Solar battery 75' from house

[kc130up]

Why not just get a regular 9000 btu unit for about $500, instead of $1600 for the eg4

A buddy got the EG4 last month with a few solar panels. The install was super easy with the self charged coolant, i just figured I'd get the same thing when the time comes.

I wont need the solar panels, so if I can get a regular mini split that installs just as easy for $500. That works for me.

 

[kc130up]

I did it with 0% experience, 3 years later and 2 expansions; 0 issues.


These voltages sound way to high for a happy MPPT. Did you do cold weather calculations on VOC?

I did. I will admit I didn't understand as much about solar panels when I originally did the calculations months ago, so I just did it again using the Midnight solar tool.

The coldest it gets here is -10. For the FB21, max MPPT voltage is 600v. At -15 degrees the VOC would be 596v.

If 26.64a is not pushing the limits of the FB21, I could do series parallel and only use 2 MPPT's.

Input values based on the panels spec sheet (SEG-415-BMD-HV) :

 

[1201]

I did. I will admit I didn't understand as much about solar panels when I originally did the calculations months ago, so I just did it again using the Midnight solar tool.

The coldest it gets here is -10. For the FB21, max MPPT voltage is 600v. At -15 degrees the VOC would be 596v.

If 26.64a is not pushing the limits of the FB21, I could do series parallel and only use 2 MPPT's.

Input values based on the panels spec sheet (SEG-415-BMD-HV) :

View attachment 284557

Use the midnight Barcelona calculator, not the classic calculator.

15 in series will be too much for -10

I have similar panels and I did 14 in series.

You might want to do fewer so you are not locked into a 600v inverter forever.

 

[42OhmsPA]

I did. I will admit I didn't understand as much about solar panels when I originally did the calculations months ago, so I just did it again using the Midnight solar tool.

The coldest it gets here is -10. For the FB21, max MPPT voltage is 600v. At -15 degrees the VOC would be 596v.

If 26.64a is not pushing the limits of the FB21, I could do series parallel and only use 2 MPPT's.

Input values based on the panels spec sheet (SEG-415-BMD-HV) :

View attachment 284557

Look at the working range for the MPPT not the specs....

 

[kc130up]

Look at the working range for the MPPT not the specs....

Understood. The working range is much lower, 440v. At that voltage, it's ~11 panels per series string.

If I series parallel array1: that's 22 panels, then do the same for array2, another 22 panels. that gets me to 44 without needing the third MPPT. If the inverter does end up in the shed, I can hook the 5 existing panels connected to the EG4-3K to the third MPPT. Not a lot, but another 2000Watts.

Now I just need to research the type/specs of MC4 inline fusing required for series parallel...

Thanks for the info gents!

 

[42OhmsPA]

Now I just need to research the type/specs of MC4 inline fusing required for series parallel...

None needed. More than 2 strings in parallel you need proper protection.
Personally I use disconnects on every string I run.
I wouldn't use anything inline. A combiner box is the route I would take.

 

[kc130up]

Excuse my ignorance, but I thought combiner boxes were used with Microinverters w/ AC?

 

[SparkyJJO]

There's also DC combiners. If you have more than one series string of panels into one MPPT you'll need something to combine things together.

 

[42OhmsPA]

Here's a photo I found of one I built years ago.

 

[kc130up]

So bring 4X series strings down the side of the house, into a combiner box to make 2X SP strings?

 

[42OhmsPA]

So bring 4X series strings down the side of the house, into a combiner box to make 2X SP strings?

If the MPPTs can handle the parallel current without excess clipping that will be fine.

 

[CaySol]

So bring 4X series strings down the side of the house, into a combiner box to make 2X SP strings?

The Flexboss mppt 1 and 2 can parallel the strings in the unit. No need for a combiner box.

It’s 3 MPPTs with 5 string inputs.

 

[kc130up]

The Flexboss mppt 1 and 2 can parallel the strings in the unit. No need for a combiner box.

It’s 3 MPPTs with 5 string inputs.

You just saved me some money (and time), thanks!

 

[TM48]

I did it with 0% experience, 3 years later and 2 expansions; 0 issues.

Alias poor 42 we knew him well........

 

[42OhmsPA]

Alias poor 42 we knew him well........

Brain dead from the work day, not getting it...

 

[ricardocello]

Brain dead from the work day, not getting it...

We don’t get too many paraphrased Shakespeare quotes on diysolarforum…