Could we use 12/20kv (24kv) cable to replace 3.6/6kv (7.2kv) cable in 3.3kv system voltage?
What is the standard reference?
Theoretically speaking it is possible. However it depends on application - as current carrying capacity, armouring, earthing, bending radius, reduced smoke and other.
Reference: 1.8/3.3 see BS 5467 and for 12/20 IEC 60502-2.
Above is a snippet.