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For an off grid solar project, you will need to pickup the following items

  • Inverter, Modules, Battery and Charge Controller.
  • 12 or 10 awg THNN or THWN wire stranded Red, White, Black and some Green.
  • A box to combine all the solar panels wire in to two larger wires to hook to the
    disconnect box
  • Water proof box wire connectors (lowes)
  • Out door breaker and box or disconnect and box
  • 6 or 4 awg THNN or THWN wire to connect the combing box to the out door breaker
    box
  • Large wire for Earth Grounds and equipment ground connectors, 6 awg wire minim to
    ground all your solar panels and your equipment.
  • Flex conduit and connectors water proof
  • Indoor Breaker box before the charge controller
  • Charge controller that can handle the amps you are going to be putting on it, MPPT is
    best
  • Large awg wire to the charge controller breaker box and back to the solar panels
    (voltage loss)
  • Second indoor breaker box after the charge controller
  • Same size wire going from the second charge controller breaker to the battery bank
    disconnect switch /breaker / fuse
  • Battery bank disconnect switch /breaker / fuse or one of each
  • Very large wire from the battery bank disconnect switch /breaker / fuse to the batteries
  • Same size Very large wire going from the battery bank disconnect to the inverter.
  • A electrical knowledgeable friend if you are not
  • Voltage loss calculator of some kind to make sure your wires are sized correctly
  • National Electric Code info for your area
  • Battery bank

One of my first solar electric project has 800 watts in panels, so get what you feel you want
or need for your project. Maybe a small roll of each of the following or however many feet
you think you will need, 10 awg THNN or THWN wire stranded Red, White, Black and some
Green. Large wire for Earth Ground wire, Connectors, 6 awg wire minim to ground all your
solar panels and your equipment. Flex conduit about 25 to 50 feet depending on your
requirements for your setup. I have an 800 watt system and have it wired 24 volts so I am
using #4 awg wire to the charge controller and back to the solar panels.

An electrical knowledgeable friend and myself developed a helpful voltage drop
calculator. Using his knowledge of Electric and my 18 years using spread sheets we came
up with a good information product (in Excel format, If you feel like playing with it Voltage
drop Calculator ). It shows that my #4 awg charge controller to panel wires only have a loss
of .014941 volts with a 22 foot wire run round trip. Very much of that and you could have a
full 1 volt loss and with a 12 volt system that is a lot. The larger the wire the better.

Breakers

Out door breaker and box, or disconnect box and disconnect, to put on the solar panel
array. And a box to combine all the panel wires in to two larger wires to hook to the
disconnect box. You need to be able to shut off the power at the solar array. You as well
need a 60 amp breaker and box, DC voltage type maybe from Lowes, hooked in right before
the Charge Controller. Helps when you are working on the charge controller inside and need
to shut down the array. Always shut down the array before you disconnect the battery bank.
If it is a safety matter shut down what ever you need first.

Next in your project you will need to get a charge controller that can handle the amps you
are going to be putting on it.
If you get too small of a charge controller you will just fry
it.
I am living proof of what not to do. “been there done that” I have an MPPT 60 amp charge
control which helps keep the wire size down saving a lot of money. MPPT is best known for
being able to down convert voltage. I have a 24 volt solar array and a 12 volt battery bank.
So a simple way to look at it is you could put 30 amps at 24 volts into the MPPT charge
controller and it will put out 60 amps at 12 volts.

You need to
check the National Electric Code in your area when doing the wiring for
your solar project. To see what they will allow or buy the book which there is not much of a
need for. Your breaker has to be smaller then the wire is capable of handling by a set
percentage. A 12 awg wire normally has a 20 amp breaker in your home. What if you were
to use a 60 amp breaker and your TV shorted out. The wires would get hot and burn down
your home. This is because the breaker can handle more power then the wire. So which
gets hot? Yup the wire and your walls.

On the other side of the charge controller is the battery bank.
You will need some large
wires “size depends on the current flow and how far the charge controller is from
the battery bank.
Get a breaker and breaker box to match your needs here as well. Flex
wire is easiest to work with but the price bites. If the batteries are near to the charge
controller no need for a second breaker or disconnect, a fuse might be handy for just in
case.

Moving on still in DC voltage, You will need to get a 120 volt power inverter for what ever
your voltage is in your part of the world.
I recommend a pure sine wave inverter or you
will have problems with digital clocks and bread makers and maybe some of your office
equipment. Depend on the inverter and wire size put a heavy amp fuse in the wire as close
as you can get to the battery bank. Follow this with 175 or 250 amp DC voltage breaker
disconnect near the inverter. The fuse is not required if you have a breaker. Then attach to
the inverter. Keep in mind that you will be pulling as much as 150 amps and more at times
from the battery bank with a 2000 watt inverter at 12 volts. You will need some heavy wire.
Soft flexible wire is nice here. Ever tried to bend a 4/0 wire? Not easy to get it around
corners or through holes.

Click here for a Solar Power
System checklist by John Wiles, You should print this if you are
planing a do it your self system.

Follow John Wiles Solar check list above and you should have a legal system completed up
and running.
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Stand alone Solar Project

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My solar electric system,
Lets get started building an off grid or what would be called a stand alone solar power
generator. First thing you need to do is source your products. You will need the following list
items and a few more. You can never plan it right and you will never be able to go buy just
the right amount of parts. I have tried and always ended up going back for more. Always
something I forgot or did not know I needed till I seen how the project was really shaping up.
Smart Power M4 Plus Inverter 4kW with SP Monitor 3.0
$4,813.00
05/26/08
Questions?  479-488-6048
XW-6048-120/240-60 48V.
$3,305.25