What do you all use as branch circuit wiring to a hot tub. I need to run a circuit through a crawl space from main panel to spa gfci panel. I would love to use 6/3 NM, however I must maintain a full size #6 ground. Is there a cable that has a full size ground wire?
If this is a dwelling, I am not sure why you can't use RX.
Any wiring method employed shall contain an insulated copper equipment grounding conductor sized in accordance with 250.122 but not smaller than 12 AWG.
and (4) says
One-Family Dwellings. In the interior of dwelling units, or in the interior of accessory buildings associated with a dwelling unit, any of the wiring methods recognized in Chapter 3 of this Code that comply with the provisions of this section shall be permitted. Where run in a cable assembly, the equipment grounding conductor shall be permitted to be uninsulated, but it shall be enclosed within the outer sheath of the cable assembly.
Once you get to the exterior wall you will have to transition to another wiring method, RNC and THWN or whatever.
I am not sure I know that one. Is it a local amendment? 680.42 says
A spa or hot tub installed outdoors shall comply with the provisions of Parts I and II of this article
Interior Wiring to Outdoor Installations. In the interior of a one-family dwelling or in the interior of another building or structure associated with a one-family dwelling, any of the wiring methods recognized in Chapter 3 of this Code that contain a copper equipment grounding conductor that is insulated or enclosed within the outer sheath of the wiring method and not smaller than 12 AWG shall be permitted to be used for the connection to motor, heating, and control loads that are part of a self-contained spa or hot tub or a packaged spa or hot tub equipment assembly. Wiring to an underwater luminaire shall comply with 680.23 or 680.33
Some of the Hot Tub instructions call for the full size ground that your talking about. It is not a NEC requirement...well for the full size ground, but you have to follow instructions according to 110.3(B)
I don't know of a cable that has a full size ground that you are looking for except on special order, so it is difficult to comply.