Great to know. I have been using street light cables that I scored from work around 4 1/2 years later and still going strong 💪 the array voltage is 100volt. Aloha from Australia ❤
10awg is oversized for what you’re running on it. Until you start to approach 30amps, you’re fine with 10awg. If you plan to exceed 100-150 feet I wouldn’t bother upsizing the wire.
Very interesting video and you turned me on to buying a cheap tablet so I can see all of my Victron or Blue Tooth controllers rather than using my phone. I made a couple of observations that I believe some new to solar folks may find useful. Since you are running panels in series, the voltage is higher and the amperage is lower. Amps or load is harder to push through small cabling. Its like a drinking straw when sucking up a milkshake....the colder the shake, the harder it is to get the ice cream. I too have experimented with various and frankly off the wall uses of wire. For runs at about 50 feet, believe it or not I am using 16 to 12/3 outdoor rated extension cords and I cut them in half and fuse the three connectors together forming a larger conductor. On sale, you can find these cords for $16-24 at walmart and I buy the bright green ones...my point is that if you price shop you'll find anything with RV or solar in the name means you'll pay more $$! A spot check of voltage at the panel and then on the other end (the fuse in won't show much of a delta) and that is due to voltage......but when a load is formed you will see the loss......I tried this by taking the 100ft cord and testing the panels to the controller, then when I cut the distance in half and fused the three connectors it was night and day......but to your points, you're spot on especially when using a higher PV voltage since the amps will be lower. This is why I have been setting up multiple arrays in various directions to minimize shading and series connecting panels......Pv cables are expensive per foot but I agree the jackets do work well in the sun. I have some that have been outside since 2015 and the red fades to a pinkish white. end of book, have a good week! Aloha from SE Michigan.
Great video. Seems 10 awg is the way to go. I just picked up a ferrule kit for next to nothing not long ago. I don't like open strands of wire and the ferrules keep it nice and neat. So cool to know that you get this great amount of power on these long runs. Thanks so much for taking the time to put this video together. Cheers !
Victron's official stance on ferrules is: Don't use them for the gate type cable clamps as they will reduce contact area with the wire and could result in a fire due to excessive heating.
I mostly use 10 gauge, but I think its a choice. Actual losses depend only on current, so maximizing the string voltage and minimizing the current results in far lower losses. You've already done that for the most part, your setup is fairly optimal I think. You could measure the actual losses. On a solid sun day where the voltage doesn't vary a whole lot, measure the voltage at the solar panels, and measure the voltage at the charge controller. While charging at full speed, of course. See what the voltage drop is between the two. Take several measurements just to be sure you aren't getting variations due to clouds, foliage, etc. P = I * V so the efficiency over the wiring will simply be Vcontroller / Vpanel. -Matt
Exactly. And if you have an extra wire you can run from the solar panel to near the charge controller, you can use it to measure 1/2 the voltage drop, which doubled gives you the entire drop. How? Two wires connected to solar negative and one of those connected to the charge controller, and the other not connected. One wire connected from solar positive to charge controller. Meter positive to charge controller positive. Meter negative to charge controller negative has the total loss. Meter negative to spare wire end has 1/2 the loss. Running one extra wire and being able to change where it connects on the panel end allows you to measure and compute losses for all the runs in the system.
I think the difference is in the total power across the while day. It looks like it is making about 20-30 Wh more with the 8 AWG wire. But it could also be newer panels? I think recording the totals for each day over a month might show you the difference. Just getting into the soalr world myself but my 2 cents as a newbie :)/ Always like your videos.
I take your two cents to heart. I have noticed going back in daily logs that the 8ga. string is usually 100-300wh more than the lower sting. I always assumed it was because the top string is in full sun earlier, and later in the day by several minutes each side, while the lower has a leaf or two worth of shadows. Hard to know for sure I guess. But pretty darn close under full sun on both. Aloha, and Mahalo for that! 🤙
I always oversize my wiring by one size…at least. It doesn’t hurt anything, you’re out a few more dollars, no extra labor and if you need it you’ve got it down the road. I can guarantee that you will always need more PV. I’m up to 50+kWpv and my sizing practices have came in handy more than once. If you punch in some numbers into your online wire sizing tool, you will see that it takes some big cables once you get out past 100 feet and above 10 A, which is standard current for 400+ panels. I want to be under 2% loss.
Mmmm; Around 9:40 in video the app shows, upper panel has 430wh vs 410wh for the lower panel. The app may be rounding up/down a few decimal points, but over time mili watts add up.
Yeah, I do get slight wh difference at end of day, but the top string gets in absolute full sun earlier, and a few minutes later throughout the day. Pretty close otherwise. Aloha! 🤙
The resistance per foot between 8 and 10 AWG is pretty close, so at 10A for 60 ft run you will see a voltage loss of about 0.6V in a 10 AWG wire and about 0.4V in an 8 AWG wire. Because the current is relatively low in the two types of wires and the runs are short, the I^2xR losses are really negligible.
