210.63(a) its allowed

[new-master]

I was studying tonight, I came across a question regarding the service receptacle for the HVAC unit.
But also read this part and 210.63(a).
I was wondering if in case I forgot to run a dedicated circuit or a 120v circuit to the roof. Is it allow to tap from one leg of the 240v line side of the HVAC circuit like a commercial scenario for example.
Where we have to a lot of work just to get a 120 power outside again.

 

[LarryFine]

I was wondering if in case I forgot to run a dedicated circuit or a 120v circuit to the roof. Is it allow to tap from one leg of the 240v line side of the HVAC circuit like a commercial scenario for example.

If you can use the circuit as a feeder to a sub-panel with separate A/C and receptacle breakers, and you have an uninsulated grounded conductor, or use a 240-120v transformer, yes.