JustinSchoeman

1)

3) Fusing curent of 4mm² wire is 280A, which I assume is well above the maximum fuse rating required.
I am not 100% sure why they have this rating, but I suspect it is for reverse current protection of the bypass diodes.
4) You average surge is a MASSIVE amount of power. I have seen copper wires vapourised by a near by lightning strike. There is no way that tiny little box is going to absorb that amount of power. It will vapourise within milli-seconds and let the remaining surge toast all your hardware.
Instead, they are designed to short circuit the surge to ground, which produces a massive overload current through the protection device. This opens the protection device, cutting the load off from the source of the surge.
Please read the datasheet of the SPD you intend to install to learn about the minimum installation requirements.

In my opinion (for what it is worth), I think mostly correct:
AC and DC cannot run in the same conduit
Correct. DC and DC also can not run in the same conduit, unless all cables are rated to the highest voltage in the conduit.
All MCB’s (Micro Circuit Breakers) must be correctly sized for both Grid & Load
Correct. If the inverter manual specifies breaker size, you must never go higher than that, although you can go lower. Must also never be higher than the wire rating.
Each Solar Installation must have a separate Earth spike which must read less than 10 ohms (if not then add a 2nd or 3rd spike approx. 1m away and join them) - The DC DB / Combiner box / Solar Panels would be connected to this newly installed earth spike
Only required if the inverter requires this (depends on the type of internal surge protection).
Every Panel must be joined to the next panel by 6mm earth wire (you cannot just earth the Rails)
Only if required by the rail or panel manufacturer, otherwise the rails (aluminium rails only - other materials may be different) meet all the legal requirements of earth conductors.
You must run the positive (Red) wires in a separate conduit and must include the earth in that conduit. If you have multiple strings and have separate conduit for each strings positive wire, then you must include the earth wire in each conduit.
Never seen anything like this before?
Within the Combiner Box, you need to fit Bootlace Ferrules at the end of each Solar wire (stranded wire). This is required for both single wires (single wire bootlace ferrule) and where 2 wires are going into a MCB (twin wire bootlace ferrule)
As far as I can tell, not yet a legal requirement in SA, but will be shortly, and is a really good idea.
For your Inverter installation (Grid and Load connections), you cannot just use the earth wire (normally a single copper wire) contained within the flat Twin & Earth wire, as this is normally thinner than the actual load carrying wires (e.g. 6mm or 10mm). To be compliant you would need to run a separate earth, which is the same thickness as the current carrying wires, between your Main DB board as well as your Essential DB board.
Sort-of correct. For fixed installation, the earth must be min 10mm² copper - but not necessarily the same size as the phase conductor.
For your Inverter connections (Grid & Load), the earth of the Load input (in the inverter) must be bridged (I presume bridged to the Grid earth). From what I was told, if you do not do this you may have a floating voltage between Neutral & Earth especially prevalent during load shedding)
Must definitely be bonded - but using a bonding relay (some say to use a permanent bond, but this seems to be against SANS regs - many arguments about this).
Your Inverter casing must be earthed to this same earth
Correct
Your batteries must also be earthed to this same earth
Correct
 

An often overlooked part of the regs is:

So, basically, you must provide a CoC for any installation work you do, and it would be reasonable for the client to assume that this was included in the quote.

There is not enough information to be sure the solar system will pass CoC.
BUT the seller must provide a CoC covering the entire electrical installation. So you should insist that they provide additional CoCs covering those exclusions.

There is not enough information to be sure the solar system will pass CoC.
BUT the seller must provide a CoC covering the entire electrical installation. So you should insist that they provide additional CoCs covering those exclusions.

In an ideal world, your rant might be correct.  But you are ignoring a number of real world practicalities.
Solar input is variable. In cloudy+windy conditions, you can get very sudden Isc changes from 0 to 130% (or sometimes more) of rated Isc.
Also, where is the MPPT point?  With partial shading, it could be just about anywhere within the parameter space, and sampling algorithms can go to very high duty cycles at times.
So, the MPPT needs to be able to reliably withstand a sudden current increase from almost 0A to Isc x 1.3, even while the PWM is operating at high duty cycles.  This maximum withstand current will be determined by the transistor rating, inductor size (current ramp rate) and current sense feedback speed.
So, in order to guarantee reliable operation, MPPT manufacturers must either heavily over-design the hardware (expensive), or set input current limits.
Generally max input Isc will be quite a bit higher than max continuous input current (because you really don't do an MPPT scan _that_ close to 100% duty cycle).
Newer Sunsynk spec sheets reflect this:

But I don't know if that higher Isc rating is related to hardware/software revisions, or generally applicable to all 5kW inverters.
Even then, 17A is still lower than Isc of 605W panels, so if you do go there, don't expect any warranties to be honoured.
 

It is pretty much impossible for the grid frequency to vary that much.
That would mean either a measurement fault (inverter), or a significant amount of noise/non-linearity on the supply, which is causing bad measurements.  I would guess the latter, but no idea how to test without the proper equipment.

