Crossy

You match your DC suppressor voltage to the system voltage. I would go for a suppressor of system maximum voltage +15 to +30%. AC suppressors should be 275V working. Surge suppression is one of those things you don't need, until you do! With a hybrid inverter worth 45k Baht I'm happy spending a few k on surge suppression. And ours have definitely triggered to the point that they wore enough for the inverter to complain about earth leakage.

Yup, that should work. The worst that can happen is it won't. The amount etc should be filled automagically.

To pay via the app you enter the BB reference number as that's what links your Lazada transaction to the bank system (it was generated by the bank and sent to Lazada). If you put the wrong number the system will tell you anyway.

You'll probably find that the default settings are Solar => Battery => Grid (so you switch to grid when the batteries reach a specific state of charge). Did your meter actually run backwards (do check that the numbers also count down)?

I'm not sure "firebrand" is particularly appropriate language at this juncture

Yes, but do ensure you place breakers and fuses where the installation manual says.

Yup ^^^, and smart-phones just make things worse. Do not get me started on the motorcyclists and bicyclists! I've only actually hit one cyclist (going the wrong way, in the dark, no lights), but I've scared myself way too often coming up behind motorcycles in the dark, dressed all in black without even a functional reflector, bumbling along at 20kph in the centre of the lane. It's almost as if they want to be hit.

The shower type are intended to operate with the outlet open (shower head only), so if it all goes wrong and the heater boils it vents though the open head, so no need for a safety blow off in the heater to stop it blowing up, less $$$. Many will actually function just fine with a tap on the outlet, but they are missing that vital safety device.

I wouldn't go much over 90% of the maximum input voltage of the MPPT, 10 panels would be 455V nicely in the green. Definitely 500.5V on a max rated input of 500V would be classed as "unwise", it might be OK or it might go fzzzt on a cool morning when the panels are generating just a smidge more oomph. The problem is the panels come up to voltage very quickly when it gets light but there's not much energy available so the inverter doesn't do much leaving the full Voc on the inputs.

Noooooo! RIP Sandy ????

OK 4mm2 is good for a 32A (stretch to 40A) breaker so flat out 7kW or so. Your 12000 BTU A/C will pull about 1,200W or 5.5A when at full chat. Assuming there's a good splice (crimped, not just twist and tape) you could safely hang a 6kW water heater on there with no issues. NOTE:- Although 32A is over-size for 2.5mm2 cable there's no possibility of overload as it has a fixed load on the end. UK wiring regs would permit provided a short at the end of the 2.5 would open the breaker (it will be fine unless that's a loooong bit of 2.5)

You could just hook both to the A/C line, the breaker, if appropriately sized of course, would protect the cable. I'd actually lay odds that it would never actually open even with both on together. Not really good practice but ... What size cable and breaker go to the A/C?

Yeah, they are a sort of local MPPT. I have zero experience of the beasts so can't really comment on just how well they work.

Yeah, they go under the panel, you need one per panel ???? Although I understand that you only need to put them on panels that get shaded ???? If you have space it's cheaper to add more panels.

... and how he can extract as much $$$ as possible.

Going with half-cut panels can also improve your shading performance as can panel optimisers. Of course the best solution is to avoid shading ???? EDIT https://www.staticelectrics.com.au/electricians-blog/how-do-solar-panel-optimisers-work/

I'd definitely ensure you have enough charger for your max storage. EDIT although if you are sure you have enough inverter you can add separate MPPT charge controllers.

With that much storage I think you'll need more charger. So 2 x smaller inverters might be better. Our 50A charger puts around 9kWh into our pack by about 1PM, earlier on a good day. Today's charge profile, a bit dull. .

MPP are a reasonably well-known low-cost brand, not so sure about the Easun. 11.2kW vs 8kW and having two units means that if one fails you still have power. Of course having two units also affects the reliability so there's actually more chance of having a unit fail. If I could get 2 x 5kW MPP units there would be no argument ????

I still recommend that you get sufficient inverter power for your "ultimate" configuration even if you don't have all your panels and storage (the expensive bit) yet. At least then you know that your inverters will indeed run in parallel. There's no guarantee that a future version of the same unit will pair with your existing one.

With all these problems, there's an easy way and a hard way. The easy way is a small tank heater with a 1.5kW element plumbed into the existing cold supply and powered from a regular outlet. All modern tank heaters have the relevant safety devices built in so it's not a complex task. Once it's heated up you have enough hot water to do the washing up. Then it re-heats fairly slowly until you need more hot water. QED

You should keep the string voltage as high as possible without going over the limits. I think what you are suggesting is just fine and you have headroom for a few more panels.

The inverter will limit the input current so if you are a bit over panelled it won't kill anything. It's in input voltage that kills.

25A for a 6S2P arrangement. Don't forget DC surge arrestors on the panel input and AC arrestors on the mains input (put both close to the inverter).

10A is assuming all 12 panels in series (12S). Two sets of 6 series in parallel (6S2P) would be 20A ish. At which point you probably want to go the 4mm2 cable. All our panel strings (9S and 10S) are actually wired in 6mm2 (the biggest that fits in my MC-4 connectors) for minimum volt drop. How you arrange the panels depends upon the inverter MPPT parameters. It is imperative that the Voc (open circuit voltage) of your series panels does not exceed the maximum input voltage of the MPPT, ever!