An electrical diagram illustrating a 3-phase TN-C-S system from a substation to a hotel, with an EV charging point.

You’re basically being asked to show: - A 3‑phase 400 V TN‑C‑S system from the substation transformer to the hotel. - A local TT arrangement at the EV charging point (with its own earth electrode). - The total earth fault loop path for a fault at the EV charger. Here’s a clean, exam‑style text diagram you can copy/redraw neatly on paper. ```text SUBSTATION / DNO NETWORK ------------------------ 11 kV / 400 V TRANSFORMER (Star-connected LV winding) HV ▲ │ │ ▼ ┌───────────────────────┐ │ 11 kV / 400 V Tx │ │ │ │ LV SIDE (400 V) │ │ 3PH + N │ └───────────────────────┘ │ │ │ │ │ │ │ └───────── N (star point) │ │ └────────────── L3 │ └─────────────────── L2 └──────────────────────── L1 LV EARTHING (PEN CONDUCTOR) --------------------------- ┌───────────────────────┐ │ PEN (combined N+PE) │ └───────────────────────┘ │ │ (TN-C section) │ UNDERGROUND / OVERHEAD LV CABLE -------------------------------- │ ▼ SERVICE HEAD / PME POINT (HOTEL) -------------------------------- TN-C-S ARRANGEMENT ┌───────────────────────────────┐ │ SERVICE HEAD / CUT-OUT │ │ L1 L2 L3 PEN │ └───────────────────────────────┘ │ │ │ │ │ │ │ └──── PEN │ │ └──────── L3 │ └─────────── L2 └────────────── L1 PEN SPLIT INTO N + PE (TN-S INSIDE) ----------------------------------- ┌───────────────┐ │ MAIN EARTH │ │ TERMINAL (MET)│ └───────────────┘ ▲ ▲ │ │ │ └─── PE to HOTEL INSTALLATION └────────── N to HOTEL INSTALLATION HOTEL MAIN DISTRIBUTION (SIMPLIFIED) ------------------------------------- L1 L2 L3 N PE Mehr sehen