How does your output voltage look? Is your fridge on the inverter or not?
For the most part, that device is certainly not going to do any harm, and if it makes the insurance happy, go for it!
There is now also evidence, so far still anecdotal but I’m hoping someone will throw a scope on it and maybe do a Fourier transform, that the South African grid isn’t fully sinusiodal everywhere in the country. I checked mine at home and I get a perfect picture, with almost everything bang on 50Hz, and then the usual harmonics at 150Hz, 250Hz, 350Hz… small little bumps. But I’m beginning to hear noises that in the Northern parts, there are places it’s not as clean.
Not that most appliances will care about the waveform though…
With all due ill will and anger towards Eskom… some of this is local. The thing I am presently contemplating: What effect does the following have:
Poor maintenance on your local infrastructure, eg the transformer down the street…
What’s the contention ratio, by example that 100kVA transformer down the street, is it running at 80kVA or 105kVA?
Are you close to the transformer, or on the end of a longer run?
How many other embedded generators are on the same transformer?
I’m beginning to think a lot of the problems are more local than we think. If you’re seeing a 129V dip, but nobody else in Cape Town has seen it… odds are it’s not Eskom. It’s someone in your neighbourhood who started his air compressor… and a sign that something is not tip top down the street
Can see where your mind is going, determine the cause. I can respect that.
However, whatever the cause, chances are it is out of my/our control. So, the logical deduction then is to protect what is running on our critical load DB’s, incl our inverters, in our homes.
Over that I/We have control.
Thinking about that, I wonder how much of CoCT infrastructure is being damaged and strained, by “ANC” caused LS.
@TheTerribleTriplet - what does this device add, on top of what the inverter does? I don’t understand how it can react “quicker” to the grid voltage falling than the inverter? Genuinely curious (-:
So the inverter is supposed to react to voltage decreases by increasing its output, that’s where the ESS feed-in / balance thing comes from. So my guess would be that it goes:
ooh, slight drop, increase my output
oh shit, too much, ALARM!
ABORT, drop the grid
hey, move along, nothing to see here
If your device monitors voltage and just drops immediately instead of trying to support it, that might be faster, assuming it’s trying to be fast?
I’d guess the “support the voltage before dropping the grid” causes the overload alarms when LS kicks in. Just flipping the breaker doesn’t cause that kind of problem.
If you run a MultiPlus without a grid code in UPS mode, it doesn’t have that issue. If I recall correctly, UPS mode is disabled when in ZA grid code mode. Unsure if others still have UPS or not, but it feels counterintuitive to run in “UPS mode” while also supporting feedback / grid-tied at the same time?
Victron syncs to the grid after ±65seconds, in that time Eskom runs the show, right at the time when there are potential problems when LS is over.
So the main thing @AlbertDeJongh is to keep Eskom disconnected for 10min when LS is over, then the inverter can sync.
The 2nd thing is I don’t want to wait for 195.5v to disconnect, it must happen at ±215v and then stay disconnected for 10min. Remember the pronounced changeover we noticed on the lights?
Also don’t want to go above 250v, and if it does, stay disconnected for 10min.
Indeed, thanks for asking the question. I know that in some areas they increase the voltage where the Multi disconnects for exactly that reason, so it doesn’t pull down to 180V, and so the changeover gap is a little smaller. It all comes down to energy stored in capacitors and other momentum-keeping devices, and the energy is proportional to the square of the voltage. If you have a stable grid voltage that never drops below 210V, there is no reason why you cannot make this a little higher.
Personally I would not use 215V. During serious peak use in winter, my neighbourhood shows as low as 212V. 205V seems like a safer limit to me.
If those voltages could be easily adjusted, legally, as well as the time it takes to connect to the grid, not sync, connect, I would not have had to buy an AVS30.
And, I would bet, fewer repairs too.
But, even if Victron does that in future models, I would still need to upgrade. I suspect the AVS30 would be cheaper.
