A question about Lightning

[SlipStream77]

There was a brief electrical storm over here on Sunday and the lights dimmed on one or two occasions.

Presumably this is due to a lightning strike, but why do they dim?

[anonymous-user]

Assuming it was due to a lightning strike, the lines are protected by "spark gap" devices. Used to be actually a gap the spark could jump when the voltage got high enough, but often now passive semi-conductor devices. However, once they start conducting, they continue to conduct until the line voltage falls low enough for the device to arrest the current flow, this is lower than the normal line voltage. Hence, for a short period of time, the line voltage is lower than normal.

Added to which, the lightning strike is usually on one of the higher potential lines, sperated from the consumers by one or more transformers. When a single phase is hit, this saturates the transformer and results in lower transmitted power to all the output phases.

[SlipStream77]

That's interesting thanks.

[Watchman]

That's actually quite fascinating. Thanks.

[thinfourth2]

Max_Torque said:

Assuming it was due to a lightning strike, the lines are protected by "spark gap" devices. Used to be actually a gap the spark could jump when the voltage got high enough, but often now passive semi-conductor devices. However, once they start conducting, they continue to conduct until the line voltage falls low enough for the device to arrest the current flow, this is lower than the normal line voltage. Hence, for a short period of time, the line voltage is lower than normal.

Added to which, the lightning strike is usually on one of the higher potential lines, sperated from the consumers by one or more transformers. When a single phase is hit, this saturates the transformer and results in lower transmitted power to all the output phases.

Nah rubbish

We both knows its a guy back at the power station playing with things for dramatic effect

[illmonkey]

thinfourth2 said:

Nah rubbish

We both knows its a guy back at the power station playing with things for dramatic effect

I'd have hoped it was some scum trying to nick the metal getting fried.