Look at my solar system pics and help me finish the project (:

[hollywoodtoday]

What!?

What in the world! You want to close a thread because someones asking questions on a forum????

And please tell me whats so dangerous about my setup? Nothing! Im at a loss for words. Troll? Am I made of time?

I think its pretty plain to see that Im looking for suggestions to a project Im working on bud. I've listened to much of what you guys have mentioned, but some of the things are just not in the interest of my grandfather, however other things are, like the thoughts above.

[Living Large]

What in the world! You want to close a thread because someones asking questions on a forum????

And please tell me whats so dangerous about my setup? Nothing! Im at a loss for words. Troll? Am I made of time?

I think its pretty plain to see that Im looking for suggestions to a project Im working on bud. I've listened to much of what you guys have mentioned, but some of the things are just not in the interest of my grandfather, however other things are, like the thoughts above.

What they are telling you is that you are not following their advice. They told you to stop buying stuff and get the advice of a professional. You are forging ahead, and you desperately need a professional - here is exhibit A:

"I thought of using the air conditioning ac disconnect because its easy to get at home depot, is very cheap and will do as good of job as an expensive throw switch. Using it for dc instead of ac is the only thing I dont know, but not too worried as long as it conducts lol."

You say the AC disconnect will do the same job as an expensive throw switch, yet you say you don't know what difference it makes to use an AC disconnect versus a DC one. And you throw in "lol" almost like it is a joke and doesn't matter even if it isn't appropriate.

I think people are afraid you're going to hurt yourself, someone else, or burn your house down. There are some forums, like HVACTalk, where professionals will not even answer DIY questions. The beauty of this forum is you have people in the industry and experienced DIYers who know how to do the job right. They aren't going to get involved in something that appears to be a Rube Goldberg. Just my .02 as an observer.

[SunEagle]

What in the world! You want to close a thread because someones asking questions on a forum????

And please tell me whats so dangerous about my setup? Nothing! Im at a loss for words. Troll? Am I made of time?

I think its pretty plain to see that Im looking for suggestions to a project Im working on bud. I've listened to much of what you guys have mentioned, but some of the things are just not in the interest of my grandfather, however other things are, like the thoughts above.

Asking questions is perfectly fine in a fourm, athough while you have asked questions, you (or your grandfather) have ignored a lot of our directions which were given to help you build a "safe" system.

Based on your statements concerning wiring and switches I feel you do not know what you are doing and if you continue to do as you want I am afraid you or others may get hurt. Please stop what you are doing now and get help from a qualified electrician.

[J.P.M.]

Third time and out: Some folks you just can't reach.
Or, maybe the poster is just screwing with our collective head and we've been had. In either case, maybe it's time to cut losses and move on.

[Amy@altE]

What in the world! You want to close a thread because someones asking questions on a forum????

And please tell me whats so dangerous about my setup? Nothing! Im at a loss for words. Troll? Am I made of time?

I think its pretty plain to see that Im looking for suggestions to a project Im working on bud. I've listened to much of what you guys have mentioned, but some of the things are just not in the interest of my grandfather, however other things are, like the thoughts above.

You have not listened to our advice. We are trying to keep you from harming your grandfather. You cannot use AC equipment for DC. DC is harder to break than AC because it never crosses 0V like AC does, and unless it is designed to do it, it will not properly protect the line and is very dangerous. The fact that you are insisting there is nothing dangerous about your system proves that you are not listening to us. You just provided a link to a professional solar company. Why will you not call them? It's free to talk! It's what they (we) do. And please listen to what you are told. DC equipment costs more than AC for a reason, so stop trying to take the cheap, unsafe way out.

[Amy@altE]

Thanks for the thoughtful ideas, specially the ones above lol, and yes things are coming along great.

So heres my system to update you: 24x280w panels, 4 tied in series to provide 96 volts. Since I have 2 poles, Ill have 12 panels on one pole and 12 on another. We ended up running 8 12guage automotive wire for each 4 panel setup, 4 pos and 4 neg.

Anyway, I've bought 2 80/80 outback controllers and now am looking for you thoughts on 2 things:

(:

4 of your panels in series will blow up your charge controller. The Voc of the panel is 44V x 4 in series is 176V, not 96V. The charge controller can handle up to 150V. CALL A PROFESSIONAL. Blowing up the equipment and possibly the house is not in the interest of your grandfather.

[hollywoodtoday]

Awesome, good info. Thank you!

You have not listened to our advice. We are trying to keep you from harming your grandfather. You cannot use AC equipment for DC. DC is harder to break than AC because it never crosses 0V like AC does, and unless it is designed to do it, it will not properly protect the line and is very dangerous. The fact that you are insisting there is nothing dangerous about your system proves that you are not listening to us. You just provided a link to a professional solar company. Why will you not call them? It's free to talk! It's what they (we) do. And please listen to what you are told. DC equipment costs more than AC for a reason, so stop trying to take the cheap, unsafe way out.

