Adri76

Do you know how the firmware update works? Is it something I can do or would a supplier/installer need to do it?

I checked the voltages before installation, they were basically the same. If I charge them from eskom to 100% and keep it there for some time they stay in "sync" for a day or 2, but then they go out of "sync" again and after a while the difference will get so big that the bottom battery will shut down, while the top one still have 40% left.

Yes, same age, same supplier, installed at the same time. I have also double checked the connections between the batteries. I was under the impression that the purpose of a "master" - "slave" battery configuration with the communication between the batteries and the inverter would prevent this.

I have a Sunsynk 5kw inverter with 2 x Greenrich U-P5000 batteries. The system is working fine, but every few weeks I have to manually charge the batteries from grid to full and keep them there for a few days to balance the batteries as they go out of balance when used normally. The connections, settings and comms between the batteries and the inverter all seems fine. Has anybody experienced this? (The bottom battery only has 1 led lit on the power indicator, it is off in the pic, because it was blinking)

I have the same situation and would just like to confirm: I understand that the neutrals need to be separate and that the N/E bonding needs to happen when there is no grid (via relay/contactor), but my house has a N/E bond where the cables come into the house, so bonding Neutral to Earth when there is no grid connection will indirectly connect the inverter Neutral to the Grid neutral as they are bonded. Would this be an issue?

Just one more question: There is a N/E bond outside my house in the box where the cable enters the house. Do I use a common neutral/earth from there for my essential loads on the inverter output side, or should I still keep the neutral on the essential loads separate from the main house neutrals and use a contactor for N/E bond?

I have gone through all the Sunsynk manuals I could find, and cannot find any reference to the max AC current the inverter could theoretically draw. (inverter/bypass/charging combined)

With shielded cable I guess it would not be a problem, but I suspect with unshielded cable the EMF might be a problem.

Yes, I think that would be best. I don't want to do the work and have to redo anything come inspection time. I want to use a 35A breaker as that is the max passthrough current of the inverter and 10mm2, but I will see what the elec. says.

I think maybe there is a misunderstanding with the question, I actually wanted to know if it is permissible to have the cables going to the inverter from the DB and the ones going back to the DB in the same conduit. (I'm not even sure it would be possible to get 4 x 16mm and a 10mm in the same conduit)

It has to go in the ceiling, but I have decided to get a qualified electrician to spec and supervise the project so that I will be able to get a COC and not have any problems. Thanks everyone for your input.

I am thinking of using 32mm conduit, but I am not sure if it is allowed.

Thanks Sakkie, that makes a lot of sense. I think the only confusing part is the labelling of the locally available cable. If you look online you will get some suppliers listing their cable in mm2 and some just mm. I have double checked now and the length of the cable run would probably be closer to 15-20m. I have to run cable both ways. (to and from the main DB) Would I have to put each direction in it's own conduit or is it allowable to have both in one conduit?

I think part of the problem is that the SANS regulations I am reading are using mm2 when stating cable sizes and I am talikng about diameter. Is the 16mm cable you are recommending 16mm2 or 16mm diameter? 16mm2 is 4.5mm diameter.

This is still a bit confusing. If I use a wire size calculator (I've tried a few) and enter 220v, 50A load over 30m with 3% voltage drop I get a recommended wire size of 6 awg or 4mm diameter. Are these online calculators wrong or am I missing something?

Hi I am busy installing a 5kw Sunsynk inverter about 30m from my main house DB and I am not sure about the regulations regarding wiring to and from the inverter. According to my calculations 5kw at 220v would draw max 23A. Would it be allowable and would it be legal to use 6mm twin and earth rated at 43.6A for the wiring to and from the inverter from my main DB?

It seems that my inverter has R232 port via RJ45 port. I will try the RS232<->TTL.

Hi I'm also looking into using an ESP32 to communicate with the inverter from Homeassistant. Do you know if all the Axpert type inverters have a RS232 port or UART. Is it not possible to connect the ESP32 directly to the RJ45 port?

Checked everything and the voltage at the batteries is the same as at the inverter under load. My max draw is about 150w and usual draw is about 80w. I know it is a difficult question, but with a 24v lead acid bank of 105ah, what would a good lvd point be to use max solar and keep the amount of cycles I can get out of the batteries as high as possible

Thanks I will do that. I should probably also measure the voltage under load at the battery as well as the connections to the inverter.

I've had some problems with my inverter and have bought a new one. (Axpert type 3000va) My batteries have been standing disconnected for about 3 weeks at +-25.4V (24v bank so almost 100%) Last night I connected the new inverter to the batteries an it went to 27v float within a few minutes. I disconnected the utility power to drain the batteries a bit to get it to start a charge cycle with a load of 120w. The batteries reached the 24v low voltage disconnect within 5min. I reconnected the utility power and it did start a charge cycle which lasted probably 2hrs. Could the batteries have been damaged by being disconnected for about 3 weeks? Surely it should last much longer than a few minutes and charge for much longer if drawn to 24v. The batteries are about 2 months old.

Thanks, I thought that maybe I could just use the scc, but at the moment the battery voltage is 25.6v and the inverter shut down completely. I restarted it and the battery voltage shows as 20.1v, so my only option it seems is the modify the hardware. I'm not sure that it would work as the voltage is sometimes too high and sometimes too low.

Do you know if the displayed voltage is used for everything except scc? ie: Low voltage disconnect, grid charging, back to grid, load disconnect etc.

That is good to know, so it should technically not overcharge the batteries even if the voltage on the display is wrong? I will connect the solar tomorrow and check what happens.

On Instructables there's a mppt charge controller with arduino as the "brain", it might help.