Yellow Measure

So that settles it then. I guess that it's an opportunity for an installer with a spare 8K SS to loan/rent it to you, and send your unit in for repairs. But here's another plan: how about buying the new Solis S6 Pro 8K that Powerforumstore currently has on special, install it and then you can send the SS in for repair and sell it when it comes back? It's a way better unit, with far better support.

True. If Sunsynk want to be perfectly correct about it, they should be insisting on a datacomms technician to attend the call, because it has to do with the electrical signal characteristics of the RS-232 interface. I am willing to bet that the vast majority of electricians have never encountered it before, making them just as unqualified (and ill-equipped) as you. Can you imagine if the problem was not power, and they need him to plug a loopback connector in and run a BERT? Or to measure the delay between RTS and CTS? 😀 @PearlJam I know the old field "engineering" motto used to be that a layperson with enough of spares could diagnose and fix just about anything, but it does have its limits, which brings me to my point (and I guess Sunsynk's as well): If there is a fault condition with a sufficiently high voltage (say 40V) on pin 9 or 5, it could have smoked the dongle, as well as the new one that you plugged in. If you measure between pins 9 and 5 (ground) you should get +12V. Even less (down to 5V) should power the dongle, but if it's lower than 5V then it won't. If it's way high, then not only is the board faulty, but you have 2 unserviceable dongles as well. 😬

AC or DC?

It looks like higher import tariffs on renewable energy equipment are being planned, in the name of "stimulating local production of components in the renewable energy supply chain". "One of South Africa’s largest electrical product distributors warned that planned import tariffs on renewable energy equipment could keep solar self-generation out of reach for lower-income households. The International Trade Administration Commission (ITAC) recently published its preliminary determinations after a year-long review of import tariffs for solar, wind, and battery components. ITAC recommended that the trade minister align South Africa’s import duties on renewable components to World Trade Organisation rates. In many cases, the tariff rate is 15% of the declared value of the goods. South Africa already imposed a 10% tariff on solar panels and modules in June 2025. ITAC also recommended that the minister impose an additional 15% ad valorem duty on assembled lithium-ion batteries. The measures are aimed at stimulating local production of components in the renewable energy supply chain, balanced with ensuring local deployment of renewables." New import tariffs will reserve solar power for rich Sout...One of South Africa’s largest electrical product distributors warned that planned import tariffs on renewable equipment could keep self-generation with solar out of lower-income households’ reach.

🥱 I rest my case.

I take great pride in paying all of my bills on time. Clearly, you did not bother to read my (albeit lengthy) post before launching judgement and ad hominem attacks. A pretty poor reflection on your ability to read with comprehension.

BTW I have counted at least 5 AI bots and one AI spammer in this thread, no idea who funds them or what their intentions are : SASSA UPDATES brockbat3 Shakeel4811 MEPCOMIS KellyMichael SASSA

I did my humble little solar install in August 2020. At the time I had around 980kWh credit on my prepaid meter, which for about 4 years I hardly ever used. Around 2 years later (circa 2022) City Power sent their "auditors" in to check the meter. They left with no findings. Then came 2023, where they upgraded all the prepaid meters to "Smart Meters" in the HOA. When they came to mine, they said that they could not upgrade it, because there was over 500kWh on the meter and they were limited to transfer credits of 500kWh and under. So I was overlooked on that upgrade. I then decided to use my credits, after all, I had paid for them and they were not doing me any good sitting in the meter. So every month I used a few kWh, and I started neglecting lifestyle changes that I had made back in 2020, like not roasting a small eisbein at midnight when I got the munchies. The "auditors" came and went a few more times, and the prepaid meter's crypto key update was also duly performed in 2024. Fast forward to December 2025. I was going away for holidays, and my prepaid meter showed less than 1 unit left. I did not bother topping up because I would not be there, and my system doesn't need the grid, but I didn't budget for the inverter pushing some back to the grid, which it usually does when a big load stops, and which the meter counts as usage. Around 28 December I noticed that the grid had disconnected, and upon returning home on 2 January 2026, I tried to purchase electricity, but no go, I was advised to call City Power. When I called them, they were extremely unhelpful, telling me that I needed to come in to see them. I drove over to City Power's offices, which was in disarray. As luck would have it, there was a big power outage, and they had no power, nor any backup, and the ETR was unavailable, so all visitors were told to come back another day. I insisted on seeing someone, but they said that all staff had gone home due to the power outage. I stuck to my guns, and told them that I would not be leaving. They eventually extracted a surly and most unpleasant Marxist drone The Borg from his office. He listened to my story, then disappeared back down the dark corridor. After 45m of waiting in the stuffy, unlit foyer, I went hunting for him using my cellphone flashlight. I found him sitting in his dingy, unlit office, staring into his laptop. He grunted at me, and motioned me to sit down. He asked me why I was not buying electricity from them. I repeated my story again to him. He then asked for my rates and taxes number, and proceeded to do checks on my CoJ bill. Finding nothing amiss there, he told me that he would not reinstate my meter until I paid him a R15,000.00 "fine" for not using electricity. I protested, and he scowled at me. I scowled back. Another round of argument, where he changed his story: It was now no longer a "fine", but the R15,000 had to be paid because that was what a smart meter would cost. Yet another round of argument. The situation was beyond bizarre, here I was arguing with The Borg about why I should not be "fined" for not using City Power electricity, whilst sitting in an unpowered, unlit, stuffy City Power office. Eventually he conceded that he would "raise the matter with a senior manager", who was on leave at that time, and get back to me. Seeing that it was going nowhere, I resigned myself to my fate, went back to my 2020 lifestyle of frugality, and started pricing batteries. Needless to say, The Borg never bothered to come back to me, and I didn't bother begging him to either. I placed an order with Wimpie from The Powerforumstore, and soon my batteries arrived. I decommissioned my 3x US3000 Pylontechs and donated them to my brother, and installed my new 32kWh storage. I am very happy, because not only have I defeated Marxism and The Borg, but I can now roast a leg of lamb and a few Eisbeins at midnight again. Bon Appetit!

