FixAMess

Do you mean the GW5048D-ES? Yes it is NRS-097 certified. Just search for "NRS 097 Approved inverter list" and the CT list will pop up with a table of approved inverters with their report number and certificate number.

Also remember that it's not ideal to keep a battery at 100% . 
So charge the battery, let the cells equalise and then discharge to 90 - 95% SoC.

Just a thought. I was at a small factory complex and saw a trolley, on wheels that held 3 panels. They pushed the panels out of the shop into the sun in the morning and pushed back into the garage at night. Rather clever, I thought.
You will need a decent voltage to test, depending on MPPT specs, so you might have to connect panels in series/parallel to test but 3 panels should cover most MPPTs..
 

Just a thought. I was at a small factory complex and saw a trolley, on wheels that held 3 panels. They pushed the panels out of the shop into the sun in the morning and pushed back into the garage at night. Rather clever, I thought.
You will need a decent voltage to test, depending on MPPT specs, so you might have to connect panels in series/parallel to test but 3 panels should cover most MPPTs..
 

How many panels per A-frame?
I read the design specs for my flat roof, they specifically mention a weight limit per SQM.
Can you imagine the fuss the insurance company would make if they did their sums and found out the roof structure was not designed to take the additional ballast + panel weight.

I'd stipulate additional insurance be taken out to cover the adjacent buildings in case of fire etc..This can be restricted to fire caused by panels only, will save underwriting costs.
As for annual maintenance: Does an annual maintenance schedule even exist, who will contract for an annual checkup? Just stipulate an annual checkup must be done at anniversary of install.
Too many mentions of "high quality"..Either define "high quality" or stipulate equipment specs. 
 
 

I'd stipulate additional insurance be taken out to cover the adjacent buildings in case of fire etc..This can be restricted to fire caused by panels only, will save underwriting costs.
As for annual maintenance: Does an annual maintenance schedule even exist, who will contract for an annual checkup? Just stipulate an annual checkup must be done at anniversary of install.
Too many mentions of "high quality"..Either define "high quality" or stipulate equipment specs. 
 
 

I'm an owner, not a seller. Are you saying that it is possible to parallel these units, or that it's possible after a certain revision?

Might be a good idea to get accurate cycle, soh for US3000B's and C's...Then people will know exactly what they are getting.
E.g B's about 600 cycles.

It's the BMS that's the issue, some only speak specific protocols which the inverter may not speak.
The market has certainly changed over the last 3 years, even the last 12 months. Battery prices have dropped substantially,  there are many brands and choices. 
Even the inverter market has grow, many new entrants, options.
Frankly, in 5 yrs time the equipment one buys today will be outdated and you will battle to find batteries, inverters and panels that are compatible with it.
High voltage, inverters/ batteries will become the norm.....Watch this space.

Every year for 3 years in a row, we had our PC equipment, printers, routers "burnt" by lightning...Everything connected to the telephone lines was blown. It turns out our neighbour had replaced the old Telkom wooden pole with a magnificent steel one, nicely painted silver and shining.
Since I've disconnected the telephone lines no more problems...

Every year for 3 years in a row, we had our PC equipment, printers, routers "burnt" by lightning...Everything connected to the telephone lines was blown. It turns out our neighbour had replaced the old Telkom wooden pole with a magnificent steel one, nicely painted silver and shining.
Since I've disconnected the telephone lines no more problems...

I swapped out a lightning damaged Goowe for a working, used one a few weeks ago. I had to get support to change the "owner"/ installer of the used one so the new owner could access it.
1 phone call and it was done! I was rather surprised.
They're reliable inverters, mine is 5 this year, no issues,never skipped a beat. I'm hoping another 5 yrs to go.

Here is a interesting read about Parallel of lifep04.
https://www.master-instruments.com.au/tech-talk-article/3/Explaining the limits of LiFePO4 batteries in parallel.html#:~:text=First%2C we need to understand,is unlikely to be equal.

