Source for 6 or 8 awg

[breamer]

Could I go to Home Depot and use the wire that is sold there?  Does it have to be braided or solid.  I don't have a local source for PV wire

[SteveCH]

I buy 6 and 8 ga. at Home Depot and/or Lowe's. The prices in my area are usually the same. Stranded or solid...depends on what you are using it for. My uses are for wiring PV panels and etc. and I find mult-stranded much easier to work with. Note: I am not an electrician but a homeowner with an owner-built and maintained PV system.

Anyhow, I have found no source of wire any less expensive than the big box hardware stores. Keep an eye on the end-of-wire-spool and returned wire. At the stores I frequent, talking HD and Lowe's, they often have a selection of odd-length wire for half price. I found a 20' length of 6-ga last month and the clerk wrote it up for $2.

[breamer]

This is to extend my 1.6 kw system.  I have a run of 75'.  The panels are 160 watt,    
19.91V (not open circuit), so a 10% loss still yields 17v at the controller.  So even on a cloudy day I should still be over 14.4 V with 10 awg.  The panels are 160watt 12v, 10 amps

Additional thoughts?

[XeonPony]

stranded is better for dc, and you want largest guage you can afford, welding shops or good auto shops will have good heavy guages.

[Frank S]

 My 1.1 KW system is 60 ft from my charge controller . I have 10 ga PV wire comming out of the panels then to a 10 AWG THHN stranded wire extender to reach the combining terminals from there I ran 2 AWG THHN stranded to my charge controller.
  I could have ran 4 or 6 AWG but there were 3 reasons why I elected the heavier wire #1 Most important I already had this wire
#2 if I need to move my array further away I can extend the 2 AWG a much longer distance than I could have with a smaller gage.
#3 should I increase the size of my array the wire will handle the added load.
 even iv I go up to a 6KW or larger system  if I go to 48v this can still serve as the trunk line plus I still have 400ft of the 2 AWG  for future expansion

[fabricator]

You can buy huge aluminum for 1/4 the price of copper. The power to your house is likely carried on aluminum.

[WindriderNM]

Metal salvage yards are a good place to get wire. You can usually get for slightly more than the scrap price.

[Frank S]

Metal salvage yards are a good place to get wire. You can usually get for slightly more than the scrap price.

Yes I bought 40ft of 500MCM for $126.00  that worked out to $3.15 per ft couldn't have bought #000 at a box store for that

[SparWeb]

Yeah I only start at Home Depot for the chance to look at the cable, maybe measure if it will fit the conduit, read the specs, and learn the "retail" price.
Then I go to a wholesaler and buy for 1/2 the price!

If this helps:
I just bought 200' of NMWU 8/3 for 330$ and 300' of NMD90 12/2 for 120$ (Canadian dollars).  I'm sure somebody can find it cheaper but it's already a win for me because Lowe's NMWU rolls were priced twice as much for half as long!  The NMD90 was nearly the same but still cost more.

At these gauges the conductors should always be multi-stranded.
I am uneasy buying salvage cable.

I once bought 150 feet of 4/3 aluminum armoured cable (called "Teck") for about 350 dollars.

[tecker]

Stranded manages the best solder the ends and use Noalox or some other anti-oxidant

[Frank S]

One thing I never do is buy multi conductor cable  except for making extension cords then it is always not less than 10/3 w ground and sometimes 10/4 with ground when I can't find 10/2+8 with ground very hard to find that one 
 I can't stand the ignorant American split phase current and will never fully understand the real reason why it still exists
 I don't care for aluminum wire unless it is copper clad and would never use aluminum wire for anything other than open air feeder lines
  All my wiring is done in conduit preferably non conducting when ever feasible
 But that is just me 

[canadian REDNECK]

stranded is better for dc, and you want largest guage you can afford, welding shops or good auto shops will have good heavy guages.

Yes, thick is better but the stranded for dc thing is a myth.
Talk to a engineer or electrician that works with dc and they will tell you that that only applies to dc conductors over 2.5 inches in diameter.
Stranded wire is only easier to work with.

[canadian REDNECK]

stranded is better for dc, and you want largest guage you can afford, welding shops or good auto shops will have good heavy guages.

Yes, thick is better but the stranded for dc thing is a myth.
Talk to a engineer or electrician that works with dc and they will tell you that that only applies to dc conductors over 2.5 inches in diameter.
Stranded wire is only easier to work with.

[Frank S]

stranded is better for dc, and you want largest guage you can afford, welding shops or good auto shops will have good heavy guages.

Yes, thick is better but the stranded for dc thing is a myth.
Talk to a engineer or electrician that works with dc and they will tell you that that only applies to dc conductors over 2.5 inches in diameter.
Stranded wire is only easier to work with.

 Yeah try using a #0000  solid conductor as a welding lead or even  THHN for that mater not many EEs do much welding apparently 

[phil b]

Stranded wire is normally used where vibration is present.  (look under the hood of your car.)

The exception is large cable, which is almost always stranded. Otherwise, you couldn't bend it without using brute force.

I looked at Home Depot and Lowes to find the little copper boots or thimbles that go on the end of the naked stranded wire for breaker box use. They will keep the stranded wire from spreading out or breaking under the breaker or neutral screw.

Since the electrical wire on all my wind generators have been ran inside the pole, I have always used stranded electrical extension cord. Home Depot and Lowes carries 10 AWG extension cord for about 150 bux per one hundred feet. Check Harbor Freight too. They have some good extension cord that's usually cheaper than the other big box stores. 

[dnix71]

http://www.ebay.com/itm/100-50-ft-50-RED-50-BLACK-8-Gauge-AWG-Power-Wire-Cable-Stranded-Copper-/271309884146?pt=US_Car_Audio_Power_Speaker_Wire&hash=item3f2b544af2

Buy 2 and splice in the middle. Free shipping.

[Mary B]

I use #6thhn for the 120 foot run from my panels to the charge controller. Running 92 volts at ~12 amps or so maximum. Keeps the voltage drop tolerable.

[trbarto]

I think you got some bad information...I AM an engineer, and my recollection and understanding of current - is that it travels only along the surface of a conductor.  So stranded wire offers allot more surface area for current flow than does the same gauge solid wire conductor.

Also - if workability is your concern...I've had luck with running the heavy gauge wire from the power source to a set of terminals or bus bars and the final... say 10-20 feet, that has the most bends perhaps to the charge controller, could be stepped down in guage - so in your case, you'd run 6ga to a final and SHORT length of 8ga...you will likely NOT be able to measure your loss nor heat diff...

[DamonHD]

So far as I am aware the 'skin effect' only applies to (relatively high-frequency) AC, else current is carried through the entire body of a conductor.

Rgds

Damon

[Mary B]

I agree Damon, all my RF teaching shows the higher the frequency the greater the skin effect.