A lightning arrester is a device, essentially an air gap between an electric wire and ground, used on electric power transmission and telecommunication systems to protect the insulation and conductors of the system from the damaging effects of lightning. The typical lightning arrester has a high-voltage terminal and a ground terminal. When a lightning surge travels along the power line to the arrester, the current from the surge is diverted through the arrester, in most cases to earth.
Powerline worker performs maintenance of a lightning arrester on an electrical transmission tower in New Brunswick, Canada
Base of a mast radiator with spark gap and series inductance in form of a coil with one winding in the feeder line
The antenna is attached to A, and a pipe in the ground is attached to E. The television signal can go from A to B but not from B to C or from C to D. However, when the high voltage of lightning hits, it can easily go through the air from B to C and from C to D and E.
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals.
Ceramic insulator used on an electrified railway
Three-core copper wire power cable, each core with an individual colour-coded insulating sheath, all contained within an outer protective sheath
PVC-sheathed mineral-insulated copper-clad cable with two conducting cores
Pin-type glass insulator for long-distance open-wire transmission for telephone communication, manufactured for AT&T in the period from c. 1890 to WW-I; It is secured to its support structure with a screw-like metal or wood pin matching the threading in the hollow internal space. The transmission wire is tied into the groove around the insulator just below the dome.
