shifttymike

One thing I can think of, is to be aware of the power out being 5000VA, and 4000W. ie. it's not a 5kW output, but a 4kW output per inverter. To compare the cost accurately, you have to pitch it against a 12kW single-phase hybrid.
Just browsing the Powerforum store, you can get the Solis 12kW for just under R35000, and then if you shop around the Deye and Sunsynk 12kW are around R40,000 give or take depending on where you shop.
There's the usual benefits of redundancy with the Victron setup, versus the simplicity and possible installation cost savings of a single 12kW. But I don't think that it's a no-brainer on the inverter cost alone.

Looking at the diagram above, check with a multi-meter set to Ohm's between N on the "Wall Plug" and N on the "inverter O/P".
There should be 0 Ohm's, if not the diagram is missing connections.
The way it's wired, the lights will Always work through the inverter, as there is no changeover. Live from the inverter O/P is wired permanently to the lights.
Your electrician should wire in a bypass switch in case the inverter fails.
On the solar side, what size panel can you connect?
 

I did notice that, and the seller actually contacted me and said that he can't sell me that combo due to this. But from the battery datasheet:
• Compatible with most UPS & Inverters using AGM/VRLA charge setting
• Easy drop in replacement for old lead acid battery installs
• Perfect replacement Lithium solution for upgrading your lead acid installation
He contacted Hubble and they said that it should work, although he won't guarantee it. I'm willing to take my chances.

Yes yes, I know I must be about the 100th person in this scenario
I studied electronic engineering, so I have some background as well as some ambitious expectations. They say someone who knows a little is much more dangerous than someone who knows nothing at all
I have bought myself a 850VA/680W Homaya inverter (Schneider Electric) along with the infamous Hubble S-100 100ah 12V LiFePO4 battery. There were a couple of reasons I went for that particular inverter:
Reputable brand name (SE) Pure sine wave 800W solar charger (12V panels only, a bit meh) 12V 20A output for DC equipment (adds an additional 240w to your power budget, batteries permitting) The use case is:
Alarm: 12V, no idea of consumption Electric fence: 12V, no idea of consumption CCTV (future install): 220V, should be fairly light Internet (ONT + router + 2 wifi APs): 12V for ONT+router, 220V for APs (they need 24V minimum for PoE) My office (laptop, screen, amplifier): 200VA peak when laptop running off charger, closer to 80VA if not House lights: 220V, about 250W peak If I run to 60% DoD on the battery, that means about 350W continuous load over 2 and a bit hours of load shedding. I suspect this should be pretty doable. The house lights will only draw power when I'm not working, they won't all be on at once, and the fact that I can run a bunch of stuff directly off 12V is a huge win for efficiency. Nothing is particularly high power and I mainly want to not be inconvenienced when load shedding happens. Later, I want to add at least 2x 160W panels, probably 4 in total which will limit the drain on the battery and start saving me some electricity. When I win the Lotto, then I will start looking at a separate, bigger system to keep more stuff on and limit my Eskom bill.
If I need to drop the consumption, I could throw some 7ah batteries at the alarm, CCTV and electric fence and leave them off this system. The fence is the only one I'm worried about as the power draw is probably quite significant once it actually starts shocking. The others are probably fine to stay on.
Yes, I know I'm a little crazy but I'm going to push the limits of what I can get out of a small system like this. I think that not having a desktop PC and running a bunch of stuff directly off 12V means that this might just be crazy enough to work...
That's me, in the context of this forum  I'll be around asking silly questions.