FAQ

A longitudinally water blocking cable is designed with a barrier to prevent the spread of moisture along its length. Longitudinal water blocking stops water from migrating along the cable's core, typically between the conductor strands, insulation layers, or metallic screens. Lateral water blocking ensures that water cannot penetrate the cable in the event that the sheathing is pierced or damaged. Radial water blocking prevents water from penetrating the cable's outer sheath or insulation layers, thereby stopping it from entering the cable structure entirely. Longitudinal water blocking can be achieved through various methods, including the application of water-blocking tapes and powders. These are frequently located on either side of a metallic screen and conductor. Lateral water blocking is typically accomplished by applying a layer of aluminum/polyester tape to the underside of the outer sheath.

Medium and high voltage power cables, typically those in circuits exceeding 2kV, usually feature a shield layer made of copper or aluminum tape. Similar to their use in low voltage cables, metallic wires and tapes are employed to prevent electromagnetic interference. These shields effectively neutralize or significantly diminish the field currents surrounding the conductor or core. The capacitive and inductive charging currents induced under normal operating conditions are subsequently grounded by the metallic screen.

EPR is widely used as an insulation material for electric cables due to its high dielectric strength, and it also serves as a sheathing material with excellent ozone and weathering resistance. EPR has a wide thermal range, typically spanning from -55°C to 150°C. Unlike other organic rubbers, there is no need to tin the copper conductor to prevent deterioration of the rubber.

Water-blocking cables are essential for ensuring reliable operation in environments with high levels of moisture or frequent water contact. These cables employ water-blocking techniques to effectively prevent water ingress, protecting them from damage and prolonging their lifespan.