You are running a feed a 20 amp 240 volt feed to air air condition compressor outside. You decide to run a 12-3 RX wire and install a weatherproof GFI receptacle across the red and black wire of that 12- RX wire and use the black and red wire for the HVAC. The receptacle is wired in before the disconnect, so that you can De-energize the AC and still have the recpt. hot.
Does this meet code? Yes? No, if not, code sections please.
It certainly sounds like an interesting idea but I am going to sharpen my pencil and start looking at that condenser label. You might get away with it if you had a small mini split with a 10a or less FLA. (210.23(A)(2) and 440.34)
Sure! Why not? (Though there might be other issues if you put 240 volts across a 120v GFCI :D)
Ultimately, you're describing a sort of tap - though no additional overcurrent protection is needed, as you're within the ratings of the conductors all the way.
Or, are you? Any condenser that calls for a maximum 20 amp breaker is also going to allow the use of #14 wire. You're also going to need a disconnect downstream, in addition to the breaker in the panel
There is 210.63, but it prohibits the required receptacle being connected to the LOAD side of the disconnecting means, this is from the 2008 NEC.
210.63 Heating, Air-Conditioning, and Refrigeration Equipment Outlet. A 125-volt, single-phase, 15- or 20- ampere-rated receptacle outlet shall be installed at an accessible location for the servicing of heating, airconditioning, and refrigeration equipment. The receptacle shall be located on the same level and within 7.5 m (25 ft) of the heating, air-conditioning, and refrigeration equipment. The receptacle outlet shall not be connected to the load side of the equipment disconnecting means. Exception: A receptacle outlet shall not be required at oneand two-family dwellings for the service of evaporative coolers.
Technically it works, but if the AHJ asks if the 2-pole breaker is intended, and UL Listed, to protect a line-to-neutral load you may have a tough time answering. About half of the time that I have seen this type of installation it has been passed, and gigged the other half.
Also 210.23(A)(2) prohibiting receptacles on a circuit feeding 'fixed in place' equipment would come into play.
Besides...if it were that easy why would they sell disconnect switches that have a GFCI already installed in them? Go to www.geindustrial.com and search for DET-382 to see the GE product; several other manufacturers have the same thing.
IMHO I would suggest that you run this question by the AHJ to make sure that you won't have to tear anything out and do it over.