Wire column for residential

[Danegoodwin]

Question. In relation to the AC rule found in 240.4 (g). Since I mostly do residential. I use the 60 degree column for wire running from the interior panel through the residential structure to the disconnect and then 75 degree table for the whip. Does that sound correct? And then am I able to use the chart/ampacity from 240.4 g on residential wire? Or does this rule only apply in commercial setting using THHN?

 

[infinity]

If using NM cable you'll need to use the 60° C ampacity. With THHN in a raceway you can use the 75° C ampacity because all modern terminals are rated for 75°C.

 

[WD40]

I cant ever get a straight answer from an HVAC person on these things.
My boss gives me the specs says they are installing a 2 ton mini split two zone.
OK but whats the MCA? What size circuit?
--Crickets--
So I ask again hey I am doing that job today what does the HVAC guy need?
--Crickets--
I figure well it wont be more than 30 Amps so I pull a 10/2 for 30A disconnect on rough in to get er done.
I do the flex whip on finish out I could use the 75°C terminations but I have had inspectors call me on the el cheapo non-metallic liquid tight pre made whips my boss stocks. It only has a 60°C wet rating, but they come with 10 AWG.
Sometimes the unit shows up and has a MOP of 15 or 20 then I'll use a 12 awg whip and downsize the breaker.