Running wire from solar panels to equipment 100 feet away

iamrich

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Dec 17, 2020
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Elgin, Texas
You can always use a power distribution block so there isn't really a limit on gauge.
I was just pointing out the terminal pins on the controller will not accept bigger than 8awg. Of course if you bring all the lines right to the controller and then use a tiny length of 8awg you can push a lot more power through it.
 

sunshine

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Apr 24, 2020
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510
Hello

I'm dealing with similar issues on the off-grid system I'm installing.
The shortest distance from the clearing where I might be able to mount PV's to an enclosure (small barn) is 150'.
I'm not eager to have both my (8) SOK 206 amp batteries and my 48 volt 12k Sigeneer AIO inverter/charger outside just to gain proximity to the panels, the installation will be about 150 yards from my house, and there are a lot of trees obscuring visibility. The barn is still 100 yards or so from my house, but that will be an AC run.
I was originally going to run my batteries in 2S4P to obtain the 48v required, now I'm facing how to safely and economically run my DC wiring from PV's to AIO and batteries.
Now, I'm wondering what would be the optimal configuration for the DC wiring? I'm likely to add panels as I can obtain them.

Here's the Sigeneer specs

''3.4 PV Wiring CAUTION: Before connecting to PV modules, please install a separate DC circuit breaker between inverter and PV modules as per the solar charger rating. The PV terminal pins can accept cable size up to 8AWG, and the torque for the screws is 1.8Nm. Max. PV Array Open Circuit Voltage is 150V/250dc, please make sure Open Circuit Voltage (Voc) of PV modules does not exceed 150/250V and is higher than 34Vdc. The PV voltage must be higher than battery voltage to activate charging. There is no voltage boost in the MPPT module. PV Array MPPT Voltage Range: 60~145/245Vdc Minimal battery voltage for PV charge: 34Vdc"

Start with the wire gauge that will give you 34Vdc at the end!...must be for the 24v battery...x2 for 48v
Check your wallet to see how heavy the gauge you can go up to. 250vdc means it won't be too expensive!
 

Guido1

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Joined
May 16, 2021
Messages
16
@Guido1 You need to provide the max Voc that the inverter/charge controller you plan to use can take. Just in general, the higher the voltage the smaller the gauge of wire you can use. I have mine about 600ft away and am "only" using charge controller that can take up to 250V Voc. It somewhat depends on what your preferences and priorities are.
Hello, Iamrich

Just found this under "features", but it appears I was too slow.


FEATURES​

• 12000 watt low-frequency inverter 120/240Vac Split Phase output
• 60A*2 MPPT solar charger, Voc 250V
• BMS port
• 36000-watt surge for 5 seconds – 3x surge capability
• AC/Battery/PV Priority Selector
• Multi-Stage Smart charger 100 Amp
• 10msec typical transfer time
• optional 25W power save mode
 

Guido1

New Member
Joined
May 16, 2021
Messages
16
I
''3.4 PV Wiring CAUTION: Before connecting to PV modules, please install a separate DC circuit breaker between inverter and PV modules as per the solar charger rating. The PV terminal pins can accept cable size up to 8AWG, and the torque for the screws is 1.8Nm. Max. PV Array Open Circuit Voltage is 150V/250dc, please make sure Open Circuit Voltage (Voc) of PV modules does not exceed 150/250V and is higher than 34Vdc. The PV voltage must be higher than battery voltage to activate charging. There is no voltage boost in the MPPT module. PV Array MPPT Voltage Range: 60~145/245Vdc Minimal battery voltage for PV charge: 34Vdc"

Start with the wire gauge that will give you 34Vdc at the end!...must be for the 24v battery...x2 for 48v
Check your wallet to see how heavy the gauge you can go up to. 250vdc means it won't be too expensive!
was scoping out 2/0 welding cable, but I'm now wondering about the 34Vdc charging threshold. I hope that I can charge (4) groups of (2) batteries in serial config (2S4P?) and have the charger see the equivalent of a 48 Vdc load?
Jeez, I thought I only had one significant problem to contemplate....Any thoughts on the applicability of 2/0 cable for a 150' run? Or, should I attempt two or more sets of cable? I'd hate to have to run more than a single pair of that copper stuff, they're very proud of it.
 

Guido1

New Member
Joined
May 16, 2021
Messages
16
''3.4 PV Wiring CAUTION: Before connecting to PV modules, please install a separate DC circuit breaker between inverter and PV modules as per the solar charger rating. The PV terminal pins can accept cable size up to 8AWG, and the torque for the screws is 1.8Nm. Max. PV Array Open Circuit Voltage is 150V/250dc, please make sure Open Circuit Voltage (Voc) of PV modules does not exceed 150/250V and is higher than 34Vdc. The PV voltage must be higher than battery voltage to activate charging. There is no voltage boost in the MPPT module. PV Array MPPT Voltage Range: 60~145/245Vdc Minimal battery voltage for PV charge: 34Vdc"

Start with the wire gauge that will give you 34Vdc at the end!...must be for the 24v battery...x2 for 48v
Check your wallet to see how heavy the gauge you can go up to. 250vdc means it won't be too expensive!
So, I just need to check the voltage drop from 48V and ensure it doesn't fall below 34V after a 150' run of whatever gauge cable I end up with?

It appears, by using a voltage drop calculator, even 6 AWG wire only shows a 3.55 volt drop over 150' with 30 amps and 48 volts. Unless I'm missing something (entirely plausible) that looks like something I could certainly live with.
 
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sunshine

Solar Addict
Joined
Apr 24, 2020
Messages
510
.Any thoughts on the applicability of 2/0 cable for a 150' run?
Use this or there are others somewhere on this site:

Remember the charging amperage of the inverter is only 60 amps on the low voltage side not the input.. Use that in the calculator at the 250v string voltage. I'll do the calc later after work!!
 
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