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#41 [url]

Feb 20 12 4:36 PM

hey man... be very careful when buying those jumper cables or ANY cable from amazon. 

Most of that wire is copper clad aluminum junk!  To make it worse... They say it's 8 or 4 Gauge wire, but in reality it's 12-14!    One hint.  Check the shipping weight.  Copper is very heavy...  So, you should see some heavy numbers like 10-15 lbs for shipping if not it's probably aluminum, if you want 0 gauge alum you can buy that @ home depot or lowes for a buck a foot.

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#42 [url]

Feb 20 12 5:22 PM

If you  put the control panel next to the batteries and run 2 or 3 sets of 2-18 or 2-16 to the cabin it would work. Size the wire to the load max. 2 or 3 runs of house wiring is a lot less than 30 feet of #6 or 8. Use plastic roll water pipe in the ground. you can also put the inverter next to the batteries also if you need a TV or phone charger.
You can also run a 24 volt system and use 12 for lights and 12 for your inverter. You will need to balance them out the best you can. Lights use so little that you could also run a 24 inverter, half the 24 volt current for the same 120 volt output and still use a 12volt leg for lights. You don't have to spend a lot to get a little power.

If you need a voltage controller call me I have a spare or two.


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#44 [url]

Feb 21 12 6:08 PM

I found a great site that gives a break down of what kinds of wire exists and what the letters and numbers stand for; it's a home depot site.

So, the pdf installation file for the Grape panels I'm looking at is located here:

In the left column, under "Specifications" and under "Poly-crystalline PV Modules" if you click on 220W it brings up 2 pdf files and click on "Installation Manual" 

There's all the usual crap, don't fall, don't install in the rain (lol) blah blah...and then on page 7 under
 3.  "Electrical Connections"....."all installations must be performed in compliance with the NEC

and 3.6 says Use cables and wires with adequate cross-sectional areas (min. of 12AWG) and suitable
Multi-Contact interlockable connectors, such as MC-4 connectors which are approved for use at
the maximum short-circuit current of the module.

Then, on page 14 refer to the table, on the row that says CS-P-220-DJ Under the column Short Circuit Current Isc (A) and this 220W solar panel's short circuit current is 8.40 Amps

This website has a really cool description of what a Short-Circuit Current of a solar panel is exactly:

So, I'll look at what NEC says about this...

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#45 [url]

Feb 21 12 6:38 PM

Better yet, this website pretty much explains it all AND warns against using "Romex" altogether and why it's better to use stranded wire.

But, since the Grape Solar rep. said for 2 of these panels there needs to be a 30amp charge controller, I'm assuming there needs to be wire that can handle 30amps and according to the AWG table on the first page this system needs 7awg 

About solid vs stranded wire it says: Almost all wiring is done with stranded wire or cable. Solid wire is occasionally used for long runs, but in most cases it is not suitable for wiring panels, controls, pumps, batteries, or other components. If used, you run the risk of breaking the terminals....etc.

At the very bottom of the page, there's a link to go to their "Wire loss Table"....ok..well....since it's in metric and you have to cross reference, I'll have to come back to it. Anyone else decipher it?

On to a source for 7awg and specs on fuses, breakers and disconnects....yawn

Edit.....edit....edited to add a possible source for 7/2 AWG UF-B !!!!! But, is it stranded? Will call manana. My daughter sent me the link...she's purchased from them before. And how much is shipping to Hawaii...always a big question.  Anyone wanna go halfers?

Edited.....It's specs say either solid or compressed stranded and the shipping is a whopping $114

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#46 [url]

Feb 21 12 7:55 PM

For Wiring purchase...I've decided on Northern Arizona Wind & Sun.  Their website wire page is here:   

They show the NEC Codes related to this wire NEC 340 (for UF or direct burial) required by NEC 690 (for solar array systems) "splainseverathang" and on this page, there's a PDF file that appears to be a draft of  NEC 690!!!!!  How do you spell hallelujah?

I'm calling my librarian tomorrow to see if they have the actual NEC 690 on their shelves.


I placed 30' of 8/2AWG STRANDED wire (discounts for bulk) in my shopping basket and went to my cart to check shipping. At the bottom of the page you put your zip code in and mine came up as UPS ground at $48 and USPS priority at $21.25

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#47 [url]

Feb 22 12 2:24 PM

Say you bought a the above item...   Cut into three equal lengths would give you 30' of cable.  So...

You would have your Stranded cable, 3 #12 wires... you "COULD" ....  I use that term loosely...

Take the ends of all the cables and wrap them together.  Maybe even solder them together or crimp em ... But theoretically for 50 bucks you would have your #8 stranded wire @ 30' long shipped free!

Just a thought I had.


@ 14 lbs I would think it would have some copper in it and it's UL rated so... take it for what it's worth

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#48 [url]

Feb 28 12 8:29 PM

You know what? I think that would work!  What is a bigger gauge (smaller number) wire anyway? More wire stranded together!  I have a friends old batteries and I'm going to try that and see if the two 6v come out at 12v!!!!!

So, I started looking at the kits available at online stores. Even though they are obviously VERY overpriced and most are for 12v solar panels (really rated 17v-21v) and include #12 or #10 wiring which is way too small for the Grape solar panels. But, they atleast include most of the total components necessary under NEC for solar.

Then, I found this guy's blog about his boondocking in an RV.

He shows his system and it's evolution in pretty good detail and I learned alot from it. 

This guy has a blog that is a very long and antagonistic point of view on many particulars of what goes in and what does not go in to a system.  I feel like he pointed me in a great direction. I want to email him, but after reading his blog I really get the feeling he might verbally spank me for not knowing enough.

