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Practical 2025-07-25 · 9 min

Apartment electrical design per PUE: complete walkthrough

Step-by-step walkthrough of a real 60 m² apartment electrical project: plan, load calculation, breaker selection, panel layout, and BOM.

Author: GorkyCAD Team

Initial data

Let's walk through a real project: a 60 m² two-room apartment in a panel building. Client — a family of three. Full electrical supply design per PUE/IEC standards required.

Step 1: Floor plan and electrical point placement

In GorkyCAD, we load the floor plan (DWG/DXF or draw with built-in tools) and place:

- Kitchen (12 m²): 6 outlets (work zone — 4 doubles above counter + 1 fridge + 1 stove), 2 lights, 1 switch

  • Living room (18 m²): 5 outlets (TV zone — 3, general — 2), chandelier + wall lamp, 2 switches (main + pass-through)
  • Bedroom (14 m²): 4 outlets (both bedside + workstation + general), chandelier, 2 switches
  • Bathroom (4 m²): 1 outlet for washing machine, light, switch (external)
  • Hallway (8 m²): 2 outlets, light, switch
  • Balcony (4 m²): 1 outlet, light

    Total: 19 outlets, 7 light points, 8 switches.

    Step 2: Grouping and load calculation

    Distribution into groups per IEC 60364:

    | Group | Rooms | Load | Icalc |

|---|---|---|---| | Gr.1 — Lighting | All rooms | 0.8 kW | 3.5 A | | Gr.2 — Kitchen outlets | Kitchen | 3.5 kW | 15.2 A | | Gr.3 — Room outlets | Living, bedroom, hallway | 2.0 kW | 8.7 A | | Gr.4 — Washing machine | Bathroom | 2.2 kW | 9.6 A | | Gr.5 — Balcony | Balcony | 0.5 kW | 2.2 A |

Total installed: 9.0 kW. Calculated (diversity factor 0.7): 6.3 kW. Input current: 28.7 A.

Step 3: Breaker and RCD selection

Group breakers:

- Gr.1: C10, cable VVGng-LS 3×1.5

  • Gr.2: C20, cable VVGng-LS 3×2.5
  • Gr.3: C16, cable VVGng-LS 3×2.5
  • Gr.4: C16, cable VVGng-LS 3×2.5
  • Gr.5: C10, cable VVGng-LS 3×1.5

    RCDs:

    - RCD1 (Gr.2 — kitchen): 25A, 30 mA, Type A

  • RCD2 (Gr.3-4 — rooms + washer): 25A, 30 mA, Type A
  • Gr.1 and Gr.5 without RCD (lighting — not required)

    Main breaker: C40, input cable 3×6 mm².

    Step 4: Panel layout

    Surface-mount panel, 24 modules. Fill order (top to bottom):

    1. Main C40 — 2 modules

2. RCD1 25A/30mA Type A — 2 modules
  • 3. Gr.2 (C20) + Gr.3 (C16) + Gr.4 (C16) — 3 modules
  • 4. RCD2 25A/30mA Type A — 2 modules
  • 5. Gr.1 (C10) + Gr.5 (C10) — 2 modules
  • 6. Neutral bar + ground bar — 4 modules

    Total: 15 modules used. Reserve: 9 modules.

    Step 5: BOM

    GorkyCAD generates the BOM automatically — panel, MCBs, RCDs, cables, outlets, switches, lights — all counted from the model.

    Step 6: Cable schedule and export

    GorkyCAD generates a cable schedule with routing and lengths. Export: PDF (full album), Excel (BOM), JSON (for integration).

    Result: project ready in 25-30 minutes. All calculations, selectivity and voltage drop checks — automatic.