Finally ready for Panels LV 6548

[TheCoachStone]

Ok, I finally have my LV6048 and batteries installed. I have been looking for panels to pair with my system, and I think I have found them.


LV 6548
Solar Charger Mode
Max PV Input Voltage (Voc) 250VDC
MPPT Voltage Range 90 - 230VDC
Number of Input Strings 2
Max PV Input Current 18A per input (2 x 10A strings OK)
Max Charge Current to Battery 60A + 60A
Max PV Input Power to Battery 3500W + 3500W
Recommended Cable Size for PV Connection 10-12 AWG

Panels
CANADIAN SOLAR 400W BIFACIAL
Nominal Maximum Power (Pmax): 400 Watts
Optimum Operating Voltage (Vmp): 38.7 Volts
Optimum Operating Current (Imp): 10.34 Amps
Open Circuit Voltage (Voc): 47.2 Volts
Short Circuit Current (Isc): 10.9 Amps

Can I run 2 strings of 6 in series for (each)

232.2v
10.3a
2400w

 

[sunshine_eggo]

Ok, I finally have my LV6048 and batteries installed. I have been looking for panels to pair with my system, and I think I have found them.


LV 6548
Solar Charger Mode
Max PV Input Voltage (Voc) 250VDC
MPPT Voltage Range 90 - 230VDC
Number of Input Strings 2
Max PV Input Current 18A per input (2 x 10A strings OK)
Max Charge Current to Battery 60A + 60A
Max PV Input Power to Battery 3500W + 3500W
Recommended Cable Size for PV Connection 10-12 AWG

Panels
CANADIAN SOLAR 400W BIFACIAL
Nominal Maximum Power (Pmax): 400 Watts
Optimum Operating Voltage (Vmp): 38.7 Volts
Optimum Operating Current (Imp): 10.34 Amps
Open Circuit Voltage (Voc): 47.2 Volts
Short Circuit Current (Isc): 10.9 Amps

Can I run 2 strings of 6 in series for (each)

232.2v
10.3a
2400w

You use Voc to see if you blow MPPT limits:

6 * 47.2V = 283.2V = blown up MPPT. 250V limit.

4S is the practical limit for those panels unless you never see less than 50°F.

 

[TheCoachStone]

You use Voc to see if you blow MPPT limits:

6 * 47.2V = 283.2V = blown up MPPT. 250V limit.

4S is the practical limit for those panels unless you never see less than 50°F.

And a combiner box would not help because it would double the amps, right?

 

[sunshine_eggo]

And a combiner box would not help because it would double the amps, right?

Combiner boxes are just ways of connecting strings in parallel while incorporating fuses or breakers.

IMHO, you could safely 2P those panels since they're just a little over the 18A limit and will rarely output 18A or more.

4S2P would be 3200W rated with 18A * 154.8Vmp = 2786.4 actual.

These 18A limited 250V MPPT are almost impossible to get peak power.

3500/18A = 194Vmp - almost impossible to hit this without blowing 250Voc.

 

[TheCoachStone]

Combiner boxes are just ways of connecting strings in parallel while incorporating fuses or breakers.

IMHO, you could safely 2P those panels since they're just a little over the 18A limit and will rarely output 18A or more.

4S2P would be 3200W rated with 18A * 154.8Vmp = 2786.4 actual.

These 18A limited 250V MPPT are almost impossible to get peak power.

3500/18A = 194Vmp - almost impossible to hit this without blowing 250Voc.

I do not mind coming in under 3,500w per string. My main concern is charging my 380ah of batteries every day, so it can handle most of the charging of my EV. Even if it doesn't the LV has a connection to the grid for backup.

So, 4S2P would look like this?

 

[sunshine_eggo]

I do not mind coming in under 3,500w per string. My main concern is charging my 380ah of batteries every day, so it can handle most of the charging of my EV. Even if it doesn't the LV has a connection to the grid for backup.

So, 4S2P would look like this?

Yep

 

[TheCoachStone]

Yep

Now, can I afford 16 of them?

Do I need to add anything special since I will be just over 20v per string?

 

[sunshine_eggo]

Now, can I afford 16 of them?

Do I need to add anything special since I will be just over 20v per string?

?

 

[TheCoachStone]

?

Oh, were you saying 4S per input?

 

[sunshine_eggo]

Oh, were you saying 4S per input?

No. I just don't know where the 20V came from.

4S2P on each MPPT is fine.

(16 total panels)

 

[TheCoachStone]

I thought because the panels are (Imp): 10.34 Amps that 4S2P would give the strand 20.64a total.

EDIT: (before I posted) I meant 20a! Sorry!

 

[jasonhc73]

I thought because the panels are (Imp): 10.34 Amps that 4S2P would give the strand 20.64a total.

EDIT: (before I posted) I meant 20a! Sorry!

You will not harm any MPPT by over-amping it. That is what an MPPT does, the MPPT puts the load on the panel, and this creates the amps. The MPPT will pull as many amps as it is built to pull.


The LV-6548 VOC limit will not "fry" if you exceed the VOC, it will just go into safe mode. Yes, if you make a string of 6*47.2=283.2 the inverter will just turn itself off. It is not a matter of if, it is a matter of everyday operation. An MPPT with no load, like in the early morning will be at the VOC, every day, and on cooler/cold days probably higher.