I do stay connected. But the inverter can still be tripped by too large a demand on the backup side. Whether we have grid power available or not.
In practice it’s rare because we are aware of the problem and have disciplined ourselves. The first couple of weeks living with this system trips were frequent.
I also tried to include all circuits to my setup but ended up removing some loads.
The oven was too heavy and I also removed the stand alone griller. Those big fat elements are murder on inverters!
I have gas stove and oven. But the kitchen is a minefield. I get away with an airfryer, with a kettle, with a microwave, with a dishwasher, but it’s not a good idea to turn them all on at the same time.
When the installation was done an electrician did the DB split, but there was a technician installing panels and so on, and he told me that if he had his way, the entire kitchen would be on the non-essential side.
I told him
A) I like my beer cold, thank you
B) I can always run an extension lead from another room and plug stuff into that.
So the only answer is alternatives where you can, and then discipline.
Just my uninformed ramblings here, but what is the size of your lawnmower?
And is your Goodwe one of of those high frequency inverters?
I know the Victrons to have low frequency transformers, those heavy buggers but I understand them to be much more forgiving than high frequency units when it comes to sudden large power demands.
Because it would be a real problem for me if mine tripped despite the grid being available. I have had a kettle and microwave on, or a 2Kw geyser and either the microwave or kettle on, (without grid) and I have never had a trip with the Multi only being a 4Kw unit.
Lawnmower and geyser simultaneously also no problem.
There the old tech I recon is better
IDK off hand. I don’t know if the steady load is a problem. I know that the start up load is. I am thinking about ways to get a soft starter involved.
I think so.
It is just the lawnmower that gives me a problem. Everything else in the outbuildings sub db is within what the inverter can handle. Hmmmm… except maybe the tumble drier. But that hasn’t been turned on in years, so that’s a theoretical problem right now.
My backup is a good old-fashioned pushing type lawn mower.
My only concern is that I have this switch over put in, I switch over and leave it there. I can’t blame the gardener for assuming that there’s grid power when he notices that the garage lights turn on, or that the pool pump is running. So he’ll plug in the lawn mower and the inverter will trip.
Maybe it’s better to just carry on running an extension lead out to the washing machine.
It is donkey’s years old. Maybe 20 years by now. So I suspect that it was not designed with efficiency in mind.
In theory, the old LF designs peak better. The Multi/Quattro can do 200% for about 1 second. But modern HF jobbies have also improved a lot, for example a Multi RS can do 150% for 3 seconds.
Lawnmowers typically peak around 500% of their nominal power rating. Your typical 1.3kW small unit, I bought one of those for my small lawn during Covid (when I couldn’t pay someone else to do it), should therefore easily start on most of the residential inverters people install.
Your larger 2kW and up units… a 5kVA LF unit may be able to start it, maybe, but you probably need a bit more.
Speaking of a smaller lawnmower. A Ryobi 1300W unit is less than 2k… 
I am think the best and cheapest solution would be to buy an extra extension cable (if needed), and instruct the garden engineer to never ever plug the mower in at the outbuildings.
So that the mower will always run on the essential side. You said this does not cause tripping?
Yes, that’s an option.
But I would simply install a (big) series resistor for a second or two that would get it turning before full power is switched on. It’s that initial inertia from standstill that’s the killer. The figure I remember is 6 times full load current.
You would need a contactor and a timer…
And you must talk nicely to your gardener not to start the mower when it’s bunged up with grass cuttings!
My Goodwe can do 150% for 10 seconds (it says in the manual). This suggests the lawnmower is drawing around 7kW momentarily. The lawn mower doesn’t start turning and then a few seconds later the inverter trips - the inverter trips the moment you try to start the mower.
500% of 1300W is 6.5 kW - so still very close to the limit. And I would have at least a couple of 100 W going on in the house.
No. The whole main house is on the essential side. If we plug the mower in there then the inverter trips the moment you try to start the mower. I haven’t sat with the app on my phone and watched it in real time when the mower starts up, but I assume it draws from grid momentarily.
The outbuildings are not backed up. So when we have outages we can’t use the lawn mower and the pool pump won’t run, which are things that can be tolerated for two hours (four is pushing it). But we also can’t use the washing machine, which causes greater unhappiness (especially if the load shedding starts mid cycle). So that’s where the extension lead comes in. The washing machine doesn’t draw much, so I just run an extension lead from the house to the laundry.
But this is a general principle. It always takes more juice to get a thing moving than to keep it moving.
Though with appliances we can buck that principle with the inverter drives. Remember I mentioned the new deep freeze recently? Never draws much more than 100W? That has an inverter drive, and if you’re bored or it’s late night and the house is still, then you can hear the motor spinning up as it starts. It doesn’t turn on with a sudden noise like the old one did.
I would be an electrician with a fool for a client.
He does not commit that particular transgression. In fact he is quite fastidious about the mower. When he goes away over Christmas he knows that I will likely get a temp in, so he then talks to me nicely! He does not want anybody changing the settings on the mower, and the grass cuttings must be dumped in a particular place.
another idea from the Five Rand store… Have the gardener check every time if it is okay to use the electric lawnmower. Put a notice on the socket where the lawnmower is powered from that requires intervention before use (like “remove before flight pin/tags” on aircraft).
Use a babyproof plug cover or unconnected plug with a laminated label glued to it. (to be reinserted after mowing the lawn).
and/or
wire a light that illuminates when the out building is powered from the inverter for either:
a) gardener to see if no one is around to ask about using the socket, or
b) you to be reminded that the outbuilding is on essential (nice visible location that you will pass often and find close to annoying)
