4160 and 34.5kV in the same manhole

Status
Not open for further replies.

mshields

Senior Member
Location
Boston, MA
Is it permissible to have these two voltages in the same manhole.

I know that under 600V, the rule is that the insulation needs to be the same. What about when we get up MV and HV?
 
It is not prohibited unless the cables are unshielded, which is unlikely. See Section 300.3(C), especially the last sentence. Also be aware of requirements in Article 110, Part V starting at Section 110.70.
 
Careful on the belief that for 600V the insulation has to be rated the same, I believe you can still accomplish this in a MH by proper separation.
I personally like separate MH's for LV and I&C, versus MV in it's own. But it adds cost, and there are many installs were it is combined.
 
Unless the manhole is provided with a stacked cable trays [according to IEEE 525 or 422]one feet distance :.
"Trays for cables of different voltage levels should be stacked in descending order with the higher voltage. Instrumentation trays should always be at the bottom. At least 12 inches of clear space should be provided between tray levels."
 
Status
Not open for further replies.
Top