Solar Equipment location and inverter wire length

solarhungry · July 2017

I've been going back and forth with this. I have my equipment on the outside wall on my back porch on plywood. (The battery bank,inverter,controller,ect.)
I was really wanting to put the equipment inside the house directly behind that wall. But with the strong electrical smell and large battery bank I am not going to. Where the equipment is now bothers me some because it can be seen through my locked gate,video cameras,maybe some nukes but that's really not going to stop a thief if they really want it. But in the safe city I live in, the only person that may see it is the electric meter reader. I am building this to code as much as I have researched but just don't know about the electric company. It's off grid and they don't require permits for solar at this time in this city.
The battery bank has to stay where it is. Another option is.... I can put the equipment on the opposite wall across from it's location out of view but it would make my equipment to the battery about 11-12 feet. I am running 2/0 but the Midnite only takes up to 4 gauge. But I lugged back into a terminal post back into 2/0.
I know that controller wire to the battery can be the smaller wire or same size as controller. And the batteries and inverter cables have to be the largest gauge which I am using 2/0. I can move my midnite to the opposite wall and leave my inverters in it's old place , but guess it really doesn't solve out of sight out of mind or possible being hassled.
Guess my question is .....from the inverter to the 2/0 battery wire going to be a bad idea or major power loss of 12 feet? I really like the equipment out of view. Battery bank is about 2300 ah and plan on doing series of 48v near maxing out my midnite classic 150 around 90 amps. I have 6K of panels but have to do the math again but thought I will only be able to do around 5K ish. 48v @ 9 amp panels. Thanks,always great help here!

Raj174 · July 2017

Hi solarhungry,
I had similar concerns with my installation concerning security/noise. My solution was to enclose the porch to make an air conditioned, insulated room to house batteries and equipment. Wood siding, 2 by 4's, sheetrock, insulation, one door and one window. Cost about 1200 dollars in material and did the work myself over a few months.
If this is not an option for you then, In my opinion, I think the proposed 10 to 12 feet of cabling is acceptable, just not preferred. Looks to be about a 2% power lose to cabling not including PV in. Is it possible to use 4/0 AWG for the inverter cable? 4/0 would help with voltage drop on a long cable due to load surges.

Rick

mcgivor · July 2017

@solarhungry out of curiosity what inverter are you using? Going 48V is the best way to reduce DC current but the wattage of the inverter is key in determining conductor size, bringing the Midnite Classic indoors is also bringing the noise of the fans indoors, if that is a concern.

solarhungry · July 2017

Thanks guys! My system isn't complete but I did give it a test run with one battery. Your solar going to love that A/C room. I like that...I would like to do the same as well as budget comes along. Yesterday was 104 degrees here. I plan on putting together my battery bank this weekend. The 20 batteries that are unhooked are stored in the house right now out of the weather. I think it's going to be a failed attempt but I plan on putting a small fridge to my boxed bank and try to cool them down. On youtube a guy did it and had some ok results. But he did not vent his box. I have AGM batteries and the manufactor says to vent them. I plan on venting them and that's where I think the fridge cooling system is going to fail and not be able to keep up. I already have the fridge. If it fails the only loss will be the 2 sheets of insulation and time. But for me it's worth a try. Putting the system on the opposite wall is what I'll do then. I will do the suggestion of the thicker 4/0 wire for the inverter. I might have to make some calls around though. I recall only seeing up to 3/0 where I bought the 2/0.
As far as the inverter it's a 12V 5000 watt Jupiter. Not what I want but to get me by as I got it new and half the price. I would consider the 48v inverter but had my mind set on 24v charger inverter. I know the 48v is more efficient so it is still open for that when I finally have the money saved up for a good expensive inverter.

Estragon · July 2017

I would do the same as @Raj174 not only to avoid tempting thieves, but also to keep critters and curious humans away. I'd divide the enclosure so venting for batteries and for other gear are kept separate. Lining it with type x drywall on z strips would give a decent fire separation if that's a concern. Outside could be sided to blend in with existing porch. Depending on climate, I'd use some mineral wool insulation on the outside walls.

Vic · July 2017

solarhungry said, ... "I was really wanting to put the equipment inside the house directly behind that wall. But with the strong electrical smell" ...

Am curious about the origin of that "strong electrical smell"

None of the systems that I've ever dealt with had any electrical smell/aroma at all, whatsoever... what does it smell like? From piece/es of equipment does it originate?

Vic

Raj174 · July 2017

So you're starting out with 1200 to 1500 watts of solar panels and then later adding the rest when you go to a 48 volt inverter?

