P1000

You should not be billed for anything other than real power, unless you are a commercial user.

That will probably all be reactive power. The inverter may only generate unity power factor when connected to the grid, so the reactive load is offloaded to the grid. You cannot measure real power with only a clamp.

The upper limit is 1kV, so I think he is quite safe.

This

You can configure it to either export without limit, limit to the lowest phase (like your example), or limit to the sum of power imported in your example case (assuming all phases power factor of 1): L1 = 6.33A L2 = 6.33A L3 = 6.33A Usually the config selected will be determined by how your utility supplier billing works.

No. These inverters will require 100% load balancing. Typically this is done by exporting the same on all phases, but importing what you need - ie the unbalancing is offloaded to the grid.

IIRC, they were 48V and cost just about the same as the 5kW...

I fixed it for you. Remove the AC breakers to make it compliant. To disconnect, make sure the inverter is not generating power, use the DC disconnect on the inverter to disconnect all the PV, open the fuse of the string you want to work on, and then you can work on that string.

VFD usually converts to DC and then generates 3 phase SPWM with IGBTs switching in the 6-16kHz range (typically). Soft starters usually use Triacs (or Triacs made with 2 discrete SCRs each, depending on power level). This means the switching is done at 50Hz, with the peak currents still very high for an inverter. You also have a much wider range of control with a VSD, which allows you to more easily tune it within the limits of the inverter. Thinking about that a bit, the 3 phase Sunsynk would probably be better; matched to 3 phase VSDs.

Yeah, the fuses are also a legal requirement for battery inverters. If you don't have a battery, you can do without fuses, as long as the wires are oversized to greater than 1.56x Isc. Not installing fuses with a battery inverter should mean no CoC. But even if you have a CoC, in the event of a fire, the insurance might not pay out.

The fuse is to protect the wires from making flames. In some inverters there are fault conditions that can connect your battery directly to the PV in. You also want a second way to make sure the panels are disconnected and not loaded when doing maintenance.

Well, if you have a fire at your home, and the insurance investigators figure it out, that DC breaker will look like a real bargain! On inverters with a DC breaker (like the popular SunSynk/Deye/GoodWe models), you only need to fuse the panels, the breaker on the inverter is sufficient if mounted at the correct height.

You will make fire every time you open the AC breaker under load, not just after 3 years. I think all the other times you were just lucky and the string was not under load.

The inverter overload protection should prevent it from getting fried, but I don't think there is a way that you could start a 7.5kW induction motor with 2x12kW Sunsynks. Induction motors are not forgiving, and the (5 to 7)x rule will still apply, and the batteries also need to be able to cater for the surge. VSD is by far the best solution, soft starters are not very kind to inverters.

This is the way. You could even go for a single phase inverter like the Sunsynk 16kW then.

And every single one (in SA) is configured to count both export and import as "use" - that is if it's not configured to go into tamper mode on export.

None of your issues are the earth/neutral bond's fault. That said, it still has to be fixed to meet code.

Looks like the burgundy cap to me.

https://www.solarpowerworldonline.com/2014/02/dual-mppt-defined-understanding-mppt/

Of course there is. It's the limit set by the BMS. If that limit is so high that it shortens your battery life - then that is a battery design flaw.

Don't do that. The newer firmware does not have the high DC injection issue (aside from the fact that it is only an issue when connected to the grid). If you change to 50Hz grid default, you disable some of the safety features, and your inverter is not NRS-097 compliant anymore.

It's probably a cloud, which causes production to drop below load, causing a battery mode switch from charging to discharging, which will cause it to stay in that mode for a while. The best policy is not to worry about it.

Have you tried shouting at the clouds?

Well, then I can inform you of the next trick - swapping out one of the soldering irons for hot air works even better...

Units like these don't have ways to limit it to a single room, apart from getting a ladder and adjusting all the vents.