Lightning Arresters

Lightning Arresters

A device on an electric power or telecommunication system which diverts power to ground when the system takes sees an extreme voltage spike. 

These devices are designed to work with a direct lightning strike, or an extreme surge from an fault somewhere down the line. 

The lightning arrester is essentially an automatic switch designed to work instantaneously.

Many lightning arresters are needed at each substation as each transformer and piece of switching equipment needs to be protected. 

There are many kinds of lightning arresters, such as expulsion and valve types. 

Note that large circuit breakers at the substation and lightning arresters look similar, they are both tall ceramic tubes.

Lightning arresters built onto a large substation transformer. 

Transformers contain coils of wire with thin polymer insulation on each wire. 

It doesn't take much overvoltage to burn through this insulated wire. 

Large transformers are extremely expensive to replace and repair. 

We use voltage regulators and fault protection to precisely control what voltage goes into the transformer.

Station and line-type arresters can be built into units. 

Units can be stacked in series to create an arrester with a higher rating.