Classic 275,000 volt, 15,000Mva JW420 bulk oil breaker

[DPG]

What is incredible is that someone who I do not know managed to film this very breaker a few days before it was taken out of service. This breaker is bus-coupler WV10 as can be seen in the film on the centre phase oil tank, the WV10 can also be seen on the above Mechbox on the side of my breaker. Item at 4.20 in the clip is the tinpot nasty SF6 breaker that has now replaced it, I wonder how years this is going to last!! At about 6.30 in the clip the yodel alarm sounds before the breaker operates. The last thing I would want to do is to be anywhere near one of these when switching as a few have now blown up with the associated ceramic shrapnel followed by oil explosion/fire!, even when stood the other side of the compound fence.

I think this is the only film on youtube to show a bulk oil 275kv breaker in operation which is bonkers.

He could do with some image stabilisation - that was like an electrical engineer's version of the Blair Witch Project!

 

[Julie.]

From memory, (which isn't very good) I think this interrupts via shuntarc with four-break multi cross-jet expulsion pots.

Mechanism is pneumatic of course.

Probably the most spectacular testing failure I ever witnessed was using shuntarc - and part of it was my design (but not my failure).

They are replacing all these breakers as their design life has been well exceeded, and of course the partial discharge issues with the bushings, so a 10m+ exclusion zone whilst live!

 

[Aaron b]

There's a museum of power in Maldon Essex, Essex and Suffolk Water own. Not been in there myself but was involved in connecting a sub main from there to a pump station nearby. I doubt it compares to what you are trying to achieve. There's some great engineering about that people don't get to see.

 

[pc1966]

I think this is the only film on youtube to show a bulk oil 275kv breaker in operation which is bonkers.

It looks like that substation has an electric fence inside the metal palisade railings?

Effective I'm sure, and strangely appropriate...

 

[jay sean]

It looks like that substation has an electric fence inside the metal palisade railings?

Effective I'm sure, and strangely appropriate...

Most National Grid sub stations are protected by electric fences, but Ive been to some where you still get visitors who want to and will steal copper!!!

 

[UKMeterman]

Most National Grid sub stations are protected by electric fences, but Ive been to some where you still get visitors who want to and will steal copper!!!

I did hear of a case, I think it may have been in the USA, where someone stole parts of the earthing grid, then moved on to the control circuits, which triggered the fault thrower. The fault thrower then caused a voltage differernce across site bridged by thoses who stole the earth mat....

 

[R-fur]

The National Museum of Scotland in Edinburgh has a some switchgear from the origional Grid.