230 Ft run from Panels to Off Grid Inverter trying to minimize voltage loss

[sabo]

I have 20 250 watt used panels from San Tan
I am considering the EG4 6.5 KW 48 Volt ( 1 to start another in 6 months )

EG4 6000XP Off-Grid Inverter | 8000W PV Input | 6000W Output | 480V VOC Input | 48V 120/240V Split Phase | All-In-One Solar Inverter

The EG4 6000XP is a cutting-edge 48V split-phase, off-grid inverter and charger, designed to revolutionize your energy needs. With an impressive 8kW of PV input capacity and an efficient 6kW continuous power output, it also serves as a battery 140A charger. What sets it apart is its scalability...

signaturesolar.com

I am concerned about the Voltage Loss. Im very new to solar. I have read some forum posts on a few forums. There was some debate between running Solar Cable and AWG. So far it sounds like it is best to use Solar Cable from the panels 230 ft to the inverter. Input requested on these statements. Also input on the number of panels to run in series is requested.

Are all Solar cables the same thickness or do I need to buy a specific size for this run?

Is the fan noise on the newer EG4 6.5 Kw inverters still excessive?

I have a solar combiner box. I can use this if needed.

 

[Rednecktek]

You're going to need the VoC numbers off the back of the panels to see how many you can get in series. You might be able to do 20s in one big array, then you can look up voltage drop calculators and start upping your wire size to get your voltage drop down.

You'll likely need to get some hefty direct bury and a junction block to get the PV wires connected to thick cable.

 

[DougfromdaUP]

230 feet isn’t that far.
The size of wire needed primarily depends on current. Your inverter will accept voltages up to 500.
You should be able to run 300 volt or so strings without exceeding the 500 volt open circuit limitation. 2500 watts at 300 volts is only 8.3 amps.
South wire has a great loss calculator where you can see what the voltage drop will be. For 8.3 amps at 230 feet #12 would only be a 2.18% drop. Not big wire at all

 

[DougfromdaUP]

As to which type of cable to run, how will it be installed?
In conduit use Thhn/thwn,not “solar” wire.

 

[sabo]

As to which type of cable to run, how will it be installed?
In conduit use Thhn/thwn,not “solar” wire.

I was going to go overhead in the air on my fence and then into the attic space which has paper insulation. I was wondering if I would need to put the solar wire in conduit since my insulation is paper. Im not sure if that is at risk of heating or sparking in odd circumstances.

 

[timselectric]

PV wires inside a building must be in metal conduit.

 

[sabo]

Looks like the flicker issue has been resolved.

RESOLVED: EG4 6500EX and 6000EX Lights Flickering FIRMWARE

We are releasing a firmware update on our website and here in this post that resolves the flickering light issue on the most recent batch of EG4 6000 and 6500 inverters. Who does this affect: people with EG4 6k and 6.5k units Shipped after November first who are experiencing lights flickering...

diysolarforum.com

 

[CoolWill]

You will need a disconnect where the conductors enter the building. And they will need to be in a metal conduit inside the building. The conduit will also need to be bonded.

 

[striider]

Would microinverters help since they convert to A/C at the panel? I can't really find anything that says you can run longer distances over smaller wire though, so maybe not. https://www.ecowatch.com/solar/microinverters-guide
Ah, nevermind, the dual conversion to AC then back to DC is inefficient. Carry on, nothing to see here!

 

[DougfromdaUP]

You will need a disconnect where the conductors enter the building. And they will need to be in a metal conduit inside the building. The conduit will also need to be bonded.

I’m don’t think the disconnect has to be at the point of entry. Mine isn’t, and was inspected and approved.

 

[Zwy]

I have 420 feet one way from array to house. Panels are 49.65VOC, I run 8 in series to one MPPT in the 6500EX with another 8S string to the other 6500EX.

The key is to keep VOC near the max VOC rating of the MPPT and amps down. I have 10AWG THWN inside buried conduit. I'm pulling max watts of 4Kw per MPPT in full sun.

For the combiner box, it isn't needed with a high VOC rated MPPT. You could still use the combiner for fusing strings, have a disconnect (breaker) and surge protection, just don't combine strings for higher amperage.

A 250W panel has a VOC of around 37V. 10 panels in series per string with one string per MPPT would work well. That would be 370VOC and low enough not to be concerned about cold weather.