Gotcha, yes, I recognize that DC rated units must be built a little different. I just figure that since weve used ac breakers on our previous system which has lasted 20 years, I now dont know if its such a big deal, at least for a small system. As far as these 2 disconnects I was going to use instead of a throw switch, these disconnects are rated for 60a and ill only be putting 30a into them. Theyre also just a basic metal to metal switch and since they are fusible I figure it would just be easiest to use it instead. Ill look into that more tho.

1. So could I just run 4 sets of 3x280w panels in series to 1 fuse? Or would it be smarter to run each set to its individual 15a dc breaker? I was going to use some fuses, but now Im thinking of running each series setup into a dc breaker, Im just not sure where to get a box for dc. So Im on the look out too. Thank you for the insight.

4 of your panels in series will blow up your charge controller. The Voc of the panel is 44V x 4 in series is 176V, not 96V. The charge controller can handle up to 150V. CALL A PROFESSIONAL. Blowing up the equipment and possibly the house is not in the interest of your grandfather.

1. Great, thanks, I gave our panel supplier a ring and he said they were 24v nominal panels, so I could run 3 in series and not 4. So Ill simply change up what wires Ive got run and voila.

2. Do you think 3x280w panels in series would be happy with 3 12 gauge wires to the pos and 3 12 gauge wires to the neg, then run 70 feet? That would be 72v all the way underground to the breakers and controller. Maybe I should use 4 or 5 12 gauge for each pos and neg. YES, I know its a wild setup, but there are several people doing things without others input which is why Im here asking to verify if theyve got things correct. So please dont shoot me.

[sensij]

Ok, let's try a different approach. If you don't have full control of the installation (it sounds like you don't), even getting the "right" answer to the limited questions you are asking will still not result in a successful outcome. All you are doing with the feedback here is enabling the bad practice by others. If you really want this to work, maybe a strategy to consider would be to step away from the installation completely. Let these others who you can't control do it their way, and when something burns up, you can be ready to step in and start over. Spend the time between now and then learning how to do the system right (hint, it will be grid-tied, probably with a generator to cover in the event of an outage if you need it, not batteries).

Based on the way money is getting thrown away, there must not really be a budget for this, so no harm done when you start from scratch later, as long as someone doesn't get hurt when it fails.

[inetdog]

Gotcha, yes, I recognize that DC rated units must be built a little different. I just figure that since weve used ac breakers on our previous system which has lasted 20 years, I now dont know if its such a big deal, at least for a small system. As far as these 2 disconnects I was going to use instead of a throw switch, these disconnects are rated for 60a and ill only be putting 30a into them. Theyre also just a basic metal to metal switch and since they are fusible I figure it would just be easiest to use it instead. Ill look into that more tho.

1. So could I just run 4 sets of 3x280w panels in series to 1 fuse? Or would it be smarter to run each set to its individual 15a dc breaker? I was going to use some fuses, but now Im thinking of running each series setup into a dc breaker, Im just not sure where to get a box for dc. So Im on the look out too. Thank you for the insight.




1. Great, thanks, I gave our panel supplier a ring and he said they were 24v nominal panels, so I could run 3 in series and not 4. So Ill simply change up what wires Ive got run and voila.

2. Do you think 3x280w panels in series would be happy with 3 12 gauge wires to the pos and 3 12 gauge wires to the neg, then run 70 feet? That would be 72v all the way underground to the breakers and controller. Maybe I should use 4 or 5 12 gauge for each pos and neg. YES, I know its a wild setup, but there are several people doing things without others input which is why Im here asking to verify if theyve got things correct. So please dont shoot me.

You are making a common mistake when talking about panel voltages. There are two important voltages to know when configuring a series string, Voc and Vmp.
When operating, the voltage on the panel terminals will range somewhere between Voc and Vmp unless you are using a PWM Charge Controller.
If you are using a PWM controller, the voltage at the input terminals is going to be not more than a volt or two above the battery voltage under charge. Pretty much guaranteed to be less than Vmp. A PWM controller will waste any power corresponding to a higher voltage than that of the PWM input.

Because of that a panel designed for battery charging using a PWM controller will have the lowest voltage possible that will work well with any PWM controller.
That means that the Vmp will be 2 or 3 volts above the highest voltage the battery will charge at. For a 12 volt battery, Vmp will typically be 18 volts for such a panel, but the panel is called a 12V nominal panel.
A panel designed for use with a PWM CC and a 24V battery bank will have a Vmp of about 36 volts, and will be called a nominal 24V panel. Voc will be about 1.2 times Vmp, i.e. 44V, for silicon panels

So when you multiply the 24V figure by the number of panels in a string you are seriously underestimating the string voltage.