I swapped out a lightning damaged Goowe for a working, used one a few weeks ago. I had to get support to change the "owner"/ installer of the used one so the new owner could access it.
1 phone call and it was done! I was rather surprised.
They're reliable inverters, mine is 5 this year, no issues,never skipped a beat. I'm hoping another 5 yrs to go.

I just went through this exercise...Remove panels, paint 2 coats, reinstall...
It took me and 2 others 1hr to remove 8 panels.
Prepare for paint, paint, dry, 2nd coat..
Reinstall panels, also took 1 hr.
Sad thing is I found where the installer had taken shortcuts on connecting the rails. There is a small connector that slides into the end of the rail to connect them. He did not use them and I could not see when inspecting because they were covered by panels.
Lesson....Inspect each phase of the install.
Roof
1) Placement of brackets to rafters/beams...Make sure tiles are in tact and repositioned correctly. Also correct spacing and insertion of brackets
2) Make sure rails are installed correctly, all joins dealt with
3) Panels are installed correctly, wiring tidy and placed in conduit if that i what you required.
 

Here is a very nice explanation of "global" vs "local" MPPT tracking....
https://aurorasolar.com/blog/the-importance-of-modeling-global-maximum-power-point-tracking/

Where areas are prone to lighting strikes( Drakensberg) i use ABB Class 5 surge arrestors on the AC side. Below example of the ABB. Short Circuit breaking capacity 100KA.
https://www.online.elio.co.za/product/ovr-t2-t3-1n-20-275-p-qs/?utm_source=Google+Shopping&utm_medium=cpc&utm_campaign=GoogleFeed&gclid=CjwKCAiAvdCrBhBREiwAX6-6Use5-N0KYXkDEOON5971CuwZvaF6aJkGcq0y0OMHGKByeKHwA9n9YxoCjy0QAvD_BwE
 

Are you sure it's Goodwe pushing firmware upgrades? I have a Goodwe and they CAN update it remotely, but don't unless I ask them.
Could it be some setting that is telling the inverter to check for new firmware? 

Instead of just using a spreadsheet it helps to understand how/why the calc is required/done.
Here is a write up for the OP to figure it all out...Can't remember where I got it from and cant take credit for it.
As temp decreases, panel Voltage(V) increases. We want to calculate the maximum Voc for a panel at the minimum temp we expect in the region. So for JHB we use 0’C, in Bloemfontein we use -10C or whatever you chose...
To calculate string length (series) use the total Voc (Sum of voltages, because they are in series remember, (+) including adjustment for cold temp) from panel data sheet and then do as follows;
 Record-low temperature: -10ºC (From your region, town)
Temperature coefficient of (VOC): – (0.30) %/ºC (From data sheet *)
Module open circuit voltage (VOC): 39.4 V *
Inverter maximum input voltage: 600V (From inverter, MPPT data sheet)
The STC temperature is 25ºC. This temperature needs to be deducted from the array location’s record-low temperature of -10 degrees as follows:
25 – (-10) = 35º difference.
Multiply the 35º difference by the temperature coefficient of VOC (I’ve used the positive value for an easier calculation, though you get the same result) then multiply by the module’s VOC:
35 x 0.0030 = 0.105
0.105 x 39.4V = 4.137V (So the Voc will increase by 4.13 V if the temp goes down to -10C)
This is how many volts each pv module will increase due to record-low temperatures.
Add the voltage increase to the Module VOC.
Then divide the inverter maximum input voltage by that number. This will give you the maximum number of modules that can be wired in a series string per that inverter and specific location.
4.137 V (from calculation due to low max low temperature) + 39.4V (from datasheet) = 43.537 Vmax (At -10C) Increase in voltage due to temp drop per panel.
Normal voltage at 25C
600V / 43.537 = 13.7 Panels (round down to a whole number)
The maximum number of pv modules in this series string is 13.
A series string of 14 could potentially produce more than 600V during record-low temperatures.
When string in parallel, add Current, V stays the same, when in series, add Voltage, I stays the same.
 

