Sorry guys but this is all wrong.
The braid on old type SEU cable is most definitely a neutral conductor. These are 120/240v circuits, NOT simply 240v. The braid is the neutral and the case of the applaince (ground) was allowed to be bonded to the neutral in older codes, thus eliminating the need for a separate ground to be run.
There is no mandate to require these circuits to be upgraded as existing circuits which were legal when installed are still legal.
Thing is it was never legal to run these types of circuits from sub-panels. They were required to originate from the service equipment.
ANY conductor that carries current is either and ungrounded (hot) conductor, or a grounded (neutral) conductor. NEITHER is a ground (grounding condcutor).