6000xp Panel configuration

[dpdbax10]

Ok, I have my 6000xp all set up and seems to be running good.
I just ordered some panels. I know it's close to limit but does it look like I can put all of these into 1 mppt? If so, all in series ok? I ordered 10 of the 395 watt bifacial. Want all in 1 mppt I hope.

 

[sunshine_eggo]

There are several panels listed on that datasheet.

Your string Voc must be under the max MPPT voltage limit AND allow for cold temperature margin.

PV array temperature correction table (NEC 2017)

There are calculators like this one made by @upnorthandpersonal which help you calculate PV array voltage and power for low temperatures based on the specific specifications of your panels. These are great tools and will give more precise...

diysolarforum.com

check your regional record low and apply the suitable correction factor above. Let's say your record low is -25°F . You would need to take your array series Voc and multiply it by 1.23. This value must be under your MPPT Voltage limit.

 

[MichaelK]

I threw the parameters for your panels into Midnight's string calculator and see that for SSE's example of -25F above, your Voc might go as high as 434V, just slightly lower than the table's prediction of ~455V. So, except for some strange freak-weather event, your 10 panel string is likely to be OK.

But, be extremely careful working around DC voltages that high. That's at about the voltage that can pass through dry skin, and very likely to be lethal.

 

[dpdbax10]

I threw the parameters for your panels into Midnight's string calculator and see that for SSE's example of -25F above, your Voc might go as high as 434V, just slightly lower than the table's prediction of ~455V. So, except for some strange freak-weather event, your 10 panel string is likely to be OK.

But, be extremely careful working around DC voltages that high. That's at about the voltage that can pass through dry skin, and very likely to be lethal.

View attachment 206059

Wow. Thanks for doing that guys. I looked at the record lows for that area it was -31f. But typically I would say -15f would be season low at the normal extreme.

Although I prefer to do it in series. Would 2 sets of 5 in series and then parallel together be a better option?

 

[sunshine_eggo]

Wow. Thanks for doing that guys. I looked at the record lows for that area it was -31f. But typically I would say -15f would be season low at the normal extreme.

Although I prefer to do it in series. Would 2 sets of 5 in series and then parallel together be a better option?

Best to use record low.

The -.304%/°C Temperature coefficient is MORE favorable than the NEC charts predict.

10S of those panels will stay under 450V until you're at -45°F/-43°C .

 

[ChrisSwolls]

Wow. Thanks for doing that guys. I looked at the record lows for that area it was -31f. But typically I would say -15f would be season low at the normal extreme.

Although I prefer to do it in series. Would 2 sets of 5 in series and then parallel together be a better option?

Im in the same boat right now, setting up new strings. Our record low is like -31*F but that was also in the dead of night with 0 PV input.

I have 15 of the ZN 370M panels and I’m debating running a string of 10 and another string of 5, facing more easternly to grab more morning sun.

You can get by with the 10 but based on where you are, does it make sense to split into different strings to catch earlier sun and later sun? Based on the numbers though your VMP might be lower than you’re wanting.

 

[dpdbax10]

Im in the same boat right now, setting up new strings. Our record low is like -31*F but that was also in the dead of night with 0 PV input.

I have 15 of the ZN 370M panels and I’m debating running a string of 10 and another string of 5, facing more easternly to grab more morning sun.

You can get by with the 10 but based on where you are, does it make sense to split into different strings to catch earlier sun and later sun? Based on the numbers though your VMP might be lower than you’re wanting.

Hmm. It might make sense to split them into morning and evening sun. I really hadn't given that much thought.
On my other mppt on the 6000xp I have 24 -100 watt panels . In 2 series of 12. 12 on a tracker and 12 facing south and paralleled together.
I'm still learning and experimenting I guess. I have probably way more them enough for summer as far as input. My biggest concern is winter when the snow covers them. It's at a location that I'm not at for weeks at a time. But I have cameras and internet running 24/7 Completely off grid. It has very little draw .
But on those days the sun pops out I really need the batteries to charge to get me through the stretches I get Nothing. Although I don't know what to expect.