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#49 [url]

Feb 28 12 8:40 PM

The website has has alot of information

On this page

They show you how to make your own solar combiner box.  So I go to Home Depot to get the Homeline (aka square D) 100amp load center and two 30 amp breakers.  They carry the breakers but not the panels. So, as much as I hated to because they are not at all nice to me in electrical, I asked "what would be the equivalent item that you do carry". 

He said, get ready, I can't help you with that, electrical is very dangerous. So, **** them, I'm ordering whatever I can online.  If I could order thinset online I would.  It's not as though I was asking him for advice. Seriously, you're not gonna believe what happened next.  Two smutty looking guys (I'm smutty looking too) had a bunch of electrical supplies in a basket and they asked if a BR 20amp double pole breaker had been ordered. They guy said it won't be in for a while but you could use this.....and he points to another double 20a.  hmph  That's why I don't like to ask peeps for help in this town.  

I wonder why, if you have to have a license to install electrical in this county, do they sell electrical supplies right on a shelf? Shouldn't they be locked in a case along with cigarettes? lol  

Dangerous plumbing anyone?

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#50 [url]

Feb 28 12 8:41 PM

Solarray signed up and I was hoping he would give you folks a rundown on what he carries. 

He has alot of information and he sells locally.

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#51 [url]

Feb 28 12 9:38 PM

How large of a system are you building??  Most of what you are asking about is for a 20 amp system or larger which is about a  KW. I thought when you started it was lights and small TV.
You should give me a call 9823273 .


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#52 [url]

Feb 29 12 10:58 PM

Having checked out the RV electrical -guy's blog, I was sort of amused by our different respective versions of off-grid freedom. And not to knock his trip but, his starts out with the premise:
...Well, first-off, we just knew we'd want to be able to drive our house all over the continent. And then, of course, we'd need satellite tv, and an (apparently) electric furnace. Did I mention frozen food? Lots. So, naturally, we need our blender for frozen daiquiris...
Whatever, that's his, fine.
Anyway, I'd still suggest that a modest system, and one that infers a sort of renunciation of a certain need for energy can also contribute to...reading some good books...or learning some new songs.
Just a thought that comes to mind.

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#53 [url]

Mar 1 12 9:29 AM

I build a 2.5 KW system and the only thing I need to replace is the refer/ freezer. It uses way to much power, and I have a plan for hot water in the works, but you don't have to have that.
My plan is to use the power co for power to the the hi amp. items until I can replace them or the ship hits the sand then do without. I also built a satellite TV, but Most of the 350 channels are not Eng. I do get the news and some old TV shows if I want. All low power.


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#56 [url]

Mar 4 12 1:31 AM

Yeah I posted a link on the .01Kw per day fridge.  It's actually a freezer with a thermostat to control the compressor to make it stay at 36 degrees.   If you don't want to look for it there you could do a search on google ... .01Kw hour fridge. 

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#57 [url]

Mar 4 12 8:12 AM

Yes, now I am trying to see if I can replace the fridge with a small top open fridge/freezer. I am wondering how to keep ice. Any ideas if and how, the bottom  should be cooler then the top but by how much I don't want to freeze Evey thing. Maybe just a Styrofoam box with ice in it. As a fall back keep cold water in the fridge.


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#58 [url]

Mar 4 12 11:15 AM

There was some sort of technological breakthrough or new construction method or something with refrigerators within the past several years.  Check out how much power a new (less than two years old) mid-sized refrigerator uses.  You may just need a new refrigerator with no modifications at all.  We just got one here for the new house and it is a 21 cubic inch with the freezer on top and the ice maker in the freezer.  That plus the rest of the house uses about $56 of Helco electric each month.  I haven't put a meter on the refrigerator to see how much power it's using.  But there's the small freezer, the computers, the stereo, TV, all the lights are curly bulbs but we use them a lot.  The electric bill has been low enough that we haven't been driven to have the solar panels relocated.

We have just plugged in a hot tub, though,and haven't gotten the first electric bill.  When that shows up, you'll probably hear the scream.  At that point there will be a major scramble to put that thing on solar water heating as well as solar electric, although it's a 220 volt system so it's gonna want to suck a lot of power.  If we take the heater portion off, that should make it a lot less of an energy hog.  Then all we will have to do is figure out the water pump portion.

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#59 [url]

Mar 4 12 3:45 PM

I couldn't figure out why manufacturer's couldn't just mark their panels as 12 volt, 24 volt, 48 volt. 

This website article explains it all:

So, the Grape solar panels are a nominal 18 volts and Solar ray's are 24 volts.

Even though I can get a pwm charge controller and loose a little efficiency I can still charge my 12 volt system and not have to pay for mppt right now. 

I'm still trying to understand the wiring and source it. The arizona company only sells down to 10/2.
Going to call them on Monday and ask why they advice 8/2 but don't sell it. 

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#60 [url]

Mar 4 12 3:48 PM

Does anyone know why you can use 240 volt outlets for dc?  


DC OUTLETS are not standardized. Beware the old RV cigarette lighter plug. They are poor quality, illegal in houses, and will burn. For quality and durable 12 or 24 volt outlets, just use standard 240 volt 20 amp AC outlets. These usually pass code inspection used as DC outlets if there are no actual 240 volt outlets in the same house. They fit the same outlet boxes and same cover plates as regular 120 volt AC outlets, and just as easily attach to wire with a screwdriver. These are listed in our catalog as #O-DC OUTLET and #O-DC PLUG.

To figure the correct wire size to use for 12 and 24 volt DC circuits, use the wire size chart printed with the solar module wiring in our catalog. Generally, use 12 gauge wire up to 35 feet or 10 gauge for runs up to 50 or 60 feet. (Stranded wire and solid wire of the same gauge carry the same ampere rating).

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