The Critical Role of Shielding Layers in X-Ray High-Voltage Cables

Shielding layers are the unsung heroes of high-voltage cables for X-ray machines, directly ensuring operational safety and avoiding insulation failures. Their design targets a key risk: partial discharge caused by gaps or uneven electric fields. Here’s a breakdown of their core functions:

X-ray cable conductors are typically twisted wires, which easily form air gaps with the insulating layer and have uneven surfaces—both leading to electric field concentration. To solve this, a semiconductor shielding layer is applied to the conductor surface. This layer is equipotential with the conductor and maintains tight contact with the insulation, effectively eliminating partial discharge between the conductor and insulation.

Gaps can also form between the insulation surface and the cable sheath, another trigger for partial discharge. A second semiconductor shielding layer is therefore added to the insulation surface. It bonds closely with the insulation and is equipotential with the metal shielding layer or sheath, preventing partial discharge between the insulation and sheath.

For extruded insulated cables without a metal sheath, a metal shielding layer (wrapped in copper tape or copper wire) is mandatory alongside the semiconductor layers. Its roles are threefold: carrying capacitive current during normal operation; acting as a channel for short-circuit current if a system fault occurs; and enhancing overall electric field shielding.

When purchasing high-voltage cables for X-ray machines, always verify the integrity and quality of these shielding layers to ensure safe, reliable operation. Weifang NEWHEEK supplies certified high-voltage cables with compliant shielding structures. For inquiries, contact us: +86 19953639012.