[Amy@altE]

Thank you for calling a professional. Did you ask them about the rest of the design, or do they just sell panels?

When they said it is a 24V panel, that is nominal, not actual voltage, it says it puts out enough voltage to charge a 24V battery bank, which is 36Vmp. 3 in series will be putting out 108Vmp, not 72V. I can't tell you how many 12AWG strands to use, as it is not the right way to do it. I suggest you get a Midnite PV6 for each pole, install it at the pole, with 4 15A DC breakers in each box, one breaker for each string. That will combine the 4 parallel strings of 3 in series to one combined output per string, and will give you over-current protection, and a way to disconnect the array. The output from each PV6 at each pole will be 108Vmp 33.12A Isc. Each one of these pairs will go to its own FM80.

Do not buy an AC switch for DC, fused or unfused.

[Living Large]

Gotcha, yes, I recognize that DC rated units must be built a little different. I just figure that since weve used ac breakers on our previous system which has lasted 20 years, I now dont know if its such a big deal, at least for a small system. As far as these 2 disconnects I was going to use instead of a throw switch, these disconnects are rated for 60a and ill only be putting 30a into them.

I've never seen an exception such as you describe in any code or specification. There are DC boxes available online on multiple sites.

[Amy@altE]

I suggest you get a Midnite PV6 for each pole, install it at the pole, with 4 15A DC breakers in each box, one breaker for each string. That will combine the 4 parallel strings of 3 in series to one combined output per string, and will give you over-current protection, and a way to disconnect the array. The output from each PV6 at each pole will be 108Vmp 33.12A Isc. Each one of these pairs will go to its own FM80.

Please read the manual for the Midnite Combiner Box. You can use the MNPV6 with 4 breakers in it. http://www.midnitesolar.com/pdfs/MNPV2-3-4-6_manual.pdf

[hollywoodtoday]

Again, to update, my system is a 12x280w/24v nominal system on one pole then the same system on a second pole. So 24x280w panels in all. With 2 mppt classic 200v controllers and 1 12000w 120/240 aims inverter.

You are making a common mistake when talking about panel voltages. There are two important voltages to know when configuring a series string, Voc and Vmp.
When operating, the voltage on the panel terminals will range somewhere between Voc and Vmp unless you are using a PWM Charge Controller.
If you are using a PWM controller, the voltage at the input terminals is going to be not more than a volt or two above the battery voltage under charge. Pretty much guaranteed to be less than Vmp. A PWM controller will waste any power corresponding to a higher voltage than that of the PWM input.

Because of that a panel designed for battery charging using a PWM controller will have the lowest voltage possible that will work well with any PWM controller.
That means that the Vmp will be 2 or 3 volts above the highest voltage the battery will charge at. For a 12 volt battery, Vmp will typically be 18 volts for such a panel, but the panel is called a 12V nominal panel.
A panel designed for use with a PWM CC and a 24V battery bank will have a Vmp of about 36 volts, and will be called a nominal 24V panel. Voc will be about 1.2 times Vmp, i.e. 44V, for silicon panels

So when you multiply the 24V figure by the number of panels in a string you are seriously underestimating the string voltage.

So if our panels will range between 36-45v according to the specs here http://prntscr.com/5oyx6l , this means hes way off. Yet they sell lots of this models and tech support. He said he knew the differences and that these panels would be perfect for the setup.

UPDATE, we are not using 2 outback 80/80 controllers. We bought 2 of these classic 200s http://www.solar-electric.com/misocl...K94BoCWOfw_wcB
sorry for the misinformation.

4 of your panels in series will blow up your charge controller. The Voc of the panel is 44V x 4 in series is 176V, not 96V. The charge controller can handle up to 150V. CALL A PROFESSIONAL. Blowing up the equipment and possibly the house is not in the interest of your grandfather.

UPDATE, we are not using 2 outback 80/80 controllers. We bought 2 of these classic 200s which is good for 200VDC and will be running 4x280w in series with this --> http://www.solar-electric.com/misocl...K94BoCWOfw_wcB
sorry for the misinformation.

Thank you for calling a professional. Did you ask them about the rest of the design, or do they just sell panels?

When they said it is a 24V panel, that is nominal, not actual voltage, it says it puts out enough voltage to charge a 24V battery bank, which is 36Vmp. 3 in series will be putting out 108Vmp, not 72V. I can't tell you how many 12AWG strands to use, as it is not the right way to do it. I suggest you get a Midnite PV6 for each pole, install it at the pole, with 4 15A DC breakers in each box, one breaker for each string. That will combine the 4 parallel strings of 3 in series to one combined output per string, and will give you over-current protection, and a way to disconnect the array. The output from each PV6 at each pole will be 108Vmp 33.12A Isc. Each one of these pairs will go to its own FM80.

