TYPES OF CABLE & ITS RATINGS

 TYPES OF CABLE & ITS RATINGS

Electrical cables are classified based on their voltage rating, current-carrying capacity (ampacity), size, core type, and application. Below is a detailed explanation of different cables used in electrical systems.

1. Voltage Rating of Cables

Cables are categorized based on voltage levels:

1. * Low Voltage (LV) Cables: Up to 1kV, used for household wiring, small industries, and control systems.
2. * Medium Voltage (MV) Cables: 1kV - 33kV, used in distribution networks, industrial plants, and underground power supply.
3. * High Voltage (HV) Cables: 33kV - 220kV, used for power transmission over long distances.
4. * Extra High Voltage (EHV) Cables: 220kV 400kV, used in national grid transmission networks.
5. * Ultra High Voltage (UHV) Cables: Above 400kV, used in high-power bulk transmission systems.

2. Cable Sizes and Their Current-Carrying Capacity

Cable size is measured in square millimeter's (mm²) and determines how much current it can safely carry.

Common sizes include:

1. * 1.5mm² to 6mm²: Used for lighting, socket wiring, and small appliances (ampacity 16A - 40A).
2. * 10mm² to 35mm²: Used for heavy loads such as air conditioners, small motors, and panel feeders (ampacity 60A-125A).
3. * 50mm² to 185mm²: Used for distribution feeders, industrial power supply, and medium voltage networks (ampacity 150A - 400A).
4. * 240mm² to 500mm²: Used in high-voltage substations and transmission lines (ampacity 450A - 700A).

3. Number of Cores in Cables and Their Use

The number of cores in a cable depends on its function:

1. * Single-Core Cables: Used in high-voltage transmission and substations.
2. * Two-Core Cables: Used for single-phase power supply.
3. * Three-Core Cables: Used for three-phase power distribution.
4. * Four-Core Cables: Used for balanced three-phase loads with neutral.
5. * Multi-Core Cables: Used in control circuits, automation, and instrumentation.

4. Types of Cables and Their Applications

Different types of cables are used based on insulation type and protection requirements:

1. * XLPE (Cross-Linked Polyethylene) Cables: Used in underground transmission and high-voltage applications due to their thermal resistance.
2. * PVC (Polyvinyl Chloride) Cables: Used in domestic and commercial wiring due to their flexibility and affordability.
3. * EPR (Ethylene Propylene Rubber) Cables: Used in industrial flexible wiring and harsh environmental conditions.
4. * Armored Cables (SWA/AWA): Used in outdoor installations and underground networks to prevent mechanical damage.
5. * Overhead Conductors (ACSR, AAAC, AAC): Used in power transmission and distribution networks.
6. * Control Cables: Used in industrial automation and control systems for signal transmission.