Cable Trench with 2 Voltage Levels (800Vac and 34.5kVac)

[johnnyquest]

Hello,

We have a project where there are sections where 34.5kVac cables will be laid below 800Vac cables. Conductors are Aluminum.

Any chance anyone knows a standard which states the min. allowable separation distance when cables of different operating voltage levels are laid in the same trench?

Thanks in advance!