Here in Oregon, when conductors are brought from the top of the pole to an underground cable at the bottom of the pole, the PVC enclosure of the conductors is mounted on standoffs of what looks like 4 - 8 inches so that the PVC (or whatever material is used) is not actually touching the pole except for the supports. I have seen this done for high voltage distribution (34.6 kV) but also for household service entrances (240/120 V) voltage levels.
I'm curious to know why the standoff from the pole, I haven't seen this in other states. Anybody know for sure?
It seems obvious that this is to protect the wooden pole some way, but from what? Because of the cooler climate, Oregon has comparitively less lighting than most other states. Many transmission circuits are run without grounded static wires because of this. Does the standoff make it easier to replace a damaged pole? Is it somehow a safer installation?