250.4(B) talks about grounding equipment on ungrounded systems. Although it does not specifically reference 250.122 it is implied as a good guideline with these words
250.4(2) Bonding of Electrical Equipment. Non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the supply system grounded equipment in a manner that creates a low-impedance path for ground-fault current that is capable of carrying the maximum fault current likely to be imposed on it.