Is this special still on?

It is not often that you and I agree, so I double-checked just to be sure 😁 Spot on! Yes, or it could the the form of an inverter that is pre-wired, mounted against the wall, and ready to pump electrons at the flick of a switch (or two). That's what I would refer to as a "Warm Standby".

Agreed, I stand corrected (in the strict technical sense), but then allow me to re-phrase: Putting two inverters in parallel operation increases the probability of inverter failure by 2. That's the law of averages at work, and I am not prepared to debate it 😄. It also creates redundancy (hot standby) if, and only if: A system fault arises due to an inverter failing, and not an external cause; The system has capacity to operate under the exact same same load conditions (i.e in normal parallel operation no inverter exceeds 50%); The faulty unit can be repaired, or another sourced, and replaced, in a reasonable timeframe (and hopefully a maintenance slot). It creates derated redundancy (degraded performance) if only 1 and 3 are true. Not everyone's needs are the same, and this may appeal to some, depending on business case and application. I would agree with you that external causes are far more common though, and therefore cold standby is also a good option (i.e. buying 2 inverters, putting only one into operation, and store the other in a cool, dry place. The advantages over a parallel system would therefore be: Simplicity vs complexity; Less chance of an external fault affecting the second inverter; Less probability of inverter failure; and Replacement is on site, no waiting for repairs or container ships to offload. The only disadvantage that I could see would be an outage at a potentially inconvenient moment, but it could soon be rectified. So if availability is a thing, cold standby is a good option, and in some cases even better.

If system availability allows for degraded operation, yes. A parallel system would lose capacity, whereas a system with a redundant component would increase system availability. Please tell me how MTBF works.

If there is an external cause for the failure, like a surge from the grid for example, then both could fail at the same time. If the cause is something internal to the inverter, like component failure, then the MTBF comes into play. The M in MTBF stands for Mean, an arithmetic mean, so whilst it could happen at any time, logically an inverter that has worked 60,000 hours would have a greater chance of failure than an inverter that has worked for, say, 240 hours. But it does not eliminate it. That's what I stated, degraded service. My point was that the odds (probability) of failure is doubled by adding an inverter in parallel, and tripled by adding two etc.

I never really understood this logic. Components have a MTBF rating (Mean Time Before Failure) which is a manufacturer's estimation of the average time that a component would last before if failed, requiring replacement. For an inverter this may be (for arguments' sake) 100,000 hours (under pristine conditions) but in reality between 60,000 and 90,000 hours. If two inverters are placed in parallel, both are working, heating up and cooling down. The odds of them both failing together is fairly high if that are connected to the same circuitry and the root cause is external. Let's say, for arguments' sake we put the odds at 30%. That means that 70% of the time, one will remain working. So we have degraded service, resulting in the shedding of some (hopefully unimportant) loads, but not a complete outage. But because that one is taking on at least some additional load (assuming that there is headroom) it will heat up more, and increase its chances of failure due to these increased loads. So the chances are greater that it will also fail in the time that it takes to source and replace, or repair and replace the failed unit. Let's say by another 30%. And then it also still has its MTBF rating. When two components are placed in parallel, you effectively halve the MTBF rating of both components. So a rating of 60,000 hours becomes 30,000 hours, increasing its chances of failure overall, at the outset, not only once one fails. To me, if a component is that important, then it should be backed up by a similar component in the cupboard, not one working in parallel. Does anyone other than myself see this, or not?

In summer (cooling only) yes, but if you use it to heat a room in winter, the figures will be a little different. That's my experience in anycase. I decided to install an 18000BTU TCL inverter aircon in my home office, and was so impressed with its efficiency that I installed another 24000BTU TCL inverter in my living room, all on a baby 5K Sunsynk inverter. Both worked well during the summer and I have used both simultaneously for many hours. I did some testing on the heating side though, and it consumes about 10-25% more power, all depending on a number of factors.