Distance between Panels, Battery Bank, and Load Center - Problem?

[forbin]

There will be 16 panels on my roof. However, the only place where I have space for the rest of the components--48V batteries, all-in-ones, etc--is in a shed about 40 feet away. So the power will go 40' from the roof to the shed, then another 40' back from the shed to the house. Is that a problem for loss, cable size, etc?

 

[DThames]

What is the max PV input voltage of your AIO? The size of wire and the number of wire runs will be largely dependent on that voltage rating. If you can run 450v DC input (for example) you can have a rather normal size wire and be okay. If 150v max, you will need more wire but still okay if you size it right. That is for the PV to the AIO. From the AIO to the house, are you doing 240v or 120v? Either should be fine but again the right size wire for amps need to be determined. What is the output volts and amps of the AIO?

 

[MichaelK]

Here is a link to a voltage drop calculator that you can use to answer all your questions.

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

As an example, assuming you wanted to wire your 16 panels as two parallel strings of eight in series (that's 8S2P), here is the voltage drop you'd see with 10 gauge solar cable.

 

[timselectric]

As long as the batteries are close to the inverter.
Wire size increases on the others won't add much more cost.

 

[forbin]

What is the max PV input voltage of your AIO? The size of wire and the number of wire runs will be largely dependent on that voltage rating. If you can run 450v DC input (for example) you can have a rather normal size wire and be okay. If 150v max, you will need more wire but still okay if you size it right. That is for the PV to the AIO. From the AIO to the house, are you doing 240v or 120v? Either should be fine but again the right size wire for amps need to be determined. What is the output volts and amps of the AIO?

I'm currently focused on the EG4 6500EX-48, which has a max DC input of 500V and max continuous output of 6500W @ 120V, but I am considering 2 of them so I can run 240V for A/C.

 

[forbin]

Here is a link to a voltage drop calculator that you can use to answer all your questions.

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

As an example, assuming you wanted to wire your 16 panels as two parallel strings of eight in series (that's 8S2P), here is the voltage drop you'd see with 10 gauge solar cable.
View attachment 102407

That's an excellent resource, thanks!

 

[MichaelK]

I'm currently focused on the EG4 6500EX-48, which has a max DC input of 500V and max continuous output of 6500W @ 120V, but I am considering 2 of them so I can run 240V for A/C.

This superficially looks like one of the better-made AiO units. It has 5 seconds of surge to 150%, and it also has UL certification.

 

[DThames]

I'm currently focused on the EG4 6500EX-48, which has a max DC input of 500V and max continuous output of 6500W @ 120V, but I am considering 2 of them so I can run 240V for A/C.

Look at your panel's Voc and if they are 72 cell, it is likely you can get 8 in series (someone already mentioned this) and stay under your 500v max. So you could easily only have to deal with 10-12 amps per string of 8 panels. Have you picked a panel out yet?

 

[forbin]

Look at your panel's Voc and if they are 72 cell, it is likely you can get 8 in series (someone already mentioned this) and stay under your 500v max. So you could easily only have to deal with 10-12 amps per string of 8 panels. Have you picked a panel out yet?

Currently looking at the SolarEver 455's which have 49.35 Voc, which works out to 394.8V per string, so I think we look good from that perspective.

 

[DThames]

Note, I have some PV runs about 60 feet long, with about 15-20 amps on 10ga wire and they seem fine.

 

[rhino]

it also has UL certification

You need to be careful what that means. It is NOT UL listed.

 

[Hedges]

Long PV run of skinny wire is often fine. It will cause power loss, I^2R = W. It will reduce Vmp seen by controller. It has no effect on Voc.

I run 200' (each way) 12 awg for 7A 350 Vmp strings.
There is no set rule on percentage voltage drop for PV runs. If running 1000', you might accept 25% or 50% loss at peak current, because cheaper to add PV panels than to buy heavier copper wire.

 

[MichaelK]

You need to be careful what that means. It is NOT UL listed.

Excerpt from : https://www.polycase.com/techtalk/electronics-tips/ul-listed-vs-ul-certified.html

The term “UL Certified” has multiple meanings. First, the term is sometimes used as a general term in reference to any and all types of UL certifications, including UL Listed and UL Recognized Components. However, when you’re evaluating component compliance, it’s important to look at specific types of UL certifications.

The most correct and specific use of “UL Certified” refers to UL’s Enhanced Certification mark. If you see a badge on a component or device that says “UL Certified,” it’s part of the Enhanced Certification system. This system consolidates multiple types of safety and performance information into a single mark.

Among other changes, the UL Enhanced Certification badge contains information on the specific standards that a product has been tested for. The Enhanced Certification badges contain a descriptor of the standards originally part of the UL Classified badge, such as SAFETY, ENERGY, or MARINE. These descriptors refer to sets of testing standards designed to measure performance in specific contexts.

UL Enhanced Certification badges also contain the manufacturer’s UL file number and an opportunity to add a QR code for fast and easy traceability. Remember that although UL is eventually transitioning fully to the UL Certified badge, the organization has emphasized that the original marks remain valid and acceptable in their usual contexts.