Possibly one of the most comprehensive tests was done by Sandia National Labs:
https://iopscience.iop.org/article/10.1149/1945-7111/abae37/pdf

The bottom chart shows the total kWh discharged from the battery from new until it degraded to 80% of its initial capacity.
There is roughly 20% improvement between 100% and 20% DoD.  The difference between 60% and 20% is negligible. Would have been nice to have more data points to find where the knee point is, but it is certainly not much to be gained going much below 60% DoD.
 
What is striking though, is how much difference other factors (temperature and C rating) make.  If you really want the most from the cells, then:
1) keep them cool, and
2) stick at or below 1C discharge.

If you want some science, try:
https://en.wikipedia.org/wiki/Earth's_energy_budget
Some basic average power numbers from 2019:
total geothermal energy: 47 TW total human energy production: 18 TW total photosynthesis (biomass capture): 140TW Big numbers.  But what is the total incoming solar power?
173000 TW
Now, the law of conservation of energy says that total power inflow must equal total power outflow, or temperature will keep on rising.
You can do 10x more biomass capture, and it won't even move the dial.
To get rid of that amount of excess energy, the only real option is infra-red radiation into space.  And to optimise that, the only option is to reduce green house gasses (which trap infra-red radiation in the atmosphere).

If you want some science, try:
https://en.wikipedia.org/wiki/Earth's_energy_budget
Some basic average power numbers from 2019:
total geothermal energy: 47 TW total human energy production: 18 TW total photosynthesis (biomass capture): 140TW Big numbers.  But what is the total incoming solar power?
173000 TW
Now, the law of conservation of energy says that total power inflow must equal total power outflow, or temperature will keep on rising.
You can do 10x more biomass capture, and it won't even move the dial.
To get rid of that amount of excess energy, the only real option is infra-red radiation into space.  And to optimise that, the only option is to reduce green house gasses (which trap infra-red radiation in the atmosphere).

If you want some science, try:
https://en.wikipedia.org/wiki/Earth's_energy_budget
Some basic average power numbers from 2019:
total geothermal energy: 47 TW total human energy production: 18 TW total photosynthesis (biomass capture): 140TW Big numbers.  But what is the total incoming solar power?
173000 TW
Now, the law of conservation of energy says that total power inflow must equal total power outflow, or temperature will keep on rising.
You can do 10x more biomass capture, and it won't even move the dial.
To get rid of that amount of excess energy, the only real option is infra-red radiation into space.  And to optimise that, the only option is to reduce green house gasses (which trap infra-red radiation in the atmosphere).

It is not an isolated system, so the discussion is meaningless.
About 31% of sunlight is reflected away from Earth and goes into heating the rest of the universe.  A large amount of incident energy is also re-radiated into space as infra-red emissions. The exact percentage which gets reflected/emitted depends significantly on cloud cover and atmospheric composition.
If the Earth-Sun system was indeed isolated, the entire system would be a plasma at a few million degrees.  Instead, it is the delicate balance between incident and reflected/emiited radiation that maintains the Earth in a liveable temperature range.  The tiny amount of chemical energy released by humans is insignificant at this scale.

It is not an isolated system, so the discussion is meaningless.
About 31% of sunlight is reflected away from Earth and goes into heating the rest of the universe.  A large amount of incident energy is also re-radiated into space as infra-red emissions. The exact percentage which gets reflected/emitted depends significantly on cloud cover and atmospheric composition.
If the Earth-Sun system was indeed isolated, the entire system would be a plasma at a few million degrees.  Instead, it is the delicate balance between incident and reflected/emiited radiation that maintains the Earth in a liveable temperature range.  The tiny amount of chemical energy released by humans is insignificant at this scale.

It is not an isolated system, so the discussion is meaningless.
About 31% of sunlight is reflected away from Earth and goes into heating the rest of the universe.  A large amount of incident energy is also re-radiated into space as infra-red emissions. The exact percentage which gets reflected/emitted depends significantly on cloud cover and atmospheric composition.
If the Earth-Sun system was indeed isolated, the entire system would be a plasma at a few million degrees.  Instead, it is the delicate balance between incident and reflected/emiited radiation that maintains the Earth in a liveable temperature range.  The tiny amount of chemical energy released by humans is insignificant at this scale.

It is not an isolated system, so the discussion is meaningless.
About 31% of sunlight is reflected away from Earth and goes into heating the rest of the universe.  A large amount of incident energy is also re-radiated into space as infra-red emissions. The exact percentage which gets reflected/emitted depends significantly on cloud cover and atmospheric composition.
If the Earth-Sun system was indeed isolated, the entire system would be a plasma at a few million degrees.  Instead, it is the delicate balance between incident and reflected/emiited radiation that maintains the Earth in a liveable temperature range.  The tiny amount of chemical energy released by humans is insignificant at this scale.

Possibly one of the most comprehensive tests was done by Sandia National Labs:
https://iopscience.iop.org/article/10.1149/1945-7111/abae37/pdf

The bottom chart shows the total kWh discharged from the battery from new until it degraded to 80% of its initial capacity.
There is roughly 20% improvement between 100% and 20% DoD.  The difference between 60% and 20% is negligible. Would have been nice to have more data points to find where the knee point is, but it is certainly not much to be gained going much below 60% DoD.
 
