Help: Need Solar installation diagram that follows NEC guidelines

Hello everyone! I have been on this blog for a long time now and more of a shadow figure trying to learn solar as much as i can. Previously i have asked questions and managed to receive great answers and so I am back again for more!
I am interested in looking at a detailed installation diagram for a solar off grid system. I am trying to learn exactly where, how and why each and every component will be installed. I know it seems like a big ask but i am genuinely interested in knowing this because here in my country we have lots of scams when it comes to system design and its components.
I know a general guideline that is Solar panel > Combiner box > Charge Controller > DC Breaker > Battery bank > DC Breaker > Inverter > AC Breaker > Load
However, i do not know the precise method in calculating all the requirements. if anyone here can post a diagram along with rules and calculation methods, i will be truly thankful to that person.
Hope to hear from you guys soon.
I am interested in looking at a detailed installation diagram for a solar off grid system. I am trying to learn exactly where, how and why each and every component will be installed. I know it seems like a big ask but i am genuinely interested in knowing this because here in my country we have lots of scams when it comes to system design and its components.
I know a general guideline that is Solar panel > Combiner box > Charge Controller > DC Breaker > Battery bank > DC Breaker > Inverter > AC Breaker > Load
However, i do not know the precise method in calculating all the requirements. if anyone here can post a diagram along with rules and calculation methods, i will be truly thankful to that person.
Hope to hear from you guys soon.
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http://www.outbackpower.com/wiring-diagrams
And so does Midnite:
http://www.midnitesolar.com/documentsA.php?menuItem=admin&docCat_ID=4&docCatName=Wiring Diagrams
For sizing, it is much easier (the first time) if we design the system to your (estimated) needs/system sizing. Seeing it done once, will give you a good idea how to design other systems later.
Small system designs are "different" than large system designs (VW Bugs are different than Diesel Trucks)--But the basics are similar.
-Bill
1. Energy saver light bulbs: 30 Lights rated at 14 watts each running for an average of 10-12 hours a day
2. Ceiling Fans: 12 fans rated at around 80-100 watts each running for almost all day for 8 months a year
3. Laptops: 5 Macbook Pro
4. Phone Chargers: 5
6. LED TV: 4 TV's; 42 Inch; running for around 8 to 10 hours a day (LED TV with wattage of 70 watts each roughly)
7. One Router
So these are pretty much the items I would like to use on solar.
Hope this much info is adequate.
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
2,000 Watts * 12 hours per day = 24,000 Watt*Hours = 24 kWH per day = 720 kWH per month (that is tyical sized western home power usage).
Assuming 2 days of storage and 50% maximum discharge (for longer battery life), a typical full off grid system would need a battery bank of:
- 24,000 WH per day * 1/0.85 inverter eff * 1/48 volt battery bank * 2 days storage * 1/0.50 max discharge = 2,353 AH @ 48 volt battery bank
Next, calculate the size of the solar array. First, based on minimum charging rate for battery bank and second based on hours of sun per day. You can use 5% to 13% for typical solar charging of a battery bank--However, for full time off grid, would suggest minimum of 10% rate of charge. And if you are running loads during daytime, you have to add additional solar panels to support daytime loads too:- 2,353 AH * 59 volt charging * 1/0.77 panel+controller derating * 0.05 rate of charge = 9,015 Watt array minimum
- 2,353 AH * 59 volt charging * 1/0.77 panel+controller derating * 0.05 rate of charge =18,029 Watt array nominal
- 2,353 AH * 59 volt charging * 1/0.77 panel+controller derating * 0.05 rate of charge =23,438 Watt array "cost effective" Maximum
- 2,000 Watt load * 1/0.77 panel+controller losses = 2,597 Watt array to support day time loads
- 18,029 Watt array (nominal)+2,589 Watt load support = 20,627 Watt array minimum recommended (based on battery AH capacity)
And then based on fixed array in Karachi, tilted to latitude facing south:http://solarelectricityhandbook.com/solar-irradiance.html
Karachi
Measured in kWh/m2/day onto a solar panel set at a 65° angle:Average Solar Insolation figures
(For best year-round performance)
So... The minimum array you could get away with is around 10,000 Watts--And if you want a "robust" system (fewer battery charging problems, longer battery life, and less genset runtime), you could justify upwards of a 20,000 Watt array.
