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My second stab at this.


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So my hybrid system has been running pretty smoothly for the last four years, but as expected, the batteries are now starting to fail on me, mainly due to heat, somewhat due to a bit of partial charging, and the odd very deep discharge.

Rather than just replace the bank and carry on for the next four years, I figured, I'd change things up slightly.

Currently the system runs the house apart from the geyser and stove (which are solar and gas respectively), but that does mean it's had to cope with oven, microwave, and the occasional aircon loads.

I'm planning on a bit of a downsize, but how much of a downsize is what I'm still deciding.

It will be running all of the lights, that's a non negotiable (from the wife), which also means ceiling fans, but I can live with that.

It will be running all the plugs to which we have our entertainment connected (TV, internet, computers). Luckily for me, these are all on one breaker in the house DB board.

I'd also like it to power the pump for the water tank, but that would require quite a lot of fiddling. Worst case, I run an extension cable if we're without water and power at the same time.


The one thing, I'll be doing in this exercise is selling off the second Axpert MKS, since it was only there to cater for when we used over 4kW. Obviously, I'll be recycling the 8x 200Ah batteries.

I'll also be moving the setup from the garage, into a little unused nook behind the house DB board. Should be a perfect fit the for the remaining Axpert, and a couple of Pylontech US3000B batteries in a cabinet.

I like the fact that this little area is directly behind the main DB as I'll be able to wire in a second DB for the inverter, split off the loads I want to split, and installation/recertification costs should be manageable.

As before, I'll try do as much of the install as possible leaving only the rewiring of the DB and cert to someone way more qualified than I.

Pics will be posted as I progress, and I'm quite looking forward to this second stab at things, taking into account all that I learnt (both good and bad) from my first attempt.

Now, to source the batteries and cabinet.




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I don’t know how much load your aircons will draw (mine need a service and it is the one thing I have no idea what the load will be, we are not using it that much).

I would definitely, to increase the life of the batteries, also move the oven over to the grid directly. We have about 4x roof fans running through the night, they are not making much of a difference in our night time load. 
The microwave is so quickly, don’t think it should be an issue. 

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Batteries and Cabinet arrived on Tuesday afternoon.

Had a bit of a hiccup with the cabinet missing all of the fixing hardware, so that was only put together on Wednesday, and today I mounted the inverter on the wall.

Connected up the batteries directly to make sure everything is working (Fuses, disconnects, etc will be installed in due course), setup the inverter as per the Pylontech instructions, and am happy.

Not much going to happen until next year, when I get the electrician in to rewire the DB board and install the new DB board back to back.




@Wilfred Mine is a very old AC, and uses 3kW IIRC, so we hardly have it on. It will stay on the grid only circuit though, along with the oven, and geysers.

Edited by viceroy
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  • 3 weeks later...

So, we're into the new year (Happy New Years all), and I want to get my system going pretty soon.

In terms of progress from last time, I've not done much. I've installed a new manual disconnect for the PV. I'll soon be adding some protection to that, lightning and what-not.

I was planning on getting in an electrician to rewire the DB, drill through walls, etc, but I'm finding that since this is all in the house, it must look decent, everything must be straight, and I don't trust anyone but myself to get it just right.

I'm very happy to do the work, except for drilling through walls, but I'm no electrician, so have no idea if my work will be correct, and whether I'll be able to get a CoC without having to pay out for my mistakes.


What I want to do is run all the lights, and either 1 or 2 plugs through the Inverter, the rest must stay on grid only.

I also want to be able to be able to manually put everything on grid.

Does anyone have a diagram (photos would also be good) of how to do this correctly?

I really do want to take a stab at this, but I also want it done correctly, and neatly, and not cost an absolute fortune to do. Was quoted a little over R5000 for an electrician to do this, and the only thing stopping me is How neat and tidy it will all look once done.