What is striking though, is how much difference other factors (temperature and C rating) make.  If you really want the most from the cells, then:
1) keep them cool, and
2) stick at or below 1C discharge.

Possibly one of the most comprehensive tests was done by Sandia National Labs:
https://iopscience.iop.org/article/10.1149/1945-7111/abae37/pdf

The bottom chart shows the total kWh discharged from the battery from new until it degraded to 80% of its initial capacity.
There is roughly 20% improvement between 100% and 20% DoD.  The difference between 60% and 20% is negligible. Would have been nice to have more data points to find where the knee point is, but it is certainly not much to be gained going much below 60% DoD.
 
What is striking though, is how much difference other factors (temperature and C rating) make.  If you really want the most from the cells, then:
1) keep them cool, and
2) stick at or below 1C discharge.

Possibly one of the most comprehensive tests was done by Sandia National Labs:
https://iopscience.iop.org/article/10.1149/1945-7111/abae37/pdf

The bottom chart shows the total kWh discharged from the battery from new until it degraded to 80% of its initial capacity.
There is roughly 20% improvement between 100% and 20% DoD.  The difference between 60% and 20% is negligible. Would have been nice to have more data points to find where the knee point is, but it is certainly not much to be gained going much below 60% DoD.
 
What is striking though, is how much difference other factors (temperature and C rating) make.  If you really want the most from the cells, then:
1) keep them cool, and
2) stick at or below 1C discharge.

When cleaning up tabs I spotted this datasheet which could give you an idea just how tricky it is to (legally) use wire for off-label purposes:

When used as 'welding cable' the 50mm² cable meets the legal requirements to be rated for 280A. Exactly the same cable, when used for power supply or panel wiring, can only be legally rated at 196A.

You can get a lot of general information at OpenInverter.org:
https://openinverter.org/wiki/Main_Page
Battery voltage depends largely on power.  Small scooters/golf carts will usually use 48V. Low power city cars 96V.  Most full size EVs 400V. Hypercars up to 1000V.
(Some 400V systems are 2 bank series/parallel arrangements - discharge in parallel, charge in series to reduce charging currents.)
Small inverters are free air cooled. Intermediate ones fan cooled. Large ones water cooled.
Output voltage is effectively around Vdc/sqrt(2) RMS.
Yep - no filtering - only snubbers to kill the worst of the HF components.
Most controllers are torque demand, so would be duty cycle controlled with frequency limits.
Most have peak 98% efficiency, down to 96% or so under worst case conditions.
No physical standards on the control ports (yet), although there is some standardisation happening at the logical (CAN/LIN) level - but not wide spread yet.

You can get a lot of general information at OpenInverter.org:
https://openinverter.org/wiki/Main_Page
Battery voltage depends largely on power.  Small scooters/golf carts will usually use 48V. Low power city cars 96V.  Most full size EVs 400V. Hypercars up to 1000V.
(Some 400V systems are 2 bank series/parallel arrangements - discharge in parallel, charge in series to reduce charging currents.)
Small inverters are free air cooled. Intermediate ones fan cooled. Large ones water cooled.
Output voltage is effectively around Vdc/sqrt(2) RMS.
Yep - no filtering - only snubbers to kill the worst of the HF components.
Most controllers are torque demand, so would be duty cycle controlled with frequency limits.
Most have peak 98% efficiency, down to 96% or so under worst case conditions.
No physical standards on the control ports (yet), although there is some standardisation happening at the logical (CAN/LIN) level - but not wide spread yet.

You can get a lot of general information at OpenInverter.org:
https://openinverter.org/wiki/Main_Page
Battery voltage depends largely on power.  Small scooters/golf carts will usually use 48V. Low power city cars 96V.  Most full size EVs 400V. Hypercars up to 1000V.
(Some 400V systems are 2 bank series/parallel arrangements - discharge in parallel, charge in series to reduce charging currents.)
Small inverters are free air cooled. Intermediate ones fan cooled. Large ones water cooled.
Output voltage is effectively around Vdc/sqrt(2) RMS.
Yep - no filtering - only snubbers to kill the worst of the HF components.
Most controllers are torque demand, so would be duty cycle controlled with frequency limits.
Most have peak 98% efficiency, down to 96% or so under worst case conditions.
No physical standards on the control ports (yet), although there is some standardisation happening at the logical (CAN/LIN) level - but not wide spread yet.

Makes sense, but dang - a 3 phase Type B RCD probably cost more than the charging station...

Yeah...  I think I would trust the manufacturer's web site over chatgpt's hallucinations.
While it is probably perfectly safe to use it on 12V DC, using AC components to break DC circuits is quite literally playing with fire.
Rather use proper DC rated components.

Yeah...  I think I would trust the manufacturer's web site over chatgpt's hallucinations.
While it is probably perfectly safe to use it on 12V DC, using AC components to break DC circuits is quite literally playing with fire.
Rather use proper DC rated components.