If you are running wire overhead and exposed, you will need to run properly rated wire for sunlight resistance which does drive up the cost. Two concerns, one the high voltage is nothing to mess with on DC. Overhead wires always carry risk. Two, how are you planning on supporting the run of 200 feet?

 

[DougfromdaUP]

Would microinverters help since they convert to A/C at the panel? I can't really find anything that says you can run longer distances over smaller wire though, so maybe not. https://www.ecowatch.com/solar/microinverters-guide

Microinverters would hurt, as far as minimizing wire size is concerned. They would limit the voltage to 240.
AC, when measured rms, takes same amount of copper as dc.

 

[Zwy]

Would microinverters help since they convert to A/C at the panel? I can't really find anything that says you can run longer distances over smaller wire though, so maybe not. https://www.ecowatch.com/solar/microinverters-guide
Ah, nevermind, the dual conversion to AC then back to DC is inefficient. Carry on, nothing to see here!

Micros would be fine with some shading problems, the loss due to conversion might be easily made up.

Long distances can be run on small wire DC circuits by running higher voltages.

 

[sunshine_eggo]

https://eg4electronics.com/wp-content/uploads/2023/03/EG4_6.5_Manual_2.3.1.pdf

worst case 4000W array (max current, min voltage) per MPPT with a single pair of 10awg wires:

18A Imp
222Vmp

Not atypical for a 5S2P array of 24V panels around 325-350W.

3.73% voltage drop:

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

Arguably acceptable as that's only a 3.73% loss in power.

Single string of the same panels with 8 in series vs the 10 in 5S2P:

9A Imp
336Vmp

1.25% loss:

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

Point is this shit isn't rocket science. It can be calculated and there are many tools readily available to help the DIYer.

 

[dcg9381]

PV wires inside a building must be in metal conduit.

That's news to me. Not challenging it, but have a NEC citation? No PVC due to heat dissipation differences?

I am concerned about the Voltage Loss. Im very new to solar. I have read some forum posts on a few forums. There was some debate between running Solar Cable and AWG. So far it sounds like it is best to use Solar Cable from the panels 230 ft to the inverter. Input requested on these statements. Also input on the number of panels to run in series is requested.

Are all Solar cables the same thickness or do I need to buy a specific size for this run?

Is the fan noise on the newer EG4 6.5 Kw inverters still excessive?

Sabo,

The best way to do this is to push high voltage and less amperage. I didn't look up the specs on your panel, but you want high voltage (within the limits of the inverter). It's worth mentioning that high voltage DC is "more risky" to work with.

You need to run a "voltage drop calculator" once you know your string voltage / amperage. It'll help you select wire type. In general, you want to see less than 3% loss.

I have the EG-4 6500EX's. I do not find them excessive (but they are in my shop). They are louder than my Frontius inverter, but no where near as loud as a Dell Server, etc.

 

[Zwy]

That's news to me. Not challenging it, but have a NEC citation? No PVC due to heat dissipation differences?

690.31(D) Direct-Current Circuits on or in Buildings.

Where inside buildings, PV system dc circuits that exceed 30 volts or 8 amperes shall be contained in metal raceways, in Type MC metal-clad cable that complies with 250.118(10), or in metal enclosures.

www.electricallicenserenewal.com

 

[CoolWill]

I’m don’t think the disconnect has to be at the point of entry. Mine isn’t, and was inspected and approved.

It doesn't necessarily have to be outside, but it has to as close to the point of entry as possible. You shouldn't, for example, run it through your house for 50 feet. It should either be on the outside, or immediately inside. Also, passing an inspection doesn't mean the install is code-compliant.

 

[zanydroid]

That's news to me. Not challenging it, but have a NEC citation? No PVC due to heat dissipation differences?

It can be MC too (in the citation too, but the previous note called out conduit which is not the full picture).

 

[dcg9381]

690.31(D) Direct-Current Circuits on or in Buildings.

Where inside buildings, PV system dc circuits that exceed 30 volts or 8 amperes shall be contained in metal raceways, in Type MC metal-clad cable that complies with 250.118(10), or in metal enclosures.

www.electricallicenserenewal.com

Thank you. Appreciate the education. Learned something new today.

 

[timselectric]

That's news to me. Not challenging it, but have a NEC citation?

NEC 690.31 (d)

No PVC due to heat dissipation differences?

It's for physical protection from ungrounded circuit conductors.