Rick

Solray · July 2017

Electrical smell is most likely caused by the ionizing of the air around the circuits or the smell of the flux and coatings used in the production of the equipment. All equipment has an odor, not everyone notices it. Smokers almost never notice it.

solarhungry · July 2017

Vic, I have an older 1500 watt HFT inverter about 5-6 years old. The electrical smell it puts out gives me a headache...so not sure how safe it is, it could just be like perfume and more of an annoying smell that causes the headache. It could be because it's an older inverter? Looking forward to see if the new one has a smell. It's not a burning electrical smell but like a strong smell like when I charge my batteries for my lipos,weed wacker and blowers that the chargers put out. That Jupiter 5000/10,000 surge is coming... likely be here Monday. Reason I went that route was the great deal and it should handle the 2 window units . As far as the older HFT 1500 inverter it'll run the smaller stuff. I just don't have all the funds for the 24v or 48v inverter yet. I didn't have the midnite on long enough for the fans to stay on constant. So not sure if it does.

solarhungry · July 2017

Rick, yes watts around there. I also have 16, 300 watt 24V panels I have to put up. But before I get another inverter. My big battery bank is going to need those extra panels for the load I plan for it. ( Total of 8 160 watt 12v panels and the 16 ,300 watt 24V panels. To clear, I want to run the panels in 48V series. Using less amps at higher voltage with many watts. Trying to get as high but not maxing out the classic 150. Hope that's not a bad idea. I am seeing in a number of videos where they have 2 or 3 classics but doesn't seem like there's that many panels unless it's a 12V system. I can't recall. Like they are using maybe half of the rated amps for the classic so it is more efficient? From my array to the controller is about 85' including going up the wall. I went ahead and just went with it and used 2/0 for that . Heavy copper and hard to work with. Took me hours to get those 2 wires in that conduit by myself with those 90 bends. For the ground I just put it in it's own 1/2 conduit.....wasn't even going to try and shove it in with the 2/0.

littleharbor2 · July 2017

solarhungry said:. That Jupiter 5000/10,000 surge is coming... likely be here Monday. Reason I went that route was the great deal and it should handle the 2 window units .

I don't know how they can legally sell an inverter in this configuration. Guaranteed it wont have a UL listing. If you were to hit that 10,000 watt surge limit you would be pulling over 800 amps (10,000/ 12 volts = 833 amps) That's going to take one helluva battery bank and cabling. Be careful with "great deals" when it comes to cheap inverters. Many of these don't last very long but the potential for catastrophic failure and possible destruction of your home make that great deal look not so great.

mcgivor · July 2017

Agreed you need to seriously reconsider using an inverter with such, how do you put it. ....outrageous, ridiculous, exaggerated specifications, the modified sine wave, probably square wave, won't agree with motors or switching transformers, be careful things are not always what they appear. Please understand we have your safety in mind, and not just being critical.

Raj174 · July 2017

@solarhungry
Large 12 volt battery systems have some inherent restrictions that you should be aware of. The classic CC will only be able to process about 1300 watts max at 12 volts. That is basically all of the 160 watt panels configured 4 strings of 2 in series, 2 strings of 4 in series, 4 300 watt panels in parallel or 2 strings of 2 300 watt panels in series. Another is that the 4/0 AWG cable will need a 250 amp breaker or fuss since the max amperage is 260 amps for type THHN. This will limit the 5000 watt inverter to 3000 watts. Also, due to the high amperage on the inverter cable, losses can be as much as 2% for this one connection depending on loads. It will probably be half that under normal operation. Voltage sag may be evident with surge on large loads. Double check connections because loose connections at high amperage can produce spectacular results, and not the good kind.

If you decide to go with a 48 volt inverter, the 300 watt solar panels could also be an issue for a 48 volt FLA (Flooded Lead Acid) battery bank. Two panels in series will deliver about 73 volts VMP. This is not high enough for the classic MPPT CC to consistently get the 64ish volts,or higher depending on temperature, needed to do an EQ charge on the batteries. Three panels in series may be an option, however it could push the classic into hyperVOC on cool/cold days, at which point it will not function until the VOC drops below 150 volts. Use Midnite's string calculator to get exact data for your location. If the battery bank is AGM then multiple strings of 2 panels in series should work fine.

Rick

mike95490 · July 2017

Solray said:

Electrical smell is most likely caused by the ionizing of the air around the circuits or the smell of the flux and coatings used in the production of the equipment. All equipment has an odor, not everyone notices it. Smokers almost never notice it.

Maybe some "new car smell" for a couple days. But most modern consumer gear has gone through a PCB wash process to remove flux residue, and not even the 600V controllers are able to ionize air. Once you get ionized air, it becomes a conductive plasma and that's never fun. So I suspect the smell is something burning in the HorribleFright inverter,

littleharbor2 · July 2017

Sounds like the smell of burnt wire insulation.

