Hello, I've been tasked with running a very long wire from my solar panels to my camper and I'm just trying to figure out if it's possible within some sort of reasonable price. I am going to order 9, 250-watt panels and do them in 3s3p and I've essentially been tasked to run a wire to the 300 feet back into the woods where my dad wants to put our camper. These are the panels we'll be getting: https://store.santansolar.com/product/santan-solar-t-series-250w-snail-trails/ I'm sure the specifications will be important. I used a solar wire calculator from Renogy and it recommended 4 gauge wire but I have no idea where I would even find 300 feet of 4 gauge wire and please correct me if I'm wrong but, doesn't the wire need to be rated for PV? I tried looking and couldn't find anything that long over 8 gauge. I mean is there another way I can wire these panels to use a less expensive gauge or am I completely misunderstanding something because it looks pretty hopeless. My dad is extremely, well, persistent, and he wants to move the camper from 50~ feet from the panels to all the way in the back of our property for more privacy and I don't know if I'll be able to change his mind on it. Can you guys help me out?
Running a long wire
- Thread starter Scixxor
- Start date
If the wire run is to be permanent then you can run non-PV wire inside a buried conduit. Only use a length of PV wire from the panels to the conduit and maybe from the conduit to the camper. Basically, anywhere the wire is exposed to the elements.
You are looking at 600' roundtrip for the wire. Your panels in 3S3P will be roughly 112V at 27A. 4AWG seems about right for that.
You are looking at 600' roundtrip for the wire. Your panels in 3S3P will be roughly 112V at 27A. 4AWG seems about right for that.
Are you running this wire exposed on the surface? If so that's your biggest issue. If your running it in conduit you can use appropriately sized thhn/thwn type wire. Pv wire is rated for exposure. If you are just laying it on the ground you will need wire that is rated for exposure. You can make weatherproof splices in the wire to add lengths together.
Yeah your right burying the wire and using non PV wire would likely be my only option the problem is it would be going through thick woods and I have a lot of experience digging as I do landscaping work and digging through those roots would be practically impossible, I suppose I could just lay it out on the ground and cover it with dirt but getting that dirt would also be very difficult and expensive. Plus burying 300+ feet of cable would take an extremely long time.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 18,556
UF is UV resistant.
Just hang it from the trees.
If your SCC could handle a higher voltage, smaller wire would be the better option.
Just hang it from the trees.
If your SCC could handle a higher voltage, smaller wire would be the better option.
With that run length - it might be cheaper to look at a 250v mppt and go with a 5s2p (you would need one more panel). If your low temps aren’t very low (check the math carefully here!) maybe even a 6s2p - but that’s probably over the voltage line.
Going with high voltage and lower amps for long runs is usually better.
Going with high voltage and lower amps for long runs is usually better.
I'm afraid I'm not entirely familiar with the terms, what's UF? And are you saying just to hand 8 gauge wire from the trees and accept the loss because that's seeming like a pretty solid option. My all-in-one has a max VOC of 145 volts hence the sets of 3.
Yeah, I think that's a good option but with 8 gauge wire instead for less loss. With that being said how would I go about adding more solar panels? Would I just keep adding sets of 3 or what? My current plan was to not use a combiner box since it's only 3 in parallel and it would add an extra $300 which right now I can't afford or would it be possible to do something like 4s3p because of the drop in power over the long distance. With all this being said this is all months in the future but I want to learn everything about it now so I can prepare and know how much money I will need to save up.
Oh and thank you both so much for your replies I really appreciate your help!
Yeah the other option I was considering was going with a box that could accept something like 500 volts but I can't find anything near that high that accepts 24volts of batteries. My plan was to by this winter have 6 12 volt batteries and that seems like a hard goal seeing as I only have 2 right now. 8 just might not be possible but we'll see. Do you know of any all-in-ones that accept 24volts of battery and have something close to 250 volts of solar input? Oh and I live decently far north in west Virginia so are lowes can occasionally see in the negatives but only got in the single digits this year.
schmism
Solar Addict
The technical name for direct bury grey wire at the big box store.
Id also look for high voltage MPPT.
Cows like chewing on insulated cable. Any deer in the woods?
The link below may give you an idea for a cheap source of 30amp DC cable that comes with a joiner every 25m - you will need 8 and here it is rated for 240v.
Click 25m 10A Heavy Duty Extension Lead
Find Click 25m 10A Heavy Duty Extension Lead at Bunnings. Visit your local store for the widest range of products.
www.bunnings.com.au
Ah, thank you! Do you have any recommendations for something with a higher voltage? I looked and couldn't find anything high enough that would accept 24volts of batteries.
Go bigger then you need or run multiple at once. You tend to add panels over time and having the wire in place for that is a real benefit.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 18,556
They exist, but are very expensive in my opinion.
Don't connect solid wire to the charge controller.
You can change it over to stranded wire, before connecting.
If you haven't purchased anything, you might consider going with a 48v battery system. The AIO's generally are setup for a higher solar voltage.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 18,556
Also
VOC is a hard number. Don't go over it without expecting damage.
Voltage drop (due to long runs) doesn't affect VOC.
Voltage drop happens, when the load is applied.
VOC is a hard number. Don't go over it without expecting damage.
Voltage drop (due to long runs) doesn't affect VOC.
Voltage drop happens, when the load is applied.
rin67630
Solar Enthusiast
rin67630
Solar Enthusiast
3S/3P gives ~110V DC.
That is a killer voltage that can draw very long sparks. You will have to very carefully chose your breakers !
Or be very cautious to cover your panels before unplugging.
That is a killer voltage that can draw very long sparks. You will have to very carefully chose your breakers !
Or be very cautious to cover your panels before unplugging.
