Electric baseboard: 80% rated circuit load, and wire ampacity

[Theodore]

Hi,
I'm wiring four new electric baseboards in my basement.
All four are 220Volt units: 500W, 500W, 1000W, 1500W, for a total of 3500W. The longest run is less than 100ft.
If I understood the NEC, putting all of this on one circuit will require a 20Amp breaker (1.25*3500W/220V), and the wire can be #12AWG.
Did I get that right, and am I missing any other design factor?

Many thanks
Theodore

 

[Theodore]

Hi.
Just to close this out, I got one very knowledgeable response with references to NEC, on Google Groups (along with typical unmoderated chatter).
In case anyone wants to read it:
https://groups.google.com/forum/#!topic/alt.home.repair/w9D3G5UMVhE