PV wire question

[cedgo]

Hello all,
Trying to wrap my pea brain around this solar thing.

Have four Qcell 480 watt panels.

Controller is 50' from panels.

What gauge cable am I looking at?

AND, would it be better to run two smaller gauge cables as opposed to one cable?

Rhanks so much,
cedgo

 

[Sanwizard]

Hello all,
Trying to wrap my pea brain around this solar thing.

Have four Qcell 480 watt panels.

Controller is 50' from panels.

What gauge cable am I looking at?

AND, would it be better to run two smaller gauge cables as opposed to one cable?

Rhanks so much,
cedgo

I would use two 10 gauge THHN wires, one red and one black. Then no worries when expanding.

 

[seneysolar]

Using PV wire has its advantages. Most quality pv wire can be direct bury and is sunlight resistant. THHN is neither.

10ga is kinda standard. But will vary depending on if panels are series or parallel configuration. With only 4 panels you can do either with 10ga. Just keep this in mind for future expansion.

 

[Sanwizard]

Using PV wire has its advantages. Most quality pv wire can be direct bury and is sunlight resistant. THHN is neither.

10ga is kinda standard. But will vary depending on if panels are series or parallel configuration. With only 4 panels you can do either with 10ga. Just keep this in mind for future expansion.

Code in my area called for conduit both inside and out.

 

[Mattb4]

When sizing wire the aspects you deal with is ampacity, voltage drop over distance and type of wire. So to answer your question Start with amperage it needs to carry now and if any future expansion might happen. With only 50ft of run you can fairly well ignore voltage drop. Type of wire comes into play only if it is not standard PV rated wire, either open air or direct burial installation.

 

[cedgo]

Replies appreciated!

Confused.

Question.

Won't the amperage exceed the capacity of #10 wire?

 

[Tulex]

Using PV wire has its advantages. Most quality pv wire can be direct bury and is sunlight resistant. THHN is neither.

10ga is kinda standard. But will vary depending on if panels are series or parallel configuration. With only 4 panels you can do either with 10ga. Just keep this in mind for future expansion.

All the Qcell 480s I looked up have 10 or more amps. That puts him at over 40 amps in parallel, so 10ga isn't going to work in parallel.

 

[Tulex]

Replies appreciated!

Confused.

Question.

Won't the amperage exceed the capacity of #10 wire?

If you aren't familiar with series vs parallel, This is a quick explanation.
Regardless of which option you choose, the wire simply has to be able to handle the total amps.
If you post panel details and ask specific questions, there are many on here that can help out.

 

[seneysolar]

All the Qcell 480s I looked up have 10 or more amps. That puts him at over 40 amps in parallel, so 10ga isn't going to work in parallel.

True. I guess I didn't assume all 4 would be paralleled. I was thinking 2s2p just to keep under whatever voc limits he might have on his controller and still keep voltage high enough for the 50ft run. Personally, i try to keep pv runs as high of voltage as i can.

 

[cedgo]

OK

The help is great!

The four, 480 watt panels are in series (48 volts).

50' between panels and controller.

Guage = ?

 

[seneysolar]

OK

The help is great!

The four, 480 watt panels are in series (48 volts).

50' between panels and controller.

Guage = ?

With all 4 in series, the Voc adds up but amps do not.

Series = 10ga is more than enough.

 

[Zwy]

OK

The help is great!

The four, 480 watt panels are in series (48 volts).

50' between panels and controller.

Guage = ?

10AWG even 12AWG would work.

I run 10AWG 420 feet with 13A at 360 to 380V. String voltage up to VOC limit (be sure to calculate temp coefficient) and amps as low as possible if shading will not be a problem.

 

[Mattb4]

OK

The help is great!

The four, 480 watt panels are in series (48 volts).

50' between panels and controller.

Guage = ?

Understanding specifications for your components is essential. Your panels should have a label for them. Your SCC (solar charge controller) should list them in its manual. Asking people how you should select wire gauge without providing real numbers to work with (other than the 50ft run distance) is going to mean that people have to make guesses. Some folks will know off hand your panels specifications because they have encountered or own them. Others like myself would have to be told or independently look them up. Instead you should provide them as part of your question. Saves effort and time.

You say you are going to series the panels. This means that the panels Voc will add up while the panels Imp will be the same as 1 panel. So what is your panels ratings? Now what is your SCC ratings for max PV Voc? If placing 4 of your panels in series places you at or above the SCC rating you can damage or destroy it.

Voltage that you run through the wires and current determine voltage loss over distance. The higher the voltage the less voltage drop for a given wire gauge. There are many voltage drop calculators for wire and distance on the 'Net so you need not do the hard math.