hj2k_x
Honorary Master
Because doing it eventually kills the inverter itself? Fair enough.
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Mike's (non-Sunsynk) System
- Thread starter Mike Hoxbig
- Start date
hj2k_x
Honorary Master
Is it just the Sunsynk that has this "excess" or does brand not matter and it's something to do with the science of it all?
Speedster
Honorary Master
Each brand will have a different spec.
Mike Hoxbig
Honorary Master
Sunsynk and Deye are the same thing and they'll both do it. Most reputable brands will.
If it's 8kW, your installer will set this as the maximum to safeguard against this happening.
Also there's DC input and AC output. The 10kW you're referring to is the DC input, i.e. how many panels you can connect. The MPPT range on the Deye/Sunsynk inverter is spec'd at 125V - 425V.
This means that for a 455W panel like the one I have (you can check the spec sheet of the panel you want to get), the maximum voltage for each panel is 41.8V. So you would need a minimum of 4 panels per string and can safely take a maximum of 10 panels per string (for a total of 20 for the inverter).
Putting 8kW of AC load on the inverter isn't as easy as it sounds though. For typical usage this shouldn't happen, and you start becoming a bit anal about monitoring your usage. You literally have to have your geyser, oven, pool pump, microwave, kettle and a couple of other things running at the same time...
Yup the 8kw limit is more an issue when you switch eskom off as it cant pull excess from the grid. But to be honest we run our entire house on essential and have had 3 occasions in the last 100 days where it just momentarily spiked over 7kw and that was running the kettle, oven and stove (+baseload) all at once.
Mystic Twilight
Expert Member
This is usually purposeful over-engineering to provide tolerance, reputable brands would have a fairly good margin while no-names would have minimal if any (those would trip before you even reach the rated amount). But you shouldn't rely on those margins for continuous use, it will wear away the integrity and lifespan of the component.
Speedster
Honorary Master
I'm not sure it is only that. The inverter part has a limit (I.e. conversion from DC to AC). Adding extra AC from the grid doesn't necessarily strain the components.
hj2k_x
Honorary Master
It was that last part I was wondering about. Whether the inverter has to "invert" the power that's coming from the grid at all. It's AC to AC from the grid
hj2k_x
Honorary Master
I guess I'm just trying to plan ahead for worst case scenario. We have two households using the electricity. So there could be days when there's heavy load on the system. Aircon. Washing machine. Tumbler. Kettles. Oven. Etc. Plus base loss which includes pool pump, borehole pump, sprinklers sometimes...
TheChamp
Honorary Master
It has limits for both the inverted output and the pass through output, so you don't have a free will on the pass through, that should also be managed even though it is AC to AC.
hj2k_x
Honorary Master
Fair enough. This is my washing machine, plugged into a smart plug which monitors power usage. Is the current power figure one the relevant one? Is that 2143W?
TheChamp
Honorary Master
Unfortunately it is, 9A current draw, that's massive, I wasn't aware they are such electricity guzzlers.Fair enough. This is my washing machine, plugged into a smart plug which monitors power usage. Is the current power figure one the relevant one? Is that 2143W?View attachment 1248442
hj2k_x
Honorary Master
I did only peak at that for a little while.
It's meant to be an energy efficient Bosch. And the overall usage figures would support that idea.
But those high peaks is why I was worried about total peak load at any given stage.
If each household runs a washing machine and then boils a kettle, it doesn't look too good for peak load...
TheChamp
Honorary Master
I see, nothing abnormal then, the 8kW can easily handle a couple of loads, as long as they are managed well, you will need to move some of the heating elements to gas then you can easily manage with commonly used items like the kettle microwave and the washing machine.
This is the reason we went 8kw use as you want don't have to think abt it. As I said we have everything in essential
hj2k_x
Honorary Master
Indeed. I suppose I'll have to work it all out. See if I need to keep some large appliances on the grid side just in case. Pretty sure these aircons, while very efficient overall, peak pretty high as well. Going to be using them to heat in winter also.
TheChamp
Honorary Master
Two households can pose a challenge even with an 8kW, some fancy footwork is going to be necessary.
Speedster
Honorary Master
I think I'm going to set my geysers, pool pump or borehole to switch off if the load approaches the max. I'm not sure if the inverter can do that natively, but I should be able to do that via HA.
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hj2k_x
Honorary Master
I see there are also larger inverters even. Like 12kw upwards. But maybe it would make more sense to them do one 8kw and one 5kw if it's really going to be an issue.
hj2k_x
Honorary Master
I see there are also larger inverters even. Like 12kw upwards. But maybe it would make more sense to them do one 8kw and one 5kw if it's really going to be an issue.