What Cable for Electrical Installation? Complete Wiring Guide
Walking into an electrical wholesaler can be overwhelming with the variety of cable types available. Choosing the right cable is crucial for the durability and safety of your installation. What cable should you choose for a single-family home?
Cable sizing should always be checked together with circuit breaker selection. The cable protects the load path, and the breaker protects the cable, so one choice without the other is incomplete.
Basic Cable Designations
In concealed installations, various cable types are used depending on your region. Common types include:
- Solid copper conductors: Best for fixed installations in walls.
- PVC insulated: Standard insulation type for domestic use.
- Flat cables: Easier to install in plaster.
Flexible cables (stranded conductors) are used for extension cords but should never be permanently installed in walls!
What Cable Size Where?
- Lighting: 3-core 1.5mm². Always use 3-core cable (even for single switches) to maintain protective earth continuity.
- Sockets: 3-core 2.5mm². Provides adequate current-carrying capacity for typical household devices.
- Induction hob: 5-core 2.5mm² (for 3-phase installation).
- Heat pump or other large loads: check the dedicated heat pump electrical installation requirements instead of reusing generic socket assumptions.
Wire Colors Matter
Never ignore the colors!
- Green/Yellow: Protective Earth (PE) – ALWAYS and ONLY for protection.
- Blue: Neutral (N).
- Brown/Black/Grey: Live/Phase (L).
Cable selection in a real project workflow
The fastest way to avoid mistakes is to size cables inside a complete online electrical design workflow: define circuits, assign loads, verify breaker choice, and only then finalize materials.
In Electro Planner, you can calculate total cable lengths by type, check them against circuit logic, and make purchasing and cost estimation much simpler.
FAQ
What cable size for socket circuits?
Socket circuits use 2.5mm² copper cable (NYM-J or YDY type) protected by a B16 circuit breaker. This combination supports up to 16A continuous load (3,680W at 230V) per PN-HD 60364-5-52.
What cable size for lighting circuits?
Lighting circuits use 1.5mm² copper cable protected by a B10 circuit breaker, supporting up to 10A (2,300W at 230V). This is sufficient for any modern LED lighting circuit.
What cable size for a heat pump?
A heat pump typically requires 6mm² cable with a B25 or B32 circuit breaker depending on the rated current on the unit's data plate. Always size cable to match the breaker rating.
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