-Bill
1. Can you elaborate the 2353 Ah @ 48 Volt figure into how we can choose the number of batteries?
2. I have read that the manner in which you interconnect batteries affects the charging performance. Is that true?
3. I have read that DC breakers are sized at 1.25 times the needed Amperage; are there any other factors I need to keep in consideration when sizing DC breakers?
4. If the input current into the charge controller is so high that one controller can not suffice then how can you add add and interconnect multiple controllers together to cater for the amperage.
5. Since this 48 Volt system needs 59 volt of charging, does that mean I have to interconnect panels in a manner that the controller receives a minimum of 59 volts as input?
6. I have read that not all panels output efficiently which causes problem with mppt of a string. does that mean having mico sized controllers on each panel is better that to have multiple large controllers?
7. is there a reliable wire sizing chart that I could possibly use? i seem to come across conflicting charts at times and not sure which one is true.
8. which batter would work best for solar? AGM or Lithium Ion. Considering that a region has power failure almost every other hour. Is there any informational site that lists down which battery works best for a particular use?
For now these questions have been bothering me for so long that I am always confused. I would really appreciate clear answers. Thank you guys for taking time in replying once again.
http://forum.solar-electric.com/showthread.php?5556-Working-Thread-for-Solar-Beginner-Post-FAQ
Hope this helps.
-Bill
http://zoneblue.org/cms/page.php?view=off-grid-solar
You should have included how much money you can spend on this.
Get a copy of NEC 2014. Big changes between 2011 and 2014 as far as solar stuff goes.
Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.
Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
while it doesnt apply to some offgrid folks......some will want to follow NEC for insurance purposes
lets face it...in the past ...the NEC gave some stupid rules for renewable systems.....these changes are supposed to address some of the more stupid ones
But for the DIY person (or in my case only DIYed the engineering / plans part) installing off-grid or installing in a place that does not have inspections for solar, using this will at least make sure your wires don't burn or that you don't lose too much to wire resistance (especially between charge controller and battery) this set of calculators work great (the site sells electrician certification classes but the calculators are free without hassles):
http://www.electriciancalculators.com/
Oh also, most electricians (and many engineers and inspectors) don't pay attention to ambient temperature adjustments or adjustments due many current-carrying wires within a conduit (such as wires from 4 strings of solar panels sharing a conduit right on the roof to reach a combiner box that the electrician wanted to install in the shade, which makes sense - sun-struck things have much shorter lives). These calculators make it easy to pay attention to those things. Not only you actually achieve the excess safety margin that the NEC aims to achieve (because they know some things will be overlooked or corner-cut), but you also get less losses especially when your wires are running for 50, 100, or more feet.
For firefighters - they run on a rule of thumb - if they don't think it safe to enter an area (batteries and energized PV), they just let it burn. Part if not most of the reason of the rapid disconnect bit in the NEC 2014. My system cannot comply with NEC 2014 without major changes because the combiner boxes are installed about 2/3 of the wire-travel distance from PV to charge controller. So even if I bought Midnite Solar's birdhouse disconnect kits, it wouldn't help because they shutdown at the combiner box, which are normally installed very close to the PV source. My system splices each string to #6 and takes the #6 through the attic to the combiner box and then it comes out of the combiner at #2
Y....A....., regarding the part about MidNite, Where is the data on this?
Seems disparaging to me, without some concrete, verifiable reference to this.
Otherwise, why not remove it? Thanks, Vic
http://www.mikeholt.com/nec-history-and-purpose.php
Distributed power--Whether solar panels or large banks of batteries--Is not a simple task to make for a "safe" installation.
-Bill
http://www.pbase.com/greatinca/solar&page=all
htps://offgridsolar1.com/
E-mail [email protected]