The "thickness" of an IEC cable, particularly when referring to IEC 60228 standard cables, is primarily defined by its conductor cross-sectional area rather than a single overall cable diameter. This cross-sectional area directly determines the cable's current-carrying capacity. The overall physical diameter of an IEC cable can vary significantly based on factors such as insulation thickness, voltage rating, the number of individual cores, and the presence of any outer sheathing or armouring.
For electrical cables, especially those conforming to international standards like IEC 60228, the crucial dimension related to their "thickness" in terms of electrical performance is the conductor's cross-sectional area. This standard specifies the nominal cross-sectional areas for conductors in various types of cables, ensuring consistency and safety across different applications.
Conductor Cross-Sectional Area Sizes (IEC 60228)
According to the provided reference from Eland Cables, which details IEC 60228 standard cables, common conductor cross-sectional area sizes include:
| Conductor Cross-Sectional Area Size |
|---|
| 0.75mm² |
| 1mm² |
| 1.5mm² |
| 2.5mm² |
These values represent the metallic area through which current flows. A larger cross-sectional area allows for the transmission of higher currents with less resistance and heat generation.
Why Cross-Sectional Area is Key
- Current Capacity: The primary reason for specifying conductor cross-sectional area is its direct correlation with the cable's ampacity (maximum safe current). Thicker conductors (larger cross-sectional area) can handle more current.
- Voltage Drop: Larger conductor areas also lead to lower electrical resistance, which minimizes voltage drop over distance, ensuring efficient power delivery.
- Standardization: IEC 60228 standardizes these areas to ensure interchangeability and safety in electrical installations globally.
Overall Cable Dimensions
While the conductor's cross-sectional area defines the electrical "thickness," the overall diameter of an IEC cable will be larger due to additional components like:
- Insulation: The material surrounding each conductor to prevent electrical contact. Its thickness depends on the cable's voltage rating.
- Fillers: Materials used to maintain the cable's circular shape, especially in multi-core cables.
- Inner Sheath: An intermediate layer that can provide mechanical protection or a bedding for armour.
- Armour: For mechanical protection in harsh environments, often made of steel wire or tape.
- Outer Sheath: The outermost protective layer, providing environmental resistance (e.g., against moisture, UV, chemicals).
Therefore, when asking "How thick is IEC cable?", it's most precise to consider the conductor's cross-sectional area as the fundamental measure provided by standards like IEC 60228, while acknowledging that the external diameter is a variable design parameter.
