I am installing some outdoor lighting. There will only be one 120 VAC circuit feeding all the AC devices, pumps and lights. There will be some low voltage lighting in the same ditch but buried at a different depth. While digging I found three conduits feeding an outbuilding from the main residence. These PVC conduits are barely 6 inches deep and definitely have 240 VAC circuits in them. I thought PVC had to be 18 inches and 120 VAC UF cable was 12. 30 volts and lower were 6 inches.
Is there any rule on the number of UF cables in a trench?
Thanks for any replies.