SoCa Edison has "contractors" installing the ducts around here too. It doesn't matter if they're electricians or not. The same goes for transformer pads, hand holes, etc.
A SCE inspector will inspect the open trench, slurry when required, mandrel test the ducts, and give the approval for backfill.
The first time SCE has any "electricians" on the job is when they set transformers and pull the conductors into the ducts.