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I did some slight rework on my DB board. Replaced (DIN clip was broken) and moved the second geyser to sit next to the primary geyser, and replaced a faulty breaker (broken DIN clip and intermittent connection if moved) for the lights.

I also mapped where each output wire for all the plugs and lights went (Hoping to mix and match a bit to get all desired loads through the inverter.)


I've also wired up the inverter DB board, which now includes a bypass switch, which I didn't have before.



I've pretty much decided how I'm going to wire everything, but one question remains... Can I drill out through the back of the main DB board, through the wall, to where the Inverter DB board will sit, or do I need to exit out the side and then drill through the wall to get to the other side? All needs to be CoC compliant, which is why I ask.

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14 minutes ago, viceroy said:



Excuse me for being "that guy", but I have one concern about this.  The top of the Clipsal breaker is daisy-chained across to 7 other breakers. If you add up the current of those breakers, there you have a 120A. The input side is protected by a 63A breaker though, so that is the maximum here. That means your daisy-chain "loops" across at least the first four breakers must be capable of 63A. They look a bit thin to me...

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1 minute ago, plonkster said:

Excuse me for being "that guy", but I have one concern about this.  The top of the Clipsal breaker is daisy-chained across to 7 other breakers. If you add up the current of those breakers, there you have a 120A. The input side is protected by a 63A breaker though, so that is the maximum here. That means your daisy-chain "loops" across at least the first four breakers must be capable of 63A. They look a bit thin to me...

Funnily enough, I was saying almost the exact same thing to my wife, when I opened up the DB board, and how could the electrician have supplied a CoC when we did the renovation 7 years ago.

There are quite a few things that are just plain wrong in there, which I do plan on fixing, when I actually get properly going on this, but for the time being...just need to know the correct way to break out of the DB to supply the inverter DB on the other side of the wall.

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18 hours ago, Shockin said:

May i ask why are you moving the system from the garage to the house?

Mainly because the average temps in the garage are around 30 - 45C season dependent, a real battery killer, while the house hovers around 25-30C in summer.

The main DB board is also in the house (in a room that used to be garage, until we renovated, and built a new garage), so much easier to split the loads between essential and non-essential.
How I had the system before, was the WHOLE DB ran through the inverter and batteries, which is obviously not ideal.

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18 hours ago, Shockin said:

Replace all those links with a copper busbar,  move your essential load cbs to the right of your db board , drill thru the wall

Thanks for also confirming the drilling through wall.

Moving the non essential loads to the right of the board is my plan, and I did that part already.


Now new question. Can I keep the neutral common throughout the whole system, or do I need to split the neutral between the non-essential and essential loads? Please see crude diagrams for what my rather uneducated self was considering. I'm assuming, Earth can remain common throughout the whole system.



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1 minute ago, Shockin said:

You need to split the neutrals as well

SANS allows a shared neutral in a few cases: If the "standby power" feeds in "at main supply", then you are allowed such things. It's figure S.1 in Annex S of SANS-10124-2-1.


In your case, since you're feeding only a part of the installation, you must split the neutrals.


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Thank you @plonkster, very interesting.

The diagram raises one more question for me though. In my Inverter DB, I have a main breaker before the inverter. Looks like I should add another main breaker (Sub main Switch) after the EL?

Can that sub main switch be housed in the inverter DB or must it sit in the main DB before the essential loads breakers? If it needs to be housed in the main DB, I'm stuffed as there is no more room :(

Definitely going to need a few more indicator lights and warning labels on both DB boards. ;)


@Shockin Already in place, however, while we're discussing, I have 100A breakers on pos and neg, but a 100A fuse only on pos. This is as the solar installer previously did it. Should I also have a 100A fuse on neg?

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7 minutes ago, Shockin said:

You have breakers and fuses on your battery cables? As far as I know you only need fuses there, fuses will blow quicker than the cb 

Yes, but the fuse is only on positive. I just replicated what the solar installer did previously.

Please excuse the messy cables. All will be shortened and tidied once I have the trunking in place.


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