About to finish pre-wiring and need to wire for motorized blinds/shades. Which wire should I use?

[Del91574]

Depends on the # of strands and size.  For example he listed 22AWG as 16.14 ohms/1k-ft but 22AWG 7/30 stranded is listed at 14.74 ohms/1k-ft.  That's almost 9% reduction.

WIthout arguing the entire point, the cable construction is very different. Apples to apples, and most times, I doubt people will spend the cash for a high strand count cable vs. solid for 99% of the applications out there. You're talking a cable designed for a high degree of flexibility or for a special application, such as audio, vs. general use. Even on the chart linked, look at the widely advertised differences based on construction details alone.
 
There's also differences between manufacturers and circular mills and even conductor lay, so if the item is that mission critical, it would need to be looked into further, however if you're running close enough where an ohm makes or breaks the power loss calcs, you're choosing the wrong AWG for the application.

 

[Frunple]

Frunple,
 
I think I understand this pretty well.  Just stating that you are correct several times does not make it so...
 
Of course a closed loop is needed for current.  But you misunderstand what I am saying and are making up things you claim are the same.  I could easily measure the drop of one conductor.  Just double the cable back on itself so both ends are at the same place.  Connect the load to one end (using both conductors so current loop is complete) and use a meter to measure the voltage from one end of one conductor to the other end of the same conductor.
 
You could always use a power supply and a load with a known length of known gauge wire and measure the voltage.  That would show who is correct.
 
Or you could look at the google book link given by rocketmonkeys.  On page 398 it states that for an 8 ohm speaker 500 feet from the amplifier connected with #19 wire that half the power would be lost in the wire. 
 
On page 400 of the google book it gives the resistance of #19 wire as 8.1 ohms per 1000 ft (which is about halfway between #18 and #20 on the table given in this thread earlier so the tables agree).  If half of the power is lost in the wire the resistance of the wire must equal the resistance of the load (the 8 ohm speaker).  The resistance for the wire is the value for 1000 ft or twice the end to end length.  The tables list resistance for a single conductor of the given length as I stated before.

And yet it doesn't change the fact that I am right either...
 
Yes you could double back the wire. But why?? the specs are what they are. They are for a 100' run of wire with a voltage drop at the end of that 100'. The only way to measure a drop is by having a source and return.
 
Either way, not gonna waste my time arguing when there's no point. I'm pretty sure the OP knows whats what.