Do not buy an AC switch for DC, fused or unfused.

Thank you, ya he said 24v nominal. Shesh, who knows what there talking about! lol. Thats what I was trying to tell everybody, but I dont know to begin with. So you're saying 2 guys at sunelec.com are prob wrong? These panels will be pushing more like 36x4vmax with 4 in series, not 44.9x4? Anyhow, I think running 4 280w in series should be ok to use with 1 classic 200 controller. you think?

In addition, we also have 8 6v batteries like this--> http://www.atbatt.com/trojan-l16e-ac...1a2RoCurvw_wcB

--

With all that said, thank you for your thoughts, much appreciated.

[inetdog]

Do not buy an AC switch for DC, fused or unfused.

+1
An AC rated switch can withstand DC of the same voltage just fine, and can serve as a disconnect IF you can guarantee that it will never be opened under load (that is with current flowing.
A battery voltage DC, like 12V, will not be as likely to sustain an arc when you open it under load, but a string of three 44Voc panels certainly will. All it takes is the switch being opened under load one time too many (which might end up being exactly one time) to cause an arc which could burn you or set the panel it is in on fire.
The danger is even greater after the combiner where you have a higher current in addition to the high voltage.

Similarly do not use AC or automotive (low DC voltage) fuses and fuse holders for high DC voltages. They can catch fire too, as well as not interrupting the fault current in the first place.

[Amy@altE]

Again, to update, my system is a 12x280w/24v nominal system on one pole then the same system on a second pole. So 24x280w panels in all. With 2 mppt classic 200v controllers and 1 12000w 120/240 aims inverter.


So if our panels will range between 36-45v according to the specs here http://prntscr.com/5oyx6l , this means hes way off. Yet they sell lots of this models and tech support. He said he knew the differences and that these panels would be perfect for the setup.

UPDATE, we are not using 2 outback 80/80 controllers. We bought 2 of these classic 200s http://www.solar-electric.com/misocl...K94BoCWOfw_wcB
sorry for the misinformation.


Thank you, ya he said 24v nominal. Shesh, who knows what there talking about! lol. Thats what I was trying to tell everybody, but I dont know to begin with. So you're saying 2 guys at sunelec.com are prob wrong? These panels will be pushing more like 36x4vmax with 4 in series, not 44.9x4? Anyhow, I think running 4 280w in series should be ok to use with 1 classic 200 controller. you think?

In addition, we also have 8 6v batteries like this--> http://www.atbatt.com/trojan-l16e-ac...1a2RoCurvw_wcB

OK, first, your supplier is telling you what we've been telling you since page one of this post. I am now officially losing sleep over this project with worry. I'm going to start again. Why is your supplier not doing this for you?

The panels are NOMINAL 24V, as we have all been telling you, including the 2 guys at SunElec. What that means is that it can charge a 24V battery bank. You will never see 24V coming out of the panel, that is just a category, like a 12V panel (which puts out 17V to charge a 12V battery). The Open Circuit Voltage, which is the output when they are not connected to anything is 44.9Voc. When it is connected to the charge controller, it is outputting the Max Power Voltage 36Vmp, because having a load on it (the charge controller) pulls the voltage down.

By getting a 200V charge controller with the Midnite Classic, you now have to deal with higher voltages than the standard DC equipment is designed for. So yes, you can do 3 parallel strings of 4 in series, but now you need high voltage breakers going into the charge controller. You need 2 Midnite MNPV6-250 combiner boxes and 6 MNEPV15-300 breakers that are capable of handling the 200V. Each pole will have 1 combiner box and 3 breakers. You also need 6 2-hole strain reliefs to get the wires into the combiner box, and 2 1-hole strain reliefs to get the ground wire into the box. Be sure to ground the metal frames of the solar panels, the metal racking, and bring the ground into the combiner box and underground back to the DC switch, charge controller, and inverter. I suggest a lightning arrestor in each combiner box as well, like the Midnite MNSPD-300-DC.

Near the charge controller, you can do a SquareD HU362RB unfusible 3-pole DC disconnect.

At the output of the charge controllers, you need 100A DC breakers going to the batteries. They can be regular DC breakers now, because you are at the output of the charge controller at the 48V battery bank. Midnite MNEDC100, you need 2, one for each charge controller.

At the DC input of the inverter, you need a 400 Amp DC fuse like http://www.xantrex.com/power-product...se-holder.aspx

I am not familiar with your inverter, as we don't carry them. Read the manual, it will tell you how to connect it to an AC power source like the grid to charge up the batteries. I believe it also has an internal auto transfer switch. You will need AC breakers at the AC input and AC output of the inverter. http://www.aimscorp.net/documents/PI...K%20Manual.pdf