It seems there are people that advocate switches breakers fuses between every component of a solar system

BELT AND BRACES

For instance do I need a combiner between panels and inverter or is the attched setup good enough?

 

Right. So you must have some kind of DC protection. Imagine something goes wrong (you'd probably need two things to go wrong) and battery power flows backwards to the solar panels, then you want something to blow before the cables glow red hot and the house goes up in flames. So you must have a fuse or a breaker in your PV line. About 100 amps is all it takes to make a 4mm solar cable seriously hot. Don't ask...

YOou need a fuse in at least one side (positive or negative, though I really prefer both sides, because cables running from roofs and the possibility of two earth faults is a real possibility... but on a camping rig just one fuse would be fine).

Also, rules says PV strings must be individually fused, but we've discussed this before: For only two strings this usually does nothing. So if you at least have fuses in the main PV wires you should be good, but you've got to have at least that.

In fact, if you have to save costs at all costs (which I am not advocating... but if you must), spend money on fuses and drop the DC disconnect. The fuses can serve as a disconnection point and at least gives you protection. The switch does not.

Now for the most important one: You must have a fuse in at least one wire coming from the batteries. Believe me, I have accidentally shorted a Pylontech module. The BMS will disconnect... but quite possibly only after you started a fire. In my case I only mildly damaged a scope probe... the battery did not switch off.

So the bare minimum you need is at least one fuse in the PV line, and at least one fuse in the battery line. Bare minimum. It probably won't pass a proper inspection, but it's at least something.

I'm sorry, "saving" costs on the DC side is never ever a cost saving. Trust me on this one. 

Have fuses and breakers - they are dirt cheap compared to everything else.

Thanks  Plonkster and TTT, for me your quick and informed replies is as we say "''n riem onder die hart" .. thanks.

Is the combiner plugs acceptable to tie the strings together?

What about crimping lugs to cables this also seem quite critical ... special tools?

 

7 minutes ago, JohanG said:

What about crimping lugs to cables this also seem quite critical ... special tools?

Buy the cable from someone with a crimper. They will usually crimp the lugs for free. It does mean you need to carefully measure how much cable you need of course. I did this for years before I finally found a crimper in the sort of price class I was willing to pay. On my first install I even had them crimp the MC4s on to the ends of the solar cable (well, it was Tyco connectors back then). You really can get away without a lot of the expensive tools.

Once you do buy tools, I would also advise investing in good quality cable shears. Can't cut it with a side-cutter. You can hack it off with a hacksaw, but you're never getting it into the lug if you do that... 🙂

22 hours ago, plonkster said:

Right. So you must have some kind of DC protection. Imagine something goes wrong (you'd probably need two things to go wrong) and battery power flows backwards to the solar panels, then you want something to blow before the cables glow red hot and the house goes up in flames. So you must have a fuse or a breaker in your PV line. About 100 amps is all it takes to make a 4mm solar cable seriously hot. Don't ask...

YOou need a fuse in at least one side (positive or negative, though I really prefer both sides, because cables running from roofs and the possibility of two earth faults is a real possibility... but on a camping rig just one fuse would be fine).

Also, rules says PV strings must be individually fused, but we've discussed this before: For only two strings this usually does nothing. So if you at least have fuses in the main PV wires you should be good, but you've got to have at least that.

In fact, if you have to save costs at all costs (which I am not advocating... but if you must), spend money on fuses and drop the DC disconnect. The fuses can serve as a disconnection point and at least gives you protection. The switch does not.

Now for the most important one: You must have a fuse in at least one wire coming from the batteries. Believe me, I have accidentally shorted a Pylontech module. The BMS will disconnect... but quite possibly only after you started a fire. In my case I only mildly damaged a scope probe... the battery did not switch off.

So the bare minimum you need is at least one fuse in the PV line, and at least one fuse in the battery line. Bare minimum. It probably won't pass a proper inspection, but it's at least something.

What about the SeganSolar combiner box?

Seems quite pricy

 

https://shop.bundupower.com/shop/solar/protection/dcb-f12a-2i-600v-i32a-i_ii-1o/

Protection

600V Combiner Box 2 Inputs 1 Outputs 32A Isolator Type I_II SPD

Availability: 

In stock

---

 

600V Combiner Box 2 Inputs 1 Outputs 32A Isolator Type I_II SPD

R6,719.67

1 hour ago, JohanG said:

Seems quite pricey.

Jip, they all are. If you buy the parts and put it all together yourself, it is cheaper.

8 minutes ago, The Terrible Triplett said:

Jip, they all are. If you buy the parts and put it all together yourself, it is cheaper.

Mmmh. I'm just thinking out loud here. Those are Dehn surge protectors. Not the cheapest. If you go for Citel, you're still around R900. There's two in there, so that's R1800.

DC rated breakers, double pole, around R300. Again there are two, so R600.

A decent case that's waterproof, probably something like R700 (googling around a bit).

MC4 panel connectors, R35 a piece, so R140.

So that's R3300 give or take before labour. And don't forget the stickers.

Just now, plonkster said:

So that's R3300 give or take before labour.

This time, I did not point it out. 🤣

On 2019/05/22 at 9:27 AM, plonkster said:

Mmmh. I'm just thinking out loud here. Those are Dehn surge protectors. Not the cheapest. If you go for Citel, you're still around R900. There's two in there, so that's R1800.

DC rated breakers, double pole, around R300. Again there are two, so R600.

A decent case that's waterproof, probably something like R700 (googling around a bit).

MC4 panel connectors, R35 a piece, so R140.

So that's R3300 give or take before labour. And don't forget the stickers.

Getting back th the subject of combiner boxesOn Amazon they sell an EchoWorthy 

Solar combiner box with breakers:

The PV combiner box is suitable for photovoltaic grid-connected and off-grid power generation systems. Its main function is to converge the input of PV array.
It has three protection measures：
1. The PV combiner box is configured with photovoltaic dedicated high-voltage lightning arrester, DC fuse and circuit breaker to provide short circuit fault protection and lightning protection.
2. It has protected function of over-voltage and over-current so as to avoid damage to photovoltaic panels and inverters when the fault occurs.
3. The PV combiner box is also used to reduce the connection of the photovoltaic array to the inverter, optimize the system structure, improve the reliability and maintainability of the system, make the photovoltaic system at its best.
Features
1. Multiple photovoltaic array input, maximum current of a single array input is 10A.
2. The single photovoltaic array is configured with a high voltage fuse which has over-voltage and over-current protection.
3. Photovoltaic dedicated high-voltage lightning arrester. Both positive and negative poles have lightning protection.
4. Photovoltaic dedicated high-voltage circuit breaker control output, providing short-circuit fault protection, safe and reliable.
5. Meet outdoor installation requirements. Protection class is IP65.

for about R2500 ( not available for ZA)

See images

Is it possible to identify the components for me?

Can one make up the same locally?

Will it do the job?