Please Could double check this for me Victron RS 450/100

[Zapper77]

Well darn, I think you're right.
I just found the victron calculator and it looks like each mppt can output up to 80a but the total output is off course limited to 100a.

It also says only 10s is possible

View attachment 174022

You may have issues with heat if you push that many amps through a single mppt. Manual included an Asterix and warned that heat would cause throttling.

 

[1201]

You may have issues with heat if you push that many amps through a single mppt. Manual included an Asterix and warned that heat would cause throttling.

The calculator output actually said it's undersized, and given it can handle up to 7200w per mppt (360v *20a) I think it should be fine.

Now I just need to decide if the 450/200 or the midnite barcelona will serve me better. With barcelona I can do 2 strings of 14s, with 450 200 I can do three strings of 10s,

 

[sunshine_eggo]

Here on this forum.I can see how it can be inferred from the specs.


Nope never. I've seen 4f but 11s at 404v leaves enough headroom for 4f

32°F is freezing. 4°F is WELL below freezing.

I don't have your panel's exact Voc temp coefficient, but you have a 45/405 = 11.1% margin.

Using a conservative -0.04%/°C puts you at -2.7°C or 27.14°F.

4°F is well below 27.14°F.

Additionally, NEC requires:


an 18% margin for 4°F or

at 4°F your 404V array will be 404 * 1.18 = 476.72V - a bit over 450V

I recommend you revisit if 11S is really okay.

EDIT: I see -.26%/°C - that's pretty darn low. YOu should be good down to 1.4°F

 

[1201]

32°F is freezing. 4°F is WELL below freezing.

I don't have your panel's exact Voc temp coefficient, but you have a 45/405 = 11.1% margin.

Using a conservative -0.04%/°C puts you at -2.7°C or 27.14°F.

4°F is well below 27.14°F.

Additionally, NEC requires:

View attachment 174024
an 18% margin for 4°F or

at 4°F your 404V array will be 404 * 1.18 = 476.72V - a bit over 450V

I recommend you revisit if 11S is really okay.

EDIT: I see -.26%/°C - that's pretty darn low. YOu should be good down to 1.4°F

Yeah, the calculator said 11s would be too much so I dropped it to 10s.i don't know why I had read your original message as below zero, when it was clearly below freezing.

Funny enough The midnite calculator says 11s at 4f is 447.7v but the victron calculator says 468.8, same exact numbers inputed. -.26%/ degree c