what's your PV array string voltage ? seeing some up to 400V +

Hello everyone,
I have 17 solar panels, 9 of them running 3s and 3p, the other 8 are 4s and 2p
total voltage is140v and 146v respectively
real world measurement just around 115v - 125v
since these # are less than 150v max that many cheap charger can support and safe to the touch if accident happened
wondering why there're many systems here with 400v, 500v + ?
what're the pros and cons ?
as far I can see, it's very dangerous and cost a lot
so what give ppl ?
understandable if the system is huge, like many hundreds panel or more
good day all,

Mine is a bit over 400v max and the advantages is the wire size. The higher the voltage the less amps are involved moving the same amount of power so smaller wires can be used. BIG advantage when it comes to cabling cost. Normally it means two wires can replace 4, 6, 8 or more needed for multiple strings or just smaller gauge wire needed to make the run from the arrays to the charge controller.

My inverter’s (EG4 6000XP) optimal voltage is 320volts. I’m spec’ing my 16 panels to hit near that voltage, which will be 2 strings of 8s. I also need to keep my VoC below 480volts according to the inverter spec.

I will also keep the amperage down to around 12 amps which allow me to use #10 wire.

Together each string will get me close to the 4kW that my inverters MPPT can accept.

3x 2k solar arrays. 2 at 70v, 1 at 80v.

Array wire runs are short, and wires are oversized for current (#10 carrying 15a). I have shade issues, so all arrays are 2s3(or 4)p to minimize losses.

I have 3x outback fm80 charge controllers. Max voc is 150v. I have a couple conext mppt 80 600 units, but I don't want to string panels in series to achieve the needed voltage to run those charge controllers, I'd lose my shade tolerance.

I have a small 1.3kwp array, so not much choices... Maximum PV voltage (VOC) is around 85v, inverter max is 145v.

I prefer these lower voltage inverters for safety, as some of the higher voltage ones have a known issue of having AC on the PV lines. Quite a few posts on the forum about this issue. Also on Australian AEVA Renewable energy forums.

Also, my inverter (3kw, 24v) is inside the house, so I prefer lower voltage PV coming in for the safety (less arcing compared to 400v). That's also why I preferred to go 24v and not 48v (which with Lifepo4 can exceed 50v DC when fully charged, which is considered dangerous according to local regulations).

I am somewhat limited as to current, since I used 10awg PV wire for a 30 meter run to the inverter. But my inverter can handle 2kw max PV anyways, so I have some headroom to expand.

But seems like most larger inverters go 48v for the battery and around 400v for the PV. I can understand that.

Usually around 700V, but once (sunrise, -35C, snow) witnessed going over 800V (808V) which is max limit for my Deye12K (~SolArk15K). Deye tolerated overvoltage for ~10s and then alerted "PV overvoltage" and clearly did something internally to lower PV voltage (MPPT?). After a minute or two voltage was under 780V IRC and it started working normally and has ever since.

MPPT range is 200-650V according to Deye, so most of the time I'm above it, but clearly MPPT is working just fine. My two Bluesun15K inverters have 1100V max V limit snd they are PV wired the same as my Deyes so they are always in their MPPT range (200-950V). Still they produce less than my Deyes.

Trying to keep voltage up because my array is 100-150m away from my inverters.