95% of the time you are going to be fine with 2 wire but go ahead and wire with 3 just in case. (unless its a huge money deal or something) Like i said , most units are going to only use 2 wires and a ground but its always good to run the extra wire just in case.
This is basically what I was thinking. For the price difference, might as well run the 3 wire, in case some oddball ac needs neutral/120V for something.
Thanks dude.
Just buy 12/2 with ground a little overkill on wire size but safe
There's already a 12/2 ran for 240V HVAC in the room. I had originally thought it would certainly be enough for the AC needs alone (and maybe even a small dehu, but not alongside a
24000btu ac probably - I wasn't thinking I'd need 24kbtu).
There's a dedicated 240V circuit for lighting. And another 12/2 circuit for whatever (120V equipment, or another 240V circuit, depending what's needed).
I started looking for/at Amperate ratings of 24kbtu split ACs and seeing "30A breaker recommended", and "18A disconnect", and hearing the commonly ran wire gauge being 10awg...
...I was ready to seal things up until this.
from a quick read , it appears you will be no where near 20 amps with a unit that big. I dont know exactly how it adds up but it wont be more then 12/2 is rated for.
From experience , i cant see it drawing more then about 10 amps while running. Thats not counting startup current. Im sure herb and suds is right in saying 12 is overkill but safe.
See, this is closer to what I was thinking.
I mentioned it in some other thread, and linked to growmau5 video where he planned his latest growroom (I'll link again if any wants to see) and talks for a min or two about this specifically. And his example lines up with my limited personal experience.
I have a 12kbtu portable, it's 120V, it's not a new 'inverter' style, and it draws just about 12A max (not including inrush/startup, never measured that). So, I duno why a similar, 12kbtu AC unit, running at
240V wouldn't draw *approximately* half that current - i.e.: about 6A.
So, what's said in the video sounds logical to me, almost a guideline of 12A per tonne (12kbtu) at 120V, or 6A per tonne (12kbtu) at 240V. Inversely proportion.
From what I've been able to find video of, these inverter mini split units, even the "mid range"(?) and DIY style units have soft starts, very gradual amperage draw and I didn't see an huge inrush spike at all (and most if not all I saw were 120V though), definitely not a spike larger than the actual max running current draw like plain old compressor style units - correct me if I'm wrong there.
Does this make sense to you lot?
A cust. service guy I called at an ac company earlier said 12awg was "on the cusp" (haha). But I think he said the max running draw was like 12A, maybe - maybe less, he didn't sound 100% and it wasn't too clear.
Thanks guys.