Question; How does one know when your battery is performing well?
There are so many statements that refer to X is better than Y because it "performs well".
Pylontech "performed well" till we got 3-4 yrs experience in using them....and the warranty sems to be worthless
China, where most batteries are manufactured grades their batteries industry wide as follows;
"A" grade ; "A + " and "A-"  (A+ have 2 yr warranty with manufacturer, A- the reseller/battery manufacturer carries the warranty)
B, C etc...
So any A-grade battery cell should be of the same quality on a cell level.
How many people have actually taken their battery apart to see what it looks like inside, see build quality?
For me there are 2 major decision criteria
1) BMS - One should buy a battery based on the BMS it uses - if the manufacturer does not tell you the make of the BMS stay away.
2) There must be a BMS application that you can use to see what's going on in at a cell level 
3) Does the battery talk to the inverter without fancy additional cables, configs, fine tuning etc.
4) Warranty - Does the manufacturer / supplier keep to their word?
5) PRICE..
So based on the above, any A-grade battery with a decent BMS (PACE comes to mind)  will do the job and provide "good performance".
My view;  Price, make sure the cells are A-grade, battery has a decent BMS.
Also, most manufactures will say "1C", but in the fine print they recommend C/2 charge and discharge.
Its purely a physical chemistry thing that the charge rate over C/2 degrades the battery quicker due to lithium plating on the anode.
I have pylontechs, frankly I don't expect them to last 10 yrs. I also expect that in 10 yrs time there will be different Tecnologies that will make our current batteries obsolete.
 
 
 
 
 
 
 

Question; How does one know when your battery is performing well?
There are so many statements that refer to X is better than Y because it "performs well".
Pylontech "performed well" till we got 3-4 yrs experience in using them....and the warranty sems to be worthless
China, where most batteries are manufactured grades their batteries industry wide as follows;
"A" grade ; "A + " and "A-"  (A+ have 2 yr warranty with manufacturer, A- the reseller/battery manufacturer carries the warranty)
B, C etc...
So any A-grade battery cell should be of the same quality on a cell level.
How many people have actually taken their battery apart to see what it looks like inside, see build quality?
For me there are 2 major decision criteria
1) BMS - One should buy a battery based on the BMS it uses - if the manufacturer does not tell you the make of the BMS stay away.
2) There must be a BMS application that you can use to see what's going on in at a cell level 
3) Does the battery talk to the inverter without fancy additional cables, configs, fine tuning etc.
4) Warranty - Does the manufacturer / supplier keep to their word?
5) PRICE..
So based on the above, any A-grade battery with a decent BMS (PACE comes to mind)  will do the job and provide "good performance".
My view;  Price, make sure the cells are A-grade, battery has a decent BMS.
Also, most manufactures will say "1C", but in the fine print they recommend C/2 charge and discharge.
Its purely a physical chemistry thing that the charge rate over C/2 degrades the battery quicker due to lithium plating on the anode.
I have pylontechs, frankly I don't expect them to last 10 yrs. I also expect that in 10 yrs time there will be different Tecnologies that will make our current batteries obsolete.
 
 
 
 
 
 
 

Am I missing something? How did you come up with that price? 
 
If one looks at the individual prices of the above as brand new items:
1x Pylontech US3000A - R21000
1x Pylontech US3000 3 bay cabinet - R3350
1x Pylontech UP5000 - R26000
1x Pylontech UP5000 3 bay cabinet - R4300
2 x Pylontech battery cable kits(2m) - R1140
 
Total R55790 - Brand new. 
 
 

If you have not already, you should update the firmware on the US2000 to the latest version.
PM me if you require the .bin file.
 

It will not effectively balance the packs no. As an example say you have a new battery which comes at 50% SOC and parallel that to a 80% SOC battery , they wont balance fully as there is not a big enough voltage difference for current to flow. You want to balance packs the same way you would when balancing the cells inside a pack and that is by charging them up to 3,55V-3,65V a cell.