Setting up 5.1 kw off grid

[Island solar]

Hi all!
I have 20 255 watt 8.39 Imp 30.4 Vmp 37.5 Voc panels, 2 Tristar 60 amp PVM controlers, 16 T105 golf cart batteries and a Magnum 4048 (4kw, 48 volts dc) inverter.

To be honest, large solar systems are new to me question is:
Since the controlers are pvm, it's my understanding (I could have interpreted it wrong) to make the voltage input as close to the output to increase efficiency?

Will 10 banks of 2 panels (60.8 Vmp) each
Be enough voltage to bulk charge a 48vdc battery bank?
If I had MPPT controlers, I would go with
If not, please state your suggestion!

 

[MisterSandals]

Since you have the ability to run 2 arrays and 2 controllers side by side, give it a go.

Array 1: 2s2p
Array 2: 4s

This would be a learning moment for all of us.

 

[onemorebattery]

The manual has some seemingly conflicting specifications.

I would run 2s5p per controller. I would not exceed 2s nor 6p per charge controller.

That will be enough to bulk charge the T-105 batteries in a 8s2p 48 volt setup. The time of charge depends on the amount of solar production at the installed location but your setup will easily recharge from a 50% state of charge back to full on a good sunny day.

Do not connect a solar input greater than a nominal 48V array for battery
charging. Never exceed a Voc (open-circuit voltage) of 125V.

• Max. solar array Voc 125 V
• Max. operating voltage 68 V

• Current ratings — Solar Input
TS-45: 45 A
TS-60/M: 60 A •

Current ratings — Battery Charge Control
TS-45: 45 A
TS-60/M: 60 A

 

[Steve_S]

There are TWO types of Triststar 60A controllers, MPPT and PWM. They have different features & functions and abilities. Both are Good Products !

They have a String Selection tool which you put in the Solar Panel data, your target SCC and play with various layouts / configs for optimal results.

String Calculator - Morningstar Corporation

+

string-calculator.morningstarcorp.com

TS-60 PWM Manual : https://2n1s7w3qw84d2ysnx3ia2bct-wp...uploads/2014/02/TriStar-Datasheet-English.pdf
NOTE: Max Solar Input Voltage is 125VDC

 

[onemorebattery]

There are TWO types of Triststar 60A controllers, MPPT and PWM. They have different features & functions and abilities. Both are Good Products !

They have a String Selection tool which you put in the Solar Panel data, your target SCC and play with various layouts / configs for optimal results.

Unfortunately the String Selection Tool will not calculate for 48 volt systems on the TS-60 even though the spec sheet says that model will do 48 volt systems except with very low voltage panels. The TS-60 is bordering on unusable for the panels that OP has.

 

[Island solar]

Unfortunately the String Selection Tool will not calculate for 48 volt systems on the TS-60 even though the spec sheet says that model will do 48 volt systems except with very low voltage panels. The TS-60 is bordering on unusable for the panels that OP has.

That is what I'm afraid of, that the pv voltage output including voltage drop was bordering acceptable the PVM controlers input.
I suppose I could experiment, I was hoping for a answer either way so I could just put it together.

 

[Steve_S]

I know of people using the Tristar MPPT controllers and they just love them, there is a lot to like with their SCC's, no doubt about it, but as for the PWM stuff from them I honestly can't remember anyone talking about them. Considering the advantages of MPPT and the ability to handle large capacity panels, which are cheaper per watt, only makes sense to support that.

The TS-MPPT-60 & TS-MPPT-60M still only accept Maximum PV Open Circuit Voltage 150 volts DC.
REFS : TS-60 Brochure PDF TS-MPPT-Operators-Manual.pdf
Also, I didn't see anything in regards to using / linking multiple SCC's up in their docs.

This is where the conundrum begins, if you need new SCC's there's a lot of options to make your head spin and overload with information on.
You have 20x 255 watt, 8.39 Imp 30.4 Vmp 37.5 Voc panels, You can do a lot with that !

I have 8x 260W, setup as 2 Strings of 4, I see 1800-1900W & 190 +/- Volts from that on a nice sunny day. My Classic 200 does push out up to 79A for my 24V battery bank. Which is in transition from 856AH FLA to 910AH LFP. Adding more solar & linked controller because I run short in mid winter.

