Stress cones are a means of preventing insulation failure at the termination of a shielded cable caused by the high concentration of flux and the high potential gradient that would otherwise exist between the shield termination and the cable conductor
A stress relief cone is made by increasing the separation between the shield termination and the conductor cable. Precautions must be taken to insure a termination which is free of dirt and foreign matter and insulating compounds and tapes must be applied in a prescribed manner. Potheads may also be used with the stress relief cone termination.
Typical uses for stress cones would be in pad-mounted transformers, switchgear, high-voltage motor installations or in most applications were shielded cable is being terminated.
Normally Stress Cones are not provided by the motor manufacturer but are made by the motor installer. When a customer requires stress cones, the manufacturer will supply a conduit box with sufficient room for the stress cone on each lead.