Where to buy Solarcells

[Tubulat]

On 5/17/2021 at 10:16 AM, JBChiangRai said:

my inverters came from the factory with parallel cards pre-installed although they didn’t set up the DIP switches.

 

You don’t need a separate ATS, here’s how I think it works, the manual is not clear.  The inverter sometimes joins the input and output together and optionally boosts the voltage to sell back to the grid, or it can load match ie solar and/or battery providing power in-sync with the grid but not feed back to the grid, or it can power the output on its own disconnecting from the grid in a power cut or it can join the input and output together in bypass mode if battery empty or no solar.

 

with 2 inverters and assuming they are about 5Kw each, you want cable rated at over 50amps from PEA to inverters and then from inverters to electrical box in the house.  I prefer to leave anything with high current (>10amps) to the experts.

 

With those MUST inverters, if you buy a 2nd battery assembly, you have to wire them both to a bus bar or equivalent and then from the bus bar to each inverter keeping the cable lengths from bus bar to inverter the same.  Ideally, your batteries should be identical with BMS set the same and same length cables to the bus bar.  The inverters will show an error if the cable lengths from bus bar to inverter are different for your two inverters.

 

If you’re using the batteries for power cuts, set the inverter to not charge to a SoC higher than 80-90%, they don’t like to be kept at 100%. If you’re cycling them every day a DoD of no more than 80% and (optionally) 100% if grid power not present (my view is that shortening the life of the batteries by fully discharging in an emergency situation is more important and a highly unlikely scenario with sizable batteries).

 

You can do all the settings without software and a PC. I’ve also fitted a good quality 15/45 spinning meter next to the inverters between PEA and inverters, I just need to make sure that meter has a higher reading on it each month when they come to read the PEA meter 200 meters away outside the (private) Moo Baan.

Thank you very much JB, all your experiences I'll take with me while build the whole stuff together.

Yes, they are 2 times 5.5KW converters, at the moment I  I connect the 2 parallel cards inside.

Waiting for the 270A DC switch, also still I don't have all the solar cells, it takes time.

Only to find  an expert for the high current and connection to the net will not be so easy to find.

[JBChiangRai]

16 hours ago, Tubulat said:

Thank you very much JB, all your experiences I'll take with me while build the whole stuff together.

Yes, they are 2 times 5.5KW converters, at the moment I  I connect the 2 parallel cards inside.

Waiting for the 270A DC switch, also still I don't have all the solar cells, it takes time.

Only to find  an expert for the high current and connection to the net will not be so easy to find.

I don’t have such a high current DC switch, I have 125 amp DC breaker on each battery.  If one trips, all the power will come from the other battery which will more than likely trip as well.

[Tubulat]

On 5/19/2021 at 10:38 AM, JBChiangRai said:

I don’t have such a high current DC switch, I have 125 amp DC breaker on each battery.  If one trips, all the power will come from the other battery which will more than likely trip as well.

I also had doubts before I order this, because the price is more than 2000 thb, but yes, it happens and waiting to get it.

But on the other side, I was thinking by high current like induction cooking, max 6 kW, and together with one or two arcons, I don't like the switch trips because this.

Maybe it will never happens, but still....

[Tubulat]

On 5/14/2021 at 4:08 AM, sezze said:

Did you know that many high power cables these days all over the world use alu instead of copper ?

Also , i did check a calculator to check cable size . It gives me for 40 amps -> 9kW -> 8AWG for copper (10mm2 ) and 6 AWG (16mm2) for alu .

https://www.electricaltechnology.org/2014/04/electrical-wire-cable-size-calculator.html

Nobody is stopping you to buy 25mm2 copper cable , but it is a serious overkill ( it's your money ...) .

Believe it or not, I bought 25 mm square aluminium cable but by accident.

First I was shopping at Watsadu for 25 mm square copper but they don't have.

Yesterday I visit Homepro and search again, and yes they have 25 mm square.

Because I need 4 x 15 mtrs, I bought a 100 mtr bundle for about 115 thb/mtr.

It was not possible to look inside the bundle and was under the assumption it was cupper....unfortunately.

But the problems start with connection to the inverter, this have connection for not bigger than about 15 mm square so I order at Ali some terminal, but still gives problems because it is not possible to solder. Clamping could be the only option but clamping aluminium?

[sezze]

As far as i know , alu can be clamped or rather crimped  , without problem .

[Tronx]

Yes that is the only way to connect it. You will need a good tool that makes gas tight seals.

[Crossy]

Aluminium CAN be soldered, you can get the low melting point "aluminium solder" and special flux from aliBaba, there are also electrical fittings with cage clamps rated for aluminium (if it doesn't say so, it is not, and regular ones WILL work loose over time).

 

None the less, the special Al-Cu fittings @Tubulat shows are likely the easiest, you need a decent crimping tool with the correct size jaws. 

[Tubulat]

The next question is risen about earth connection. (grounding)

Of course the frame of the PV must be connected to earth but I see everywhare also the minus of the batterys and the minus of the PV panels must be earthed.

Anybody a suggestion about this, I can't imagine why I have to earth the battery, after all when you connect the minus from the battery, as well the minus of the PV panel to ground, the minus inputs of the inverter will automatic be grounden so too.

[BritManToo]

17 minutes ago, Tubulat said:

Of course the frame of the PV must be connected to earth

I've never bothered, and all my stuff works perfectly.

[Tubulat]

3 minutes ago, BritManToo said:

I've never bothered, and all my stuff works perfectly.

And you'll never wonder what happens with thunderstorm and lightening?

But maybe for you different, if I remember well you are not connected to the grid?

[BritManToo]

Just now, Tubulat said:

And you'll never wonder what happens with thunderstorm and lightening?

But maybe for you different, if I remember well you are not connected to the grid?

Connecting raised metal items to an earth increases the chance of a lightning strike to the equipment.

 

[Tubulat]

1 minute ago, BritManToo said:

Connecting raised metal items to an earth increases the chance of a lightning strike to the equipment.

 

I can't deny that but.....

[tonray]

On 4/28/2021 at 4:47 PM, Crossy said:

Loads of low-cost panels locally on Lazada or even go to Global and the like.

 

Amorn often have offers if you can visit a store (the website is woefully out of date).

 

Similarly for inverters, on-grid, off-grid and hybrid.

 

 

 

Love Amorn...only place you can buy solar panels, chocolate covered pretzel sticks and garden tools in one visit...as well as a great selection of replacement fan blades and Blender parts...