SMA Sunny Boy 5.0 - 3 dc inputs (A, B & C) with 3 mpp inputs

[road glide]

If the 1st DC string (A) (10 - 320 watt panels 46.4 Voc & 37.4 Vmp) energizes the inverter, can (B & C) be 5 panels each of 320 watt panels and the inverter will still come on, even if B & C are slightly under needed voltage?
Another words, as long as 1 DC input is hitting the requirements the other 2 (B&C) will come on and be recognized. Total modules 20 Jinko 320 watts.
Inverter coming sometime next week

 

[gnubie]

If it's a 3 tracker model each MPPT acts independantly of the others and can be operating at different voltages on the PV input. The voltage on any given array must meet the minimum though, ie, if the MPPT requires 50V to start (made up figure) and your array is only capable of 40V it will not start.

Keep in mind that solar panels rise up to their full voltage in low light, with no load. So long as you have sufficient panels in series to add up to bring the array within the MPPT's voltage range it will work.

 

[road glide]

If it's a 3 tracker model each MPPT acts independantly of the others and can be operating at different voltages on the PV input. The voltage on any given array must meet the minimum though, ie, if the MPPT requires 50V to start (made up figure) and your array is only capable of 40V it will not start.

Keep in mind that solar panels rise up to their full voltage in low light, with no load. So long as you have sufficient panels in series to add up to bring the array within the MPPT's voltage range it will work.

The 1st string DC input A is way more than enough to bring the MPP up...10 panels at 320 watts (37 to 46 volts) so it is up and running. If want to add 5 more panels or even 10 more, I will wire in a combiner box with 3- 20 amp breakers to control what goes into the inverter.
TO clarify: 10 panels will always be up and running...I want the option to kick up the energy production....10 -15 and ultimately 20 panels when demand is high. 20 panels = 6400 watts

 

[Hedges]

Which model Sunny Boy is this?

SB5.0-1SP-US-41 has 3 MPPT inputs, 220 V to 480 V or MPPT range 100 V to 550 V which doesn't appear to be a problem, but maybe on a hot day the 5 panel strings could drop below 220V and not start operation. Using 6 per string would be good. So use 8, 6, 6.

SB 5000US has narrower PV in voltage 250 V … 600 V which is where your concern would come from, but I think only one MPPT input.

"I will wire in a combiner box with 3- 20 amp breakers to control what goes into the inverter."
?? Why try to control anything ?? Just let Sunny Boy have all the panels and do its thing.

 

[gnubie]

The 1st string DC input A is way more than enough to bring the MPP up...10 panels at 320 watts (37 to 46 volts) so it is up and running. If want to add 5 more panels or even 10 more, I will wire in a combiner box with 3- 20 amp breakers to control what goes into the inverter.
TO clarify: 10 panels will always be up and running...I want the option to kick up the energy production....10 -15 and ultimately 20 panels when demand is high. 20 panels = 6400 watts

If it has 3 separate trackers they operate independently. It wouldn't matter what any given tracker is doing, if another tracker has voltage within it's operating range it will start. If it does not have voltage within its operating range it will not start.

 

[road glide]

Which model Sunny Boy is this?

SB5.0-1SP-US-41 has 3 MPPT inputs, 220 V to 480 V or MPPT range 100 V to 550 V which doesn't appear to be a problem, but maybe on a hot day the 5 panel strings could drop below 220V and not start operation. Using 6 per string would be good. So use 8, 6, 6.

SB 5000US has narrower PV in voltage 250 V … 600 V which is where your concern would come from, but I think only one MPPT input.

"I will wire in a combiner box with 3- 20 amp breakers to control what goes into the inverter."
?? Why try to control anything ?? Just let Sunny Boy have all the panels and do its thing.

It's the SB5.0-1SP-US-41 has 3 MPPT inputs, 220 V to 480 V...Haven't got it in my hands yet,.next week....trying to do my homework now. Duh...hadn't thought of 8-6-6...
So your saying EACH string independently has to meet the parameters...Ok got it....(Kinda like 3 sisters going out on dates with 3 separate guys)
And to be clear, I'm not looking to add more equipment, just curious. I one of those need to know fellows.....
I anxious to see what happens after it's commissioned and up and running...

If it has 3 separate trackers they operate independently. It wouldn't matter what any given tracker is doing, if another tracker has voltage within it's operating range it will start. If it does not have voltage within its operating range it will not start.

Got it...thanks

 

[Hedges]

Are you using this for grid-tie, or are you going to set it up in a battery-backup system?

Why do you "want the option to kick up the energy production" instead of just letting it make all the power it can?
"6400 watts" - you can over-panel well beyond that, especially with multiple orientations since they won't all put out peak power at the same time.

 

[road glide]

Grid tie...one vendor stated that this new 41 would be compatible with grid tie or off grid, that would be nice for the future.
Another said you can grid manage this new unit from 0-100% grid feed....in that case I would wire 2 DC strings at 10 & 10 but I like your suggestion of 8-6-6 because I've read with string inverters as opposed to microinverters if a panel stops producing easier to test with micro inverters, so with 8-6-6 would still have significant energy production....
Again, don't have it in front of me. I do have the OM downloaded. 75 pages English

 

[Hedges]

Grid tie...one vendor stated that this new 41 would be compatible with grid tie of off grid, that would be nice for the future.
Again, don't have it in front of me. I do have the OM downloaded. 75 pages English

Yes, the -41 is compatible with latest codes (grid-support, module-level shutdown if you add a box per panel)

It is officially supported with Sunny Boy Storage, a 400V battery inverter compatible with a couple brands of lithium battery. For that to provide backup and not just peak-shaving, it also needs Automatic Backup Unit, a disconnect switch.

It also works off-grid with Sunny Island. Officially, only grid-tie or off-grid but not grid-backup because it doesn't have the RS-485 link used by SI 6048US. Possibly it will work with the 6.0H/8.0H that are only in Europe at this time, might come to the US later. SMA has emailed me saying that it can be used with 6048US for grid backup by setting it to island mode, because 6048US provides the UL1741 anti-islanding function. That contradicts why they publish, so ask them directly and print out a copy of their response for CYA if you decide to do that.

I'm using earlier model Sunny Boys.

Assuming you don't have to use "rapid shutdown" which is module-level shutdown, the feature of manual transfer to "secure power" direct from PV without batteries should tide you over until you really feel like spending big bucks.

 

[road glide]

Ground mount rack so rapid shutdown not necessary.
Thank you for taking the time for me (a newbie)