wiring 8kw array to 5kw Mppsolar inverter 48v

kakarot

What is the best way to wire 8 mono ( 500 watts each)

Panel specs:

8 x 500 watts. I purchased 10 but 2 broke on the way

Here are the specs from the back of the panels.

pm 500w

vmp 48.63v

Imp 10.28A

Voc 59.01v

Isc 10.87A

Maximum system voltage 1000v

Maximum series fuse rating 20A

I need to wire them to my inverter/charger

http://www.mppsolar.com/v3/catalogs/PIP-MS_MG.pdf

Max AMP is 80A

Max voltage is 450v

I'm not sure if I should wire  the 8x 500 watts panels in series or parallel

All 8 in series = 472.08V ( inverter limit 450v)

All 8 in parallel= 86.96 Amp ( inverter limit 80A)

Mix parallel and series option

6 in series and two in parallel = 354.06 v at 21.74A

4 in series and 4 in parallel =   236V  at  43.48A

2 in series and 6 parallel= 118.02v at 65.22A

battery setup is 12 x 110amp in 3 banks  of 48v config

330A at 48v

What is the best way to wire the panels?

Any tips would help.

mike95490

Any panels wired in series, need to be aimed at the same angle at the sun.  

If you put 4 in series and aimed SE, and paralleled with the other 4 in series aimed SW, you just might improve the harvest over all due south.

kakarot

I'm in the tropics so it doesn't really matter. I have them flat and get 10-12 hrs of sunlight

mike95490

kakarot said:

I'm in the tropics so it doesn't really matter. I have them flat and get 10-12 hrs of sunlight

And you will only get 6 or 7 hours of harvest.  When the sun is at a low angle, a lot of power is not harvestable.

Photowhit

A few things, First 8 - 500 watt panels makes an array of 4000 watts.
I've been helping someone on another forum with this inverter/charger/ all in one thing. It has one input for solar, so you will need to present 1 voltage. It has an input voltage range of 120-450 volts;



So the only way to use all 8 panels is in 2 strings of 4 panels each. I doubt in the tropics if they will ever come close to 80 amps output. Likely closer to 65. Look for your solar panels NOCT value in the manual.

Photowhit

Sorry, I thought you had a link to the manual, I still had it open from helping the other guy. Here's a link to the manual where I got the info;

http://www.mppsolar.com/manual/PIP-MG%20(PF1.0)/PIP-MG%205KVA%20manual-20190717.pdf

Raj174

@kakarot
This inverter looks like it has only one charge controller. I agree with Photowhit and would recommend wiring 2 series strings of 4 panels in parallel. The strings can be paralleled at a combiner box using two 300volt 20amp fuses or breakers. If you are within about 10 degrees of the equator, then a virtual array of 4 series panels east and 4 series panels west should work well. I agree with Mike, a flat array will not be optimal. I would suggest about a 35 degree angle on the panels.

kakarot

Max PV input VOC  is 145V for the MS 5000w model.

Each panel is: Voc 59.01v

Raj174 said:

@kakarot
This inverter looks like it has only one charge controller. I agree with Photowhit and would recommend wiring 2 series strings of 4 panels in parallel. The strings can be paralleled at a combiner box using two 300volt 20amp fuses or breakers. If you are within about 10 degrees of the equator, then a virtual array of 4 series panels east and 4 series panels west should work well. I agree with Mike, a flat array will not be optimal. I would suggest about a 35 degree angle on the panels.

"2 series strings of 4 panels in parallel"

I've tried to make two groups of 4. then wire them in parallel with two solar extension cord to the inverter  ++, -- terminal but the voltage is too high,  stops working.

Now I have one group with 3 panels, and another group with 2 panels.  generating about 1.3kw

Newbie question, Do i need to change the connectors in order to wire ++ and --  to keep the voltage lower?

I'm doing this without a combiner box

ANYONE WITH A CLEAR DIAGRAM please.

Raj174

If that is the case, then 2 in series by 4 in parallel should work well. All wiring shown should be #10 AWG or larger. Panels are wired positive to negative. Here's a rough drawing. It may be hard to get, but a combiner box would make this much easier and safer.

burnin_daylight

Looks like it was assumed you had the “MG” model, but must in fact have the “MS” model. According to their datasheet, max PV input voltage is 115V, which is kind of an odd max. If the max input really is 115V, you can’t series at all. Your panel VOC is 59V, so 2X in series puts you at 118V. Take into account cold temp coefficient, and you could be quite higher. 

If the max PV input is actually 145V as you say, the diagram from @Raj174 will work perfectly. 

kakarot

Raj174 said:

If that is the case, then 2 in series by 4 in parallel should work well. All wiring shown should be #10 AWG or larger. Panels are wired positive to negative. Here's a rough drawing. It may be hard to get, but a combiner box would make this much easier and safer.

Thanks Raj174,

So basically I have a positive and a negative bus bar.  All positives on positive busbar, and negatives on negative. Then from there two wires to the inverter.

30 A breaker on each positive wire ( 4)

Raj174

You will have a negative PV bus bar, but all 4 positive lines should be connected each to a 30 amp DC breaker. Those breakers need to be combined to a single #4 AWG cable to a main PV Breaker, maybe 83 to 100 amp DC. Combiner boxes make this very easy.

Photowhit

kakarot said:

30 A breaker on each positive wire ( 4)

Unless the specs have changed again, the panels are mounted in series, you have posted the; "Maximum series fuse rating 20A". For each string (2 in series) should have a 20 amp fuse or breaker. 

Raj174

Photowhit said:

kakarot said:

30 A breaker on each positive wire ( 4)

Unless the specs have changed again, the panels are mounted in series, you have posted the; "Maximum series fuse rating 20A". For each string (2 in series) should have a 20 amp fuse or breaker. 

That are correct Sir, thanks for catching that Photowhit.

kakarot

https://www.amazon.com/dp/B072N7W575/ref=psdc_2236628011_t1_B07FH7JTTL

Would this work?

Raj174

No, it has 10 amp fuses and you need 20 amp and breakers are more useful.

I would recommend this one:

https://www.solar-electric.com/mnpv6.html

With four of these 20 amp DC breakers:

https://www.solar-electric.com/midnite-solar-mnepv-20-amps-circuit-breaker.html

All of these are sold on Amazon at a higher cost.

Not sure if your hybrid inverter has an PV input breaker, if not I'd recommend one.