JK844

Running my house off grid, by that I mean I have a change over to Eskom if really needed, but my Inverter is off grid, i.e. no grid connection there.
It runs 5kW no problem, will even sustain up to 5,5kW but I manage all high power items sequentially. i.e. when the Geyser is on I don't run the Dishwasher or Washing Machine. Mostly runs between 3 and 5 kW when high loads are required for short periods.
Took about a year for the others in the household to eventually realise to check first between 10 and 12 if they can switch on the other high powered stuff. My Geyserwise is set to start at 10. Geyser never takes more than 1 to 1:30 to get to max temp.
The whole house runs off the 5kW, just not at the same time. Sequential management and it can be done easily. 
Have a stove top with two electric and two gas. In the daytime the electric elements are used (it's free solar) and the gas is used in the evenings or when the solar is minimal. Saves on the gas too.

 

@Dylboy @BritishRacingGreen
Thank you both for your replies. I'm going to do both probably. I'll run a 6mm earth cable with the PV cables and earth the panels to the PV DB which is earthed to main DB. Then I'll run a 6mm cable to an earth spike. Sparky shouldn't fault that. 

I was told minimum 4mm square wire over short distances and recommended was 6mm square.
 

Exactly. The higher the voltage the thinner the cable can be. 8 x 550W panels in series can even use 2.5mm2 cable. 4mm is plenty 

It has Bosal connectors, couplers & 90° bends designed for cables exactly the same as the PVC conduit. No bender required. You cut it with a hacksaw. It's actually just hard to work with as it gets sharp edges & gloves are a very good idea. 

Wires need to be correctly sized for the current and voltages used in your system.
You did not mention this information in your post making it difficult to answer.
In any event, I do not see many scenarios where the 1mm2 cable will be sufficient. 
Also remember that PV cables are moisture, sunlight, and flame-resistant and behave extremely well in very hot temperatures. 
Undersized cables are a major fire risk.

I have a 5kVA off-grid inverter, and I have it running my whole house except the geyser and stove.
i.e. All plug and light circuits
 

I also run my whole house off a single 5kW inverter:
Borehole pump Swimming pool motor Oven & hob Geyser element Kettle Wall plugs Lights Panel heaters etc. Some of them are very high draw items (I'm looking at you, you 3kW oven!) and you may need to ensure that you do not run them at the same time as other high draw items (kettle or geyser element).
It also pays to spread the load...  Our home's base load is around 500 W (3x fridges/freezers, extensive alarm system, three desktop computers, fish tank, etc).  Every morning at 08:30 our automated sprinklers turn the borehole pump on (1.3kW) for 30 minutes.  When they're done at 09:00 the pool motor starts up (750W) and runs until 17:00.  If it's very cloudy the solar geyser's element (2kW) may kick in at 13:00 via a GeyserWise megafter to ensure that the water temperature is at least 65 deg C.  If my wife were to boil a kettle (another 2kW) during this time, my home automation (Nodered & Sonoff) would turn the pool pump off to ensure I stay below 5kW.
If you buy a grid-tied inverter like mine you can get away with peaks over its rated output (it will just supplement the difference from the grid), but I try to remain off-grid as far as possible.
Oh, and I agree that it won't hurt to chat to Paul at FCS when shopping for inverters!

I mean they'll say the kW, for all the newer Axperts, 5kVA = 5kW.  But that said, the power factor does not come into play on the inverter...  Power factor is determined by the devices you power in your home.  So ultimately if you bought good quality stuff your PF is close to unity (1.0) in which case the extra power factor overhead is wasted.  But if you use a lot of things like florescent lamps, motors, very old switch mode power supply, your PF could be around 0.5 or lower in which case having an inverter with a higher kVA rating is sufficient.
That said, if the kVA and kW on an inverter doesn't match, I don't put much faith in it.
EDIT: My point was power factor is not an indication of quality of the inverter.  But I wouldn't buy an inverter based on kVA rating, you look at the KW and decide based on that.  The kVA is just gravy on top.

I live in an apartment, so I don't use the solar charge controller.  I just use it as backup when Eskom fails.
My light circuit and a "red plugs" in ever room of the apartment are fed from the inverter.  Been running like that since roughly 2014, I switched to an Axpert King in 2018 (If I recall correctly) for the double conversion, I have a lot of computers and stuff I didn't want damaged by Eskom's sh!tty supply.
I power my TV, router, microwave, kettle, Nespresso, fridge, TV, amplifier for TV, NAS, home office from the Axpert, occasionally things like vacuum if there is load shedding and the place needs cleaning.
The Axpert King runs in inverter mode 24/7 and it has held up well, when I turn on the kettle or microwave the fan speed increases but it is pretty much drowned out by the noise those appliances makes.  Everything else it remains fairly quiet (so not much load).  I rarely go above 3.5kW.
Different brands may have different models.  You can look at the models available here: http://voltronicpower.com/
Voltronic Power makes the actual inverter and then puts the badge on the seller wants.  There are companies that manufacture clone Axpert inverters, meaning they actually copied the design.  They took an already low cost inverter and went cheap on it, so you can guess the end result of that.
My 2c: Buy your inverter here https://www.fullcirclesolar.co.za/
I've bought a few from them, they are the cheapest I could find, respond quickly and they don't sell fakes.