EugeneS

You are correct, this is the place where to get help or find more info. You are allowed to start as many threads and ask as many questions as you want, some guys will answer. Do not worry about negative responses from people who can't help you, you find such people in all forums. Just ignore them and wait for the answer from the people who actually want to assist. It is strange that people are more worried about you charging your clients or that you are an installer and can't be spoon fed. We are all here to learn and share knowledge, no one knows everything and there is no silly questions 

The unit will mostly work as a alarm system backup, and will be used to power few lights, WiFi and TV during load shedding.

Hey @EugeneS, one of the members here just simply replied that Sunsynk and Narada's BMS don't communicate, meaning you wont see the BMS readings on your inveter but only the SoC. So the settings are uploaded where confirmed to be fine as they are a work around due to the non communication of Sunsynk and Narada batteries.
But after a year everything is working well with the settings as they are. Just need to find a better kettle as it is the only enemy to the solar system for now due to its high power consumption.
Apologies for responding so late and hope my response helps you.
NB: I am not an Expert...😆

Hi All 
I was lucky enough to get one of the new Sunsynk Dongles to test out. 
I am very impressed and it sorts out most of the criticisms of the older Solarman Dongles. 
Thought I would make a post of my impressions on the unit so far, is still in Beta as far as I am aware so I am sure that things will change.
Main  improvements/functionality I have seen so far:
- Much more up to date data being display in app and on the website. There is a setting in the app where you can set the refresh rate for the data from between every 60s to 600s

- Ability to change the inverter settings from either the website or phone app.  Handy for when load shedding is announced and you want to chnage you system mode settings to make sure you have enough battery power in reserve. You are able to change any of the inverter settings from the menu's
- Ethernet port on the dongle for more connectivity options
 
Things that I think could perhaps be improved/changed/added.
- I think that the user interface does not seem to be that intuitive to me from the outset. I would like to see the settings menu's changed to something that more resembles the menu's on the inverter which most of us probably know pretty well already. 
- There is loads of information available, again but not all that intuitive as to how to access everything 
- Would be nice to be able to get data either from the Sunsynk servers or directly from the dongle into our home assistant's directly without having to go through the RS485 port. 
This is obviously all my own personal opinion and am interested to hear what other people who have seen it think of it. 
 

Thanks all, the 9 panels were installed yesterday. All seems good so far. Was overcast when we connected them and reading was at 410v. I have peace of mind with the 9 panels and think I'm still generating more than what I need. 

I have 28 x 455watt JA Solar panels installed on my Sunsynk 12,740W altogether.
2x6 on one string and 2x8 on the other string. Max voltage I have seen on the  longer string is 390V and that is with a probably 25mtr cable run so I would guess I am loosing a few volts there. 
Max Amperage I get is 19.9A on both strings so I am assuming that the inverter is clipping slightly.
My suggestion would be to stay well clear of the max voltage of the MPPT and just split it into two strings and leave some space for more panels when you have some spare cash. 

a friend of mine is using the new Canadian Solar 595 watt panels, Voc is 41.1 vollts and Isc is 18.42 amps on his Sunsynk 8 kW, he is installing 9 on each mppt, so for a total of 10,710 watts which matches the inverter perfectly and you can use one combiner ( protection ) box

OK so here are my calcs using this method:
 
  String size calculations                               JA Solar 540W panel JAM72S30 525-550/MR   8k Sunsynk inverter       VoC 49,600000 volts           Vmp 41,680000 volts           Max panels 10,080645                   Max Voltage 500,00             MPP 125,00 425 volts         Max input DC power 10400,00 watts     Minimum string size 2,999040 therefore    3,00 panels per string minimum     maximum string size that doesn’t exceed operating voltage 8,568548 therefore    10,00 panels per string max     Does max string size fall within MPP range 416,800000 therefore    YES                       Would extreme temperatures cause us to fall outside a safe operating range?                                                Coldest day ever       4 degrees celsius     Temperature Coefficient of Voc       0,275 percent     NOCT       45       Difference       41       VoC * temp coefficient (voltage change /degree celsius)       0,1364       Multiplied by temp difference (what each panel will produce extra on a cold day)       5,5924       What each panel will actually produce on a cold day       55,1924       All panels together 6     331,1544         7     386,3468         8     441,5392         9     496,7316         10     551,924         11     607,1164         12     662,3088       Warmest day ever?       26 degrees celsius   so not over NOCT So yes, it is possible to use 10 per string, but you will run into problems if the temp drops to 4 degrees in Winter. Will it ever be 4 degrees in Kempton Park between 11H00 at 13H00 is anyone's guess, and further research is needed, but note that you start running into problems once you go lower that 43 degrees C already 😀
You could argue that your azimuth (at 20-25 degrees) and pitch is not optimal, and therefore could negate the temp co-efficient, but those are quite complicated calculations to make, and remember that real-time azimuth changes every second because the earth moves and wobbles.
Practically speaking, if I were you, I would go with 9 panels (and leave space for a tenth one) and then monitor the system over 1 year at least before making a decision on the 10th one.

Thanks, will take a look.
Over the specified voltage will result in expensive damage. The MPPT can easily clip the amps, but not the voltage.

I was talking about the panels' model # / specs. 😀 Or maybe you have the spec sheet that you can share?
Azimuth is the direction that your roof (and thus your panel) is facing relative to True North. You can get it to a reasonable degree of accuracy using Google maps.
Azimuth and pitch (or tilt angle) are important to know, because the panel's specs are derived at optimal conditions, and your own installation probably deviates from this. If you know what this  deviation is, then you can more accurately assess the degree at which the panel's performance would be degraded, and those voltages might not be so scarily high after all.
Kempton Park is roughly 26° 6' 0" S / 28° 13' 59" E. As a rule of thumb, optimal pitch is equal to the Latitude, so for your install this will be slightly over 26 degrees (relative to level ground).
Here's a vid explaining it: 
 
Location is also important for historic weather conditions, to size panel arrays you will need the lowest temperature recorded in the past say 10 or 20 years, this is because the panels' specs are derived at STC and / or NOCT, and lower temperatures than these cause the panel to produce more power than the spec sheet. You can get this information from a site like this.   
Once you have all of this info, here is a good guide on how to use it to do string sizing, and to take into account temperature coefficient.

Cloudy day again in Cape Town, see all the spikes, and one spike went right out of spec at 2670 watts.
I have 4 of those 540 watt ja solar.

I have those exact panels. Those panels are supper efficient.
Be careful for partially cloudy days, then they far exceed their max rates at times.
If your recommended max voltage is 500 then I personally would aim for 450max on the safer side.
It's the voltages that makes the smoke

There is a list of Sunsynk approved installers here: https://www.sunsynk.org/approved-installer-1

In order to not go the suicide plug route. 

Hi Eugene. 
 
One thing to remember is that Pylontech will not honour a warranty when you pair 1 x 3.5kwh Pylontech with an 8kw or 5kw inverter. Reason is due to the massive return on failed batteries which forced them to change their warranty requirements. 

Do people on here provide recommendations for installers or is that frowned upon? I'm thinking that I should likely get an installer to assist me.