Electrical ageing of silicone oil

In view of its widespread use in cable terminations, new results pertaining to electrical aging (i.e. exposure to repeated electrical discharge events) of silicone oil are reported. A new piece of equipment allowed the discharge characteristics to be controlled and the resulting blackening was correlated to the change in dielectric properties. End of life conditions were determined and the feasibility of a simple optical probe was explored. This could give the operator warning of when the oil is excessively aged, allowing remedial action to be taken.