The whole video is about how there is no difference between your 8 and 10AWG run numbers. But then you show the "8"AWG at 7:22 and it is a 6mm2 wire apparently per the label if I read that right. . That is between 10 and 9 AWG, not 8! So, that would explain the same numbers. Was that sold to you as 8AWG? IIRC you even stated that the wires look similar in size and they do in the vid. Well, IME I can definitely see a difference in size between 8 and 10 gauge wires with similar insulation. You may want to double check your 8ga wires...
I have 10 gage 600volt 30amp wire for my 2 50 foot run camper extension cable works good super video oh my wire has a 3rd wire for a ground one of my inverters require earth ground great video
i think it meant more in the old day when we were running pwm controllers and had to keep the system voltage low to match the battery voltage leading to higher current in the wires if one were to have a decent bit of power,,, i run 4 x 505w panels on a 30feet cable, system voltage is over 150v giving me about 50A in my 24v battery bank i have detected no heat ,and i am still running 4 old 100w 12v panels on double household wire 2in series 2 parellel on a old pwm controller
It's the amps that require thicker cables! You run rather low amps because you run high voltage. So what you see is the benefit of running higher voltage (panels in series) hence lower amps. If you were to put your 5 panels in parallel you would get 5 x the amps at 1/5 the voltage. And then you for sure would see quite a difference with the 8 AWG vs the 10 AWG cable!
Are the panels wired in series? As you increase the voltage by wiring the panels in series the amperage for the panels stays low. Less heat is produced and less waste. Panels connected using parallel Y-splitters will maintain the low 12v but increase the amps basically adding all the 4.5 amps together. This is where heat and wire cable size becomes more of a concern. Using mppt controllers allows higher voltage and less amps which keeps heat down. PWM controllers usually can’t handle panels in series if they go above 50v so you need to use combiner boxes or y-splitters and increase amps.
Yeah you wont see any difference unless you are pushing more amps. Once you start maxing out the amp rating thats when you will see a difference. The smaller wire would start to create heat that would be where the energy loss would show up... lo g as you are that far beneath the amp rating at that distance you wont see much difference. Great test tho.
What display do we see in this RU-vid say around 8:55 where you are showing each string compared to the next and all visible at the same time? Is that an easy thing to do? Is it hardwired or wireless? Thank you.
And as long as that equipment stays cool itll last a long time. When you push them hard and make alot of heat... look out..maybe a week maybe a month... eventually heat kills electronics
Could you answer a question? I have a 30A solar charge controller, with 2 separate inputs, for 2 150w panels, what AWG cable would be needed for this. Thank you.
Does cleaning debris off panels produce more power? Curious what voltage measures at the panels and at the disconnect. Very interesting. Thanks for sharing
Did you purchase a Ferrule Kit or a crimper and Ferrules separately? Can you recommend what you are using as it sure looks like it is working great? Thank you for having so many of the things you use listed with the links! I just did not see the Ferrules or crimpers for them.
Ok I got to ask. You say the controllers are networked. If they are charging the same battery they are splittng the load and you are not going to see much of a differance. How many battries are they hooked up to?
nice look at your systems. That why I like MPPT Victron controllers. look at solar panel voltage . and amps. then look at amps into battery nice step up. my solar run is long. 100 ft . in NM conduct 6 AWG THHN wire. all UL and system is inspected for request of my home oner insurance. being a electrician I have current code book. and the NEC 2020 has a whole section on alternative energy codes. just make shore the solar panel cable is rated for the higher voltage. this can shock you good. it is DC higher voltage. that is why I put tarp over panels . no sun-no power. any fuses or breakers have to be DC rated at higher voltage. now on 48V DC system this is higher and can shock you. wet hands is a no no. dry everything first . what we learn is anything over 50V is a shock hazard . large systems can be 600V DC .
loss is proportional to power through the cable so at 85 watts little loss but if battery is discharged and full sun on panel's so 500wats or so you will see a bigger difference of course it's dependent on how your strings are wired is voltage higher to get the watts or is there a higher peek current if all your 500w panels are in series just look on back of panel if peek current it 5 amps then that's all your cable will ever see the current don't add if panels are in series only parallel so 5amps say is good 100 feet on 10 gauge
I use the same cables!😊 and there 4into1 parallel splitters are nice too. 8awg is better cuz 10awg will get lil warm over 35a but you're strings are hooked in series parallel? So you won't experience that heat, at higher voltage🤔.. idk.
It would probably make more difference on a PWM charge controller. The MPPT can drop the current and raise the voltage to help overcome the resistance in the wire. Power loss is proportional to current squared so halve your current and you've quartered your losses. Also if the two charge controllers are linked then they may be limiting output to the best available from the narrower guage wire. If one controller is the master and one the slave then it would make sense to have the master on the narrower guage wire as then the slave can match it (being higher spec) whereas vice versa if the narrower guage is the slave it won't be able to match the performance of the heavier guage system. Not sure if victron uses a master/slave config or if it is smarter than that!
I have 30 full size panels out in the field and 1,000 ft of wire The calculation shows about 1% loss, I could have done it with 14awg with similar loss
