After having some loads on non-essential I moved everything over to essential a long time ago. My advice to anybody installing a new system with a 5kw inverter or more and some batteries and panels has since then been to put everything on essential - and if you have loadshedding switch appliances off by hand or smart breakers. This at least gives you the option to use these appliances if you want to during loadshedding and have extra capacity available.
But at every new install a friend or family member is doing - the installers want to split it up into essential and non essential.
Is there a good reason to still split into essentials and non essentials?
It allows you to install a smaller, less expensive inverter, and less battery capacity (same reason) without the risk of overloading. The transfer switch in the inverter may also not be sufficient, for example some only has a 32A or a 40A transfer switch, which requires either bringing the whole house down to that limit, or leaving some large loads on the non-essential side.
If you are on the fence, I suggest a second change-over (who here calls it their doomsday switch?) to move them over to essentials during an extended outage.
I think installers do this because most customers are 1) cost-sensitive, and 2) stability is important, some customers first call the installer to complain that the power is off, and then remember that they were told to take it easy during an outage…
My speculation is that it is to mitigate the worst case scenario: overloading the inverter (causing potential damage) . Perhaps there is lack of standardisation for allowing ‘non-essential’ appliances to be manually enabled via switch, smart breaker etc. . I guess from an installer and supplier perspective: it is not worth the risk, and extra work (currently out of scope) to allow non-essential devices to be turned on. Then again you can overload a system by plugging in simultaneous 2kW heaters, and turning the kettle on via plugs categorised as essential.
As the industry matures I suppose it will become standard to not physically limit non-essential loads as each breaker, or even plug socket would be individually monitored and managed.
It makes sense with a smaller inverter - lets say 3kw or less.
When I had some stuff on non essential it was super irritating to have load shedding while the sun is shining and have a lot of excess power, but you cant turn on your oven…
That was more irritating than turning off a few things after tripping the inverter. Though I could see someone could maybe complain about his inverter tripping if he didnt know he was using lots of power.
P.S. everyone that I convinced to install everything on essentials thanked me later. Even though it took a bit of convincing to get them and the installers to do it.
What you are talking about is the management of maximum demand.
Occasionally, I post this product, which has flavours with various current thresholds.
I don’t know why it isn’t a standard feature in DBs. So much can be done simply with a multiple of this product or even a cascade of them so that loads can be prioritized and not be on concurrently.
(It always power to a second circuit if the first circuit is below a certain threshold).
I think people get too used to having power all the time. Many people on PV systems often do not even realise there’s loadshedding.
I have a 5 KVA Victron Multiplus, and geyser, aircon and oven is on the non-essential side.
I’ve seen my family:
Run the kettle (~2kw)
Run the hairdryer (~2kw)
Run a flatbed toaster (?)
at the same time.
Mostly due to ignorance of the fact that somebody else turned on the high-draw items.
Most people have no idea what the watts usage of their solutions are, nevermind how KWh works. I’d be willing to bet one person in every household knows and the rest are ignorant. The people in the household who knows are the ones on this forum
I agree that smart-switches could help, but then I’d pretty much turn them off at the beginning of loadshedding/an outage (or just before) so that you enter way under, and then CAN turn on specific items as need arise. Otherwise my aircon would just happily stay running into loadshedding, and my wife would probably just turn on the oven too.
I think that applies even to 5kW, depending on the home. My house, for example, has a pool, and the main hot water source is a 900W heat pump. The odds of heating water while the pool pump is running is quite good, which means I will very likely leave at least the pool pump off the inverter if I had only a 5kW.
I am currently upgrading to a Multi-RS, which is in theory 6kW, but in reality it is 4.5kW continuous. That is almost double what the 3kVA could do (which is only really capable of 2.5kW for extended periods), and I still think I’m going to leave things as they are. During an extended outage, I’ll rig an extension cord to the pool pump
Of course, this entire thing may get revisited at some point. For now, that’s the thinking.
You can also easily turn off some things during load shedding with node-red. I used to do that when I had a 5kva multiplus. Having 10kva of inverter power however sorted that out. Its basically always enough.
Also, they may not have an intuitive feel for it. Just yesterday, I observe the wife stuffing a bean bag into microwave oven, and I say to her: Hang on a second, you’re about to trip the inverter, the dishwasher is heating water!
The solution is simply to open the dishwasher door (so it pauses), heat the beanbag, and then close the dishwasher door again. But it is sooo easy to forget. At my previous house, the answer was simple: The skullery didn’t have backup power. In this house, the wiring was already set up that way, so we have to live with it.
What I deduced … you get a 3kva … all on critical … and the LS hits … and it trips.
Get a 5kva … same.
8kva … still there.
10kva … less.
15kva … seldom if ever.
Why, the 63a main breaker in most home DBs seldom trips due to overload.
To automate it all is definitely an answer, till the automation fails for whatever reason.
So here is my 2 cents … KIS … apply ergonomics, with a twist …
Not “designs or modifies the work to fit the worker, not the other way around”.
But “designs or modifies the work to fit the budget, not the other way around”.
Force people to think about what they are switching on … if not, then it is off. Simple.
Running a 5Kva too and I’ve never tripped it. That being said, my big current consumers are on the non-essential side. Still need to get myself 'n dooms-day switch.
The one I’m seriously considering moving over permanently is the borehole - it consumes ~800w, so even with it running when LS hits I’m probably not going to trip anything.
Oven → replaced by the airfryer and gas camping stove, works well enough.
Gesyer → its an EV tube one in any case, so it will have to do. If there’s no sun I’m going to worry about battery SOC in any case and NOT warm water.
Aircon → nice but probably ok to live without. Fans / fireplace / gas-heater
Borehole → not necessary if it is loadshedding and City of Tswhwane / Rand Water keeps their act together. Extended outtage and water problems? That’s my bigger concern.
One caveat though, certain loads are just too big to be comfortably carried with a smaller inverter. Our tumbledryer for example sometimes uses up to 3kW. So load shifting isn’t possible if the load itself is too large and it isn’t practical to make the load smaller. I find myself always looking at the wattage of an appliance. We were recently shopping for kettles and most of the kettles we liked were 3kW. Eventually we found a 2kW one. People are so impatient!