Concentric cable is a type of electrical cable that consists of multiple layers of conductors arranged in a concentric manner. These layers are designed to provide various benefits such as enhanced electrical performance, mechanical protection, and insulation. Concentric cables are commonly used in power distribution, communication systems, and other applications where reliable transmission of signals or electricity is essential.
The structure of a concentric cable typically includes the following components:
- Core Conductor: The innermost layer of the cable consists of a central conductor, usually made of copper or aluminium. This conductor carries the electrical current or signal through the cable.
- Insulation Layer: Surrounding the core conductor, there is an insulating layer made of materials such as PVC (polyvinyl chloride), XLPE (cross-linked polyethylene), or other insulating materials. This layer prevents the current from escaping the conductor and helps maintain the integrity of the signal or electricity being transmitted.
- Metallic Shield: The metallic shield is a layer of wires or tapes that is placed around the insulation. This shield serves multiple purposes: it provides electrical shielding to protect the core conductor from external interference and also helps contain any leakage of electric fields that could affect nearby equipment or cables.
- Insulating Layer (again): Following the metallic shield, there may be an additional insulating layer. This layer offers additional protection and insulation to the cable.
- Concentric Neutral Conductor: This is one of the distinguishing features of a concentric cable. The concentric neutral conductor is a layer of wire helically wound around the insulation layer(s) and serves as both a neutral conductor for the cable’s power transmission and as a protective layer. This neutral conductor can help with fault current distribution and overall cable stability.
- Outer Sheath: The final layer of the concentric cable is the outer sheath, which is typically made from PVC, PE (polyethylene), or other suitable materials. The outer sheath provides mechanical protection to the cable, shielding it from environmental factors such as moisture, chemicals, and physical damage.