Solar panels to controller cable size (1 Viewer)

[Harsh]

Hello,

I think I am posting in the wrong group but would appreciate if anyone can share their knowledge regarding solar panels and cabling.
I am looking to install 6 solar panels connected in parallel ideally on my outhouse flat roof with the below spec and the distance Between the panels and the controller would be approx 10meters.

1. Maximum power ( P max) = 300Wp
2. Open circuit voltage (Voc) = 40.11V
3. Short circuit current ( Isc) = 9.61A
4. Max power Voltage ( Vmp) = 32.54V
5. Max system Voltage ( Imp) = 9.22A

Online calculators suggest 35mm cable, is this correct or would a 6mm cable would be enough ?

Please suggest if connecting 3 panels in series and 3 in parallel would be a good idea to reduce cable sizing

Thanks in advance

Regards
Harsh

 

[Revolvor]

What is the maximum input voltage and make/model of the solar controller that you plan to use?

Are you planning to charge 12v or 48v batteries?

 

[dunnah01]

If you're looking at a 240v domestic system then the voltage/wattage capacity of the inverter will limit the total volts of the panels in series. If you need to put them in parallel in a 12v setup then there will be a limited number of controllers that can deal with the amps

 

[MisterB]

If it's a domestic install, most solar panel installations use 6mm (or 4mm) cables between the panels up to the inverter in my understanding.

 

[oldiesontour]

Not the norm to parallel all panels for six panels .Panels are wired in usually series strings then strings are paralleld, if controller only has one input..,number of panels in a string and number of strings governed by controller input capacity

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[IRHP]

You definitely won't need 35mm. That could carry 200 amps

 

[RogerIvy]

Why all in parallel?
I’d suggest series, or at least one or two in parallel and then place those is series.

You might get away with 10mm2 cables if you want to stick to parallel. It would mean accepting a 10% loss and cables heating up to 70degC. I’d not install that personally, I’d place them in series.

 

[Revolvor]

See my post #2 - The OP still hasn't said what solar controller he plans to use. I want to wire domestic solar panels to a Sunsynk Charger/Inverter and the input voltage is 120v MINIMUM.

 

[autorouter]

You have the description of the panel spec wrong. '5' should be 'Max power amps 9.22A'. You can check this because max power volts x max power amps = max power: 32.54Vx 9.22A = 300W. In parallel the total amps would be 55A, and for a 10m there and back run would give a voltage drop of about 1% for 35mm² or 2% for 25mm². So 25mm² would be OK, less than the usual 3% guideline.

However the usual method with domestic arrays is to wire in series, to give a total voltage of over 100V, or often over 200V. You have to look at the input voltage of the solar controller, or more likely the hybrid inverter. I'm sure that two series strings of three panels, connected in parallel, or even a single series string of six panels, would be a better option.

Just be aware that 40V from one panel won't give you a shock, but 80V from two panels in series, or anything higher, is potentially lethal, especially if you are working on a roof at height.

 

[MisterB]

Hello,

I think I am posting in the wrong group but would appreciate if anyone can share their knowledge regarding solar panels and cabling.
I am looking to install 6 solar panels connected in parallel ideally on my outhouse flat roof with the below spec and the distance Between the panels and the controller would be approx 10meters.

1. Maximum power ( P max) = 300Wp
2. Open circuit voltage (Voc) = 40.11V
3. Short circuit current ( Isc) = 9.61A
4. Max power Voltage ( Vmp) = 32.54V
5. Max system Voltage ( Imp) = 9.22A

Online calculators suggest 35mm cable, is this correct or would a 6mm cable would be enough ?

Please suggest if connecting 3 panels in series and 3 in parallel would be a good idea to reduce cable sizing

Thanks in advance

Regards
Harsh

Raul will hopefully advise ....

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[Raul]

Sorry I can't help. There is lack of info. The configuration of the panels is dictated by the parameters of the gozmo you hook them to: IE inverter or a controller. Without that data, there is no point of suggesting anything.
Harsh can you expand?
What controller/ inverter you Using and their data, whats this for? Or what kind of system; battery or not. 6x300w its quite a bit of solar for a 12v system.

 

[Carpmart]

Why all in parallel?
I’d suggest series, or at least one or two in parallel and then place those is series.

You might get away with 10mm2 cables if you want to stick to parallel. It would mean accepting a 10% loss and cables heating up to 70degC. I’d not install that personally, I’d place them in series.

I watched you recent video WRT series vs parallel… I noted the partial shading experiment with the Victron panels. Are Victron panels unique in the partial shade performance or will I experience similar with my Craig Solar panels?

 

[Raul]

I watched you recent video WRT series vs parallel… I noted the partial shading experiment with the Victron panels. Are Victron panels unique in the partial shade performance or will I experience similar with my Craig Solar panels?

Victron panels are OK ish, for the partial or transient shade are better panels out there, much better. You will be equally ok with Craig's vs victron.