 degrees Celsius with thermal camera, after running for a few weeks.

I don't think that these take alot of current after initial power to the coil. Some of the better quality ones have an optimized circuit to reduce the current and heat to the coil after initial start up.

One advantage to using a 2NC and 2NO in the same unit, is that even if the coil fails, and the relay closes, you will not trip the input RCD because input AC will be disconnected.

I bought a few spare item of these relays, in case I get a failure.

I like your idea of indicators!

You can see my installation here

feel free to subscribe to the channel :)

got more videos on the electrical installation and neutral-ground bonding dynamically

Well, my Anenji had been working great for the past few months, ever since I got it.

I am amazed at how quiet it is, compared to many other all-in-one inverters I've tested.

It also works great with 2NO/2NC contactor for N-G bonding when grid is out. (one NC port is not used of course).

It's charging algorithm for Lifepo4 isn't perfect, but works alot better than others.

It also tends to over-report it's solar production by around 10% (reports around 100w more than actual, when supplied with almost 1000w of PV).

But other than that I'm pretty happy with it. I think my quest for searching of the best 24v all-in-one cheap (Chinese? ) inverter is finally over!

4 hours ago, meetyg said:

Well, my Anenji had been working great for the past few months, ever since I got it.

I am amazed at how quiet it is, compared to many other all-in-one inverters I've tested.

It also works great with 2NO/2NC contactor for N-G bonding when grid is out. (one NC port is not used of course).

It's charging algorithm for Lifepo4 isn't perfect, but works alot better than others.

It also tends to over-report it's solar production by around 10% (reports around 100w more than actual, when supplied with almost 1000w of PV).

But other than that I'm pretty happy with it. I think my quest for searching of the best 24v all-in-one cheap (Chinese? ) inverter is finally over!

I use the second NC contact to turn on a yellow indicator showing local N-G bonding :)

Actually, there is a LOT of discussion lately on Greek social media and YT about this matter and I'm trying to figure out which inverter models can or cannot be "salvaged" using this method

It seems unless the inverter has internally connected neutrals (in-out) this is not possible and bridging them externally is not something I would do unless I know for sure it will not blow up the inverter as some people say it will.. I know on some models this is in fact possible.. anyway

My 4k anenji works nice too although, silent is not one of its traits :) if you exceed 1.5-2kW its clearly noticeable..