Now that's what you call a circuit breaker...

Heisenberg · Mar 5, 2012

A picture speaks a thousand words, well in this case a video...

500,000 volt line opened under load - YouTube

No doubt E54 will be able to explain what is actually happening, I find the description of the clip difficult to understand :yes:

RWJ · Mar 5, 2012

Heisenberg said:
A picture speaks a thousand words, well in this case a video...

500,000 volt line opened under load - YouTube

No doubt E54 will be able to explain what is actually happening, I find the description of the clip difficult to understand :yes:

I love HV you tube videos!! :heart:

malcolmsanford · Mar 5, 2012

RWJ said:
I love HV you tube videos!! :heart:

You really have to get out more .......................

Engineer54 · Mar 5, 2012

Well my guess is, that what your looking at, is the extension of the breaking ark continuing probably due to a highly humid atmosphere. The size of the contact gaps usually dissipate such breaking arks during the opening travel, but when high humidity is present, until the heavy ionisation has been used up by the ark this is what you see...

If you look at some of the other video's on (You Tube) breaking high voltages, you'll see similar effects on switch opening sequences. There is usually a greater risk of these parking displays when the switch(es) are opened under load....

I don't, and have never worked on such high voltages. Most of my experience is on MV, in the 11KV to 33KV although i have also been involved in a small way on 2No of 66 KV sub stations. Each voltage band has it's own unique characteristics, and what your talking about is what would be called, Super High Voltage in the UK. As far as i know UK has only upto 400KV networks, whereas the States (because of the distances involved) have 500/750KV up to 1 Million volt transmission networks....

Knobhead · Mar 5, 2012

The two tubes to the right of the picture are double break SF6 “puffer” switches, these failed. The load was broken instead by the “off load” isolators, which they aren’t designed to do. Hence the arc.

The sequence should be
1/ the puffer beakers open simultaneously controlling the arc
2/ the off load isolators open

It was a set up, the power company knew the puffer breakers had failed (low gas alarm) and so sent out the film crew to catch the results.

sparkiegaz · Mar 5, 2012

mmm not wanting to wave a metal pole around near that,,,i was at sizewell back before xmas and they were switching the breaker on feeding 24kv into the 400kv transformer,,,made us all cabin up on the night shift just incase it went bang,,,apparently one at hinkley blew up and chucked metal everyware ,,,