HT and FO Cable Crossing

You need to determine which codes and standards apply to your jurisdiction, then follow those rules. If the two cables are utility owned and maintained in the U.S. the clearances would be per the National Electrical Safety Code, and if not utility owned, per the National Electrical Code ... more or less.

For either code to be in effect, that code has to have been adopted by the local jurisdiction. In most states, the public utility commission, or state legislature adopts the National Electrical Safety Code, but they may lag by a few years, so the most recent many not be the applicable version. In most states, state legislature or local building departments adopt the National Electrical Code as the rule, but again they may lag by a year or two, and they may have additional rules of their own.

If you are not in the United States, I do not have a clue.

Ramadass.ar:

Look also at what the FO cable's strength member is. It is most likely "kevlar", but if it is metal, then you have other significant issues with regard to separation.

--JMM