Insulating Tape Used For 115kV

[livewire9]

The company I work for has a client on the West Coast with a phase-to-ground clearance violation. On a 115kV deadend structure, the inside phase of rigid auxiliary bus just slightly violates the 42" phase-to-ground clearance requirement to a switch vertical operating rod. This was just recently noticed and has been in service for a number of years now. I am proposing to wrap the vertical pipe with insulating tape in the proximity of the rigid bus as opposed to moving the bus over. Has anyone used insulating tape for a similar purpose at 115kV?

 

[thermionic1]

I've only ever seen clearance issues resolved by obtaining the clearance. This is generally accomplished by raising / lowering parts or supporting members.

Maybe Raychem has a solution?

 

[cranky108]

Likely it is grandfathered in to the codes. So as long as you are not changing anything you should be able to keep it.

That said, fixing the problem is the best way.

I know we have used tape on lower voltages because of bird, and rodent problems, but not at 115Kv that I recall.

 

[jghrist]

The minimum phase-ground clearances are based on maintaining a strike distance for the design BIL. See IEEE Sstd 1427, IEEE Guide for Recommended Electrical Clearances and Insulation Levels in Air-Insulated Electrical Power Substations. I don't think that tape would increase the BIL. With no current, the outside of the tape will be at essentially ground potential. It might make it worse by reducing the clearance by the thickness of the tape.

 

[livewire9]

Thanks for the responses. I've worked in the industry for quite a while now. But as you can see I am a structural guy. I thought the insulating tape may discourage an arc from forming between the bus and vertical pipe because of the dielectric layering placed around the switch pipe. Is there any truth to this?