can #6/2 NM wire (White,Black, bare wire ground be used for spa ?
 

:huh:Question: My home was built in 1996. Has dedicated circuit of 240 volt with NM wire (1 hot-black, one neutral-white, and a bare ground. All three wires are same guage (#6). I have been told that this set up can be used by installing a 2 pole 50 amp gfci in my 200 amp box and using the white neutral as a hot lead and using bare wire as ground, assuming all equipment is 240 volt. There are companys which sell spa packs to order with 3 wire hook up. Is this idea safe?legal? or am I going to have to go to a 4 wire set up? Any feed back from knowledgable electricians will be greatly appreciated. Thanks, T.T.p.s. Heater will be a 5.5kw

IF you mark or label that white conductor to another color, such as black, red, or blue, AND there is no neutral required for the tub, then it should be sufficient.

It depends on the spa.
This is not an "older" circuit. It is simply a straight 240v circuit.