Frost

Hi. Please send me your inverter serial number and logger number and I’ll check for you and request an upgrade. 

Look at the graph of PV amps, if you have a constant load and clipping, the normally round curve will have a flat top instead.

Put a constant load on it, observe the amps.
Some of the older Sunsynk 8K inverter MPPTs are 22A capable after a firmware upgrade, I have seen Sunsynk support confirm it on the Whatsapp support group, they first need to check the side sticker though.  

Installation completed. 

Busy with a 3 phase installation with 3 x 5kw Sunsynk and 3 Hubble’s. 
 
Will post pictures when it’s complete. 

Correct

Batteries will always get charged first, unless there are loads and "priority loads" is ticked. If batteries are full, then the inverter does not "waste" the excess, it will only draw whatever it needs, so if loads are at 600W, it will draw 600W (or slightly more to compensate for inefficiency). Agreed that technically it is wasted "potential", but as discussed before this potential can be directed to a smart load, like your geyser. The Sunsynk Super Hybrid is very flexible. 
If the panels generate more than 5.5Kw then you will have one of two problems: 1) either the voltage will exceed the 500V max limit, in which case it will probably blow the MPPT (volts are very important in array sizing), or 2) the amperage will exceed the specs and the MPPT will clip it. This is wasted potential. The 5.5K Sunsynk is (anecdotally) known to clip at 9.9A even though the specs state 11A and maximum DC input power is stated at 6500W. See the Sunsynk tech forum thread here.  

I don't know, but 90A@220V=app 19kW and 70A@220V=app 15kW, either way, your EL/CB is probably only rated @63A, I guess, so why worry, else its time to upgrade to 3phase X 40A each and be done with it...

a colleague has the 5 kW Sunsynk and has the high pitched noise issue, can even hear it iemanating from his clothing iron, has not figured it out yet, the family has sort of gotten used to it

There are 3 connections on the inverter. 
Grid connection. This is the grid input connection but is also an output if the grid is available. If there are loads after the municipal meter but before the inverter, these loads can be supplied by the inverter from either solar or batteries up to a maximum of 8kw
Load or UPS connection. This is the primary load connection for what you want to power in the event of grid failure. The loads that can be supplied from either solar or batteries is limited to 8kw. If your loads on this connection exceed 8kw, the inverter will pull the difference from the grid if its available. The maximum pass through from the grid is 90A. As an example, if your loads are 12kw on this connection, the inverter will draw 8kw from solar or batteries if available and the balance of 4kw from the grid. Pass through value is what the inverter will pull from the grid for loads supplied by the inverter that is more than the available DC battery or solar availability. 
Aux connection. This is a configurable input or output connection. If its used as a secondary output, the same pass through principle is applied. Total pass through of 90A is shared between these two connections. 
If the grid is down the inverter can still invert up to 16kw for 10 seconds from available DC sources. 
I do think they assume that the installer or electrician would be aware of what these terms are as they do state pass through limit on the specifications and they would explain these to the homeowner. 

1. The 8kw inverter should be fine. I have a solar evacuated tube geyser and 3 aircons running from the inverter. 
2. Correct. It will pull what it needs from the grid. 
3. I get about 80% from my panels but in summer this increases to 90%. Currently have 8.54kwp of panels and adding another 1.83kwp on Sunday. 
4. This is possible using the aux as a smart load output. 
5. Can't comment here. 
My average pv production from 8.54kw of panels is 45kWh per day. 

I have my 2 kW geyser connected to the Smart Load output, set the solar threshold to 2200 watts and battery to 100% ON and 95% OFF, works great, and there is cloud cover i switch on "Always On Grid "

There are pro's and cons. I do like the idea of two inverters, but I didn't want the additional expense. But if you can do it, definitely.
It will max out at 8.8 kW with all sources blended. I am in the same situation, two houses (cottage for my parents). The 8 kW Sunsynk if more than adequate to run our loads. The one remaining electric geyer runs on a timer on solar and it works fine. On cloudy days the inverter blends Eskom with the solar.
As long as the Voc on the solar strings don't exceed the interter rating it should be fine. Current will be clipped if it exceeds the inverter rating. We only have 4.5 kW of panels, and thats perfect for clear days, but we do fall short on partly cloudy days. My next upgrade will be another few panels. I think with more than 10 kW you should be good to go.
The solar system only produces as much as the load you can put on it. So if the batteries are full and you don't have load, the energy goes to waste. Also, the batteries will charge at their max rate, in the case of my Dyness I am limited to 7 kW on the four batteries.
 
You can do that, or in my case I just used a CBI Astute wifi timer to time the geyers.
It is probably better to run it on the Aux output so the inverter can power down the geysers if your charge gets too low on a cloudy day. However, the Inverter will keep Aux load on while the battery has sufficient charge, so I still suggest adding a timer. You do not want the electric geysers to ever take charge from the battery. The same with the oven. I have limited the battery discharge in the evening so when the oven is in use a little bit of battery is blended with Eskom to feed the oven. The oven is on the grid side, so if Eskom fails, the oven stops working.
 
The above is my work in progress. More panels are in the works, from 4.5 kW to 6.9 kW, and perhaps one more battery, 14.4 kW to 18 kW, then I think my system will be sufficient for my needs.

I still need Eskom during the low pv days until I can add more batteries. 
Not sure how the parallel setup will work. Maybe @Vassencan comment as he has the 5kw sunsynk and planning on adding another one in parallel. He might nave done more research on it than me. 

Every installer I've found know very little about the capabilities of the sunsynk. I decided to find a sparky and told him how I wanted the unit installed and basically project managed him during the install. It's a hybrid so it will blend from the grid even if you go over the 8kw of the inverter. I have witnessed this first hand with screenshots in another thread. 
It still produces pv on cloudy it rainy days but very little. The lowest I think was the about 12kwh. 
Current month daily PV generation for Somerset West, Cape Town. 

Tells you that a lot of installers don't know what they are talking about, just the other day I was doing 7.52 kW's on a 5 kW Sunsynk, the 5 kW was coming from the inverter and the balance of 2.52 kW was being supplemented by the grid, and it probably was an easy 30 plus minutes, till the geyser and tumble dryer shut off

2. It can pull continuously as long as you need it to. No time limit. 
3. Yes in adding 6 more of the same panels. 
4. So the sunsynk has two out puts. The first one is ups load output. This is your essential loads. The second output is the aux and can be configured to run loads when there are excess solar available. You can also configure it to run from batteries so you can still power these loads during load shedding if you want. 
The grid input is also and output and your non essential loads could be before the inverter. The inverter can then send power back through the grid connection to these loads. When there is load shedding however, these loads before the inverter will never receive power from the inverter or batteries. 
Current total PV generation since the system went live.