Schedule 80 is commonly used here for running underground feeders from a pole mounted transformer. Lots of the cities that were originally built with service drops from poles are now requiring all new construction to run their new service feeders underground from these same poles (except in completely new communities, where the service network is already planned as an underground installation). I'm assuming this is in the interest of beautification.
Our job is to trench to the pole (from our new service) and install the PVC run up to the pole (with just enough SCH 80 popping out of the ground for them to couple to). The PoCo then installs the ladder jacks on the pole and the SCH 80 for the first 10 feet or so, then usually (but not always) SCH 40 the rest of the way up to the transformer.
Although this PVC may seem like a bad idea on paper, I've actually seen very, very few problems as a result of this type of installation. In an area with freezing temperatures, however, I could not venture a guess as to the durability of the PVC. I've seen impact from cars, and usually the pole takes most of the beating, where as the PVC will usually either dent or just crack. I've yet to see it break away and leave the feeders exposed.
Personally, I have no problem with it at all. If the PoCo wants it, then the PoCo gets it, and we have little choice in the matter.
