How to Select Cold Shrink Cable Accessories-Managing Electrical Stress of Cable Voltage Rating

How to Select Cold Shrink Cable Accessories-Managing Electrical Stress of Cable Voltage Rating

As for cold shrink cable accessories, widely concerned as one of the key components in electrical infrastructure of contemporary electrical industry, basically including terminations and joints.

By providing sealing, insulation, as well as stress control, cold shrink terminations and joints fictionalized in connection between the equipment termination or another cable connector.

Regarding to heat shrink cable accessories, it requires open flame or hot air tools, howsoever cold shrink therefore deployed pre-expanded materials been fixed to a removable core.

As this core is pulled out, a tight and seamless cable seal therefore would be formed in a quickly shrink, which featured a faster, easier and safer installation.  

It requires a analysis of carefulness to choose the right cold shrink accessories, of the cable system itself. Hereby, this article tend to explore the correct choice upon selection of cable accessories of termination and joints from Managing Electrical Stress of Cable Voltage Rating.

One of the most crucial factors is the voltage level of the system which determines the intensity of the electrical stress that must be controlled by accessory .

At low voltages(LV; e.g., 0.6/1 kV), electrical stress is manageable. In order to prevent water or dust ingress, robust mechanical connections and effective environmental sealing are concentrated on being provided with accessories. In addition, Strain control is usually integrated into the design.

At medium Voltage (MV; e.g., from 6 kV to 35 kV), the more voltage increases, the more intensely concentrated of the electric field at the point where the conductor's screen is terminated. The field will lead to partial discharge and eventual insulation failure if it not properly controlled. Therefore, one geometric stress control component is included in one MV cold shrink termination. The geometric stress control component usually called "stress cone",because of featuring a molded layer of conductive or semi-conductive silicone rubber, it can gradually grades electrical stress and spreads it over a larger area to a safe level. Therefore,the quality and design of this stress control element are paramount.

At High Voltage (HV; e.g., 66 kV and above), electrical stress management is one of the dominant design factors.Accessories are longer to provide a longer leakage current path along the surface to prevent flashover and incorporate stress grading materials. Therefore, The margin for error in installation and selection is minimal.

Selection application: It’s necessary for us to select an accessory whose voltage rating is equal to or greater than the system's operating voltage. Otherwise, using an LV accessory on an MV cable will result in catastrophic failure. In addition, the rating (e.g., 8.7/15 kV) is always clearly marked on the product.