Vic · July 2017

solarhungry said:

Vic, I have an older 1500 watt HFT inverter about 5-6 years old. The electrical smell it puts out gives me a headache...so not sure how safe it is, it could just be like perfume and more of an annoying smell that causes the headache. It could be because it's an older inverter? Looking forward to see if the new one has a smell. It's not a burning electrical smell but like a strong smell like when I charge my batteries for my lipos,weed wacker and blowers that the chargers put out. That Jupiter 5000/10,000 surge is coming... likely be here Monday. Reason I went that route was the great deal and it should handle the 2 window units . As far as the older HFT 1500 inverter it'll run the smaller stuff. I just don't have all the funds for the 24v or 48v inverter yet. I didn't have the midnite on long enough for the fans to stay on constant. So not sure if it does.

Thanks solarhungry for the added info.

After a few days/weeks, much of the aromas created by new electronics usually diminish to the point that they are not noticeable.

Some products that used Phenolic circuit boards can continue to emit odors. Also sometimes transformers that run HOT can emit odors.

Do hope that it is not the odor of insulation burning.

And seems certainly unlikely to arise from ionization, unless something is horribly wrong.

Seems like generally good advice that you are getting here. Good Luck, Vic

solarhungry · July 2017

Good advice indeed. I read the comments a few times and appreciate the input. I am going to have to take a look into these comments and get back to this as I can use some advice. Just as I thought I was able to slow down in researching it's just keeps going on,lol I do want a safe and reliable system for sure. Thanks!

solarhungry · July 2017

@Raj174,
Thanks for the info, you saved me so major troubles. Much thanks! My understanding of Max amps of the Classic of taking the amps of the panels to not exceed 96 amps was off on my understanding process. I watched the video on midnite's solar channel explaining the String Calculator that you mentioned and also played around some on their website. I have to go outside tomorrow and make sure I have the PV Module Data correct. I saw the 1300 watt max at 12v battery bank. I was hoping for more but guess it is just that way. Looks like it doubles the watts if I go with the 24V battery and panels. Around 2700 watts if I had the info in correctly...but will double check tomorrow on the sticker spec on the panels.
So if I go with the 24V inverter/battery setup it appears that I will have to use 3 midnite solar classic 150 to use all my 6K panels.

solarhungry · July 2017

Thanks for your concerns with the inverter post. I am taking it in. As far as the older 1500 HFT inverter I know it's not ideal for this solar but I'm going to have to try and use it for now on small stuff till I get a real one. The only thing we used it was to charge some weed wacker batteries and an ebike battery on the truck. Maybe old tech but it has always had that smell from day 1. I even got another exact one because one of the guys reversed the wires and burnt out the first one and the 2nd one smelled the same. They don't offer that model anymore. And the Jupiter 5000 watt I'll be caution and not overload it. On HFT website it does say it is UL. And after this I went looking online and found others saying the same that a manufacture making such a high wattage shouldn't be.

Raj174 · July 2017

solarhungry said:

@Raj174,
Thanks for the info, you saved me so major troubles. Much thanks! My understanding of Max amps of the Classic of taking the amps of the panels to not exceed 96 amps was off on my understanding process. I watched the video on midnite's solar channel explaining the String Calculator that you mentioned and also played around some on their website. I have to go outside tomorrow and make sure I have the PV Module Data correct. I saw the 1300 watt max at 12v battery bank. I was hoping for more but guess it is just that way. Looks like it doubles the watts if I go with the 24V battery and panels. Around 2700 watts if I had the info in correctly...but will double check tomorrow on the sticker spec on the panels.
So if I go with the 24V inverter/battery setup it appears that I will have to use 3 midnite solar classic 150 to use all my 6K panels.

I think the important thing to look at is not so much the wattage,over paneling is ok, but the VMP voltage input needs to be high enough to charge the batteries yet not so high as to send the CC into hyperVOC. That would mean a two 300 watt panel series configuration charging a 24 volt bank. In that light, two classics, each with it's own 3000 watt array, would be the optimum configuration. This setup would call for each array to be configured to 5 strings of 2 panels each. Although, they will be slightly over paneled, the average production for each array would be 2200 to 2400 watts on a normal day with losses due to heat.

Now the issue comes to battery size. The arrays will produce about 170 charging amps at 24 volts on really good sunny days, so the 24 volt battery bank will need to be a minimum of 1300AH. The current 12 volt bank at 2300AH would certainly need to be modified. An expensive endeavor as batteries are not cheap. Reducing array wattage may be an option to consider also.

Rick

Estragon · July 2017

I have to disagree with Rick on the bank size. It should be sized based on loads and desired days of autonomy. You can limit charging current at the controller if need be, so there's really no minimum required battery capacity. The limitation is really the maximum size that can reasonably be supported by available charging sources

Raj174 · July 2017

@Estragom
Of course you are correct, I was assuming the OP wanted to use the maximum power available up to a 13% charge rate. Thank you for the correction. And I agree, the OP should be made aware of all possible options.

Rick

Solar Equipment location and inverter wire length

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