Elect cable in orange PVC in trench?

Good reading

Question is about Elect from house to shed
I dug the trench and laid orange PVC pipe
Sparkie installed the cable and switchboard etc etc
Now I need to backfill the trench

1. Do I need to:
lay a plastic marker strip over the full length of cable in the trench
200mm above the orange PVC pipe.
or is that only for unencased cable?

2. Do I need to:
Put up marker signs where any cable enters or leaves a building.
or is that only for unencased cable?

3 Do I need to:
provide mechanical protection for the cable from the trench depth
to where it enters the edge of the concrete slab
or is that only for unencased cable?

Thanks in anticipation


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