 

[Island solar]

There are TWO types of Triststar 60A controllers, MPPT and PWM. They have different features & functions and abilities. Both are Good Products !

They have a String Selection tool which you put in the Solar Panel data, your target SCC and play with various layouts / configs for optimal results.

String Calculator - Morningstar Corporation

+

string-calculator.morningstarcorp.com

TS-60 PWM Manual : https://2n1s7w3qw84d2ysnx3ia2bct-wp...uploads/2014/02/TriStar-Datasheet-English.pdf
NOTE: Max Solar Input Voltage is 125VDC

 

[Island solar]

Yes it is shown as marginal on its own 2 panel suggestion.
I wonder why it doesn't show a 3 panel configuration ?

 

[onemorebattery]

That is what I'm afraid of, that the pv voltage output including voltage drop was bordering acceptable the PVM controlers input.
I suppose I could experiment, I was hoping for a answer either way so I could just put it together.

I think you'd be OK with a 2s5p setup. I haven't done parallel controllers with that particular controller but I think you'll be OK with that too. Match the charge profiles.

More info.

Guide to Parallel Charging Using Multiple Charge Controllers

Large off-grid systems may require greater charging than one controller can provide. Multiple charge controllers in parallel can be connected to meet requirements.

www.morningstarcorp.com

 

[Island solar]

I think you'd be OK with a 2s5p setup. I haven't done parallel controllers with that particular controller but I think you'll be OK with that too. Match the charge profiles.

More info.

Guide to Parallel Charging Using Multiple Charge Controllers

Large off-grid systems may require greater charging than one controller can provide. Multiple charge controllers in parallel can be connected to meet requirements.

www.morningstarcorp.com

[ICODE,, [/ICODE]
This is new to me,does that mean 2 strings, 5 panels?
Or am I not understanding.
I'm a electrician, but new to large solar systems.

The max input voltage is 150volts

 

[Island solar]

[ICODE,, [/ICODE]
This is new to me,does that mean 2 strings, 5 panels?
Or am I not understanding.
I'm a electrician, but new to large solar systems.

The max input voltage is 150volts

open circuit is 37volts

 

[MisterSandals]

open circuit is 37volts

Then you are limited to 3 in series for each string. At 111 volts this will be your optimal setup.
When you start combining strings, your amps will really add up fast. With increased amps, especially for longer distances, the size of the wire necessary will increase significantly, you'll learn about this next.

 

[onemorebattery]

This is new to me,does that mean 2 strings, 5 panels?
Or am I not understanding.
I'm a electrician, but new to large solar systems.

The max input voltage is 150volts

By 2s5p I mean 2 panels in series and five of those series sets in parallel.

You'll need 10 gauge from each pair to a PV combiner and 4 gauge (THHN ) to the charge controller. Ideally you would position the combiner closest to the charge controller.

 

[Island solar]

Then you are limited to 3 in series for each string. At 111 volts this will be your optimal setup.
When you start combining strings, your amps will really add up fast. With increased amps, especially for longer distances, the size of the wire necessary will increase significantly, you'll learn about this next.

It is my understanding that to maximize the low efficiency of PWM controlers, to get the input voltage close to the intended output voltage.
Anything above that is unused, wasted. That's where MPPT shines!
I am very aware of voltage drop/line loss, I am a marine electrician (with little large solar system knowledge). It seems I'm a couple volts shy concidering my hot, humid location!
I can't thow away 30% of my amps to accommodate a couple $200 contrlers

Then you are limited to 3 in series for each string. At 111 volts this will be your optimal setup.
When you start combining strings, your amps will really add up fast. With increased amps, especially for longer distances, the size of the wire necessary will increase significantly, you'll learn about this next.

 

[tictag]

It is my understanding that to maximize the low efficiency of PWM controlers, to get the input voltage close to the intended output voltage.

It doesn't matter what the input voltage is (well, so long as it's higher than the battery voltage) because the moment you connect a PWM SCC to a battery, the array will be dragged down to the battery voltage, plus any volt-drop across cables/connectors etc. I hadn't considered this before (PWM SCCs don't often cross my mind in the same way laser disks don't) but I guess that means there is no point connecting panels in series at all if using a PWM charge controller.

 

[Island solar]

Well, in this case, at least I need at least 2 in series for my 48vdc battery bank as the nominal voltage I'd 30.4vdc.