I've normally only ever had to consider PME / TNC-S supplies, but what is the common practice for earthing in this scenario in a TNC-S scenario..
If you have a TP&N submain terminating in a barn with local earthrod, and the structural steelwork is bonded with 16mm² cable.
Say you were looking to run an additional submain to an adjacent barn 15m away. What are the options?
1) Rely on the earthing on building A assuming CPC on cable is sufficient, or run a CPC equal to largest phase conductor.
2) Earth The supply end of of the cable, and isolate at remote end and provide local earth here.
3) Add new earth rod in / at new barn bond steelwork and connect this in parallel with the first submain via cable CPC or additional conductor.
4) I've missed something obvious.
If you have a TP&N submain terminating in a barn with local earthrod, and the structural steelwork is bonded with 16mm² cable.
Say you were looking to run an additional submain to an adjacent barn 15m away. What are the options?
1) Rely on the earthing on building A assuming CPC on cable is sufficient, or run a CPC equal to largest phase conductor.
2) Earth The supply end of of the cable, and isolate at remote end and provide local earth here.
3) Add new earth rod in / at new barn bond steelwork and connect this in parallel with the first submain via cable CPC or additional conductor.
4) I've missed something obvious.