roadkill

Hi Guys, My Current Setup: 2 x Luxpower Sna5000, 2 x pylontech us3000c, 18 x JA 460w 3 string Friends Setup who is moving and selling his gear: 1 x luxpower sna5000, 2 x Dyness B3 3.6kw, 4 x Longi 455W I am considering splitting my bank and buying the 2 x Dyness from my friend. Each invertor will then have its own bank and BMS. The down side is both invertors cant charge both banks, but i have 3 strings in total so i should be fine. i know it is not the 'ideal' setup but in my case its cost effective and low risk as i know the batteries are in good condition. What is your opinion on this? I need another 2 batteries to increase my storage, i just dont know if i should stick with pylontech, split my bank and dyness, or move over to another brand completely. Im out of touch with the newer battery brands. My pylons are going on about 3 years now with about 900 cycles. What would you do in my situation if you are on a budget, considering how expensive storage is. I also have a growatt spf5000es collecting dust that my sister was supposed to use but never did when i upgraded to the 2 x sna5000, so i could sell either the sna5000 or that, as my sister needs some solar and i am working on that for her. Thanks in advance

So here is the PV Db as of today, better?

@Superfly So my MCB is oversized. Please excuse me because im about to make a whole bunch of assumptions here as im trying to figure all of this stuff out. Is this correct - My Mppt has an imp of 13A, and the ISC is 20A. in order to protect the invertor i then need to use an MCB and fuses rated at 13A x 125 Percent, which equals 16.25A, closest size to that is 16A. So would it be correct to say my MCB and fuses should be rated at 16A?

I really don't understand those spds either, it has a plus and minus on it, only thing that makes sense to me is that it is single pole and indicates that it can be used on either. So guys here is the debate now, i phoned the ECA and was informed that the correct order is this: PV-MCB-SPD-Fuses-Mppt This is conflicting with some of the info above and the prewired dbs Their Reasons are: Overcurrent protection is required before the SPD - fuses or MCB can do this, but should a fuse blow, the disconnect MCB is supposed to be before the fuse so that the fuse can be safely changed. then it makes me ponder if the 63A rating of these breakers is too high. Also the earth running from the panels to the SPD needed to connect to an earth bar, the earth coming out of the SPD should be no longer than 50cm as per SANS, and all earth's shall be bonded.

So electrician came back and fixed it. not sure why he took out my double pole Onesto spd and put in a single pole spd. Is it recommended to use a double pole spd?

@TaliaB they dropped off the coc today, I also organised for an electrician to come around to check for me but he didn't pitch. The install was gone 2.5 weeks ago. Ideally just 1 correctly rated breaker would be better for me as I plan to put 3 strings in that dB box and with fused as well as SPD it won't all fit

@Superfly Ah thanks that makes sense, so my PV is single string so about 9.45 imp and 10.85 isc, these fuses in the db are 32a but not sure if they are the right fuses? So DC breaker of about 15-20a be fine with 600v rating? Depending on what comes in those sizes I need to check what's available, that way it trips before fuses pop Something like this:? https://www.solar-europe.co.za/product/etek-dc-2p-mini-circuit-breaker-20a-6ka-500vdc-ekm1-63dc-220/

@Superfly thanks for the info, I'm going to get someone to come check it

@Superfly he removed this breaker because he said it was an AC breaker not a DC

@Superfly I wasn't quite happy with the install, so trying to figure out everything that is not complaint so I can take it up with them

@Superflyhow should this have been wired? Where is the spd earth supposed to connect to? He took out my beny 600v dc double pole breaker and put that single five-star in because he said the beny was an AC breaker, I didn't know any better but googled the part and it is a DC breaker. They told me the panels needed an earth wire to the dB board and ran one

@Superfly they coming to drop off the coc for this job this week

@Modina Solar voltage is about 400V, 9x ja 455w panels

@PowerUser Lux sna5000, Max voc on that invertor mppt 480. Voltage range 115-385 or something close to that

@Superfly @JustinSchoeman So the PV string positive and negative are coming in to the surge arrestor from the top (from the panels both positive and negative are black cables, this was the first installers work) the top left red cable is the positive going to the invertor. The negative is just joined on the surge arrestor to invertor. The earth wire goes to the panels