I am designing a road way lighting cct. 20x250w (urbis)luminaires (each ballast has a max of 3A)@ 230v ac. Is there a standard for underground (via 4" pvc ducts) low voltage cables. (Must be armoured cable) The lamps are spaced 30m apart.
it will depend on the nature of the project, if it is dry area you can use armoured cable direct burried without PVC ducts,and ensure there will be no any future excavation.
As per my knowledge & experience better to use unarmoured cable with PVC duct, for future protection & safety.
