In the original installation they were oil filled for both cooling and electrical insulation.

The mineral mica was commonly used at that time for electrical insulation.

Valentine read the pictograms on the poles, saw the electrical insulation.

They often treat exposed power cables as tree branches, and gnaw on the electrical insulation.

They can be used for electrical insulation due to their dielectric properties.

However the Navy replied that the electrical insulation had been improperly installed during construction.

When the mattresses caught on fire, the wood ties under the train and electrical insulation were ignited.

This myelin is found in almost all long nerve fibers, and acts as an electrical insulation.

He smelled stale food and something that reminded him of burned-out electrical insulation.

Also, the spark-plug wires eventually wear out and lose some of their electrical insulation.