I were thinking like, about power cuts

[harry]

There are numerous circumstances in which they shut down for safety reasons.

[harry]

Much of the switch gear at primary substations id remotely controlled so the load can be reconnected progressively from a central point.

Much of our HV is on ring mains. The protection on the ring identifies the direction the fault current flows and so is able to isolate a small part of the ring. It's therefore quite unusual for a very large area to shut down on fault

[The Natural Philosopher]

that is true, but isolators cant be used to make and break..you have to down the whole ring to isolate a segment and down it again before reconnecting it.

[Nightjar]

We still make around 10 million tonnes of steel each year, compared to just under 18 million in 1990. In the UK, about 2.5 million tonnes p.a. are produced in electric arc furnaces.

Colin Bignell

[Dave Liquorice]

Round here the 11 kV distribution is single lines fed from one end but with normally open air switches so they can feed from the other end if needs be. They don't interupt the supply again after a fault has been rectified, so they must use the isolator switches to reconnect that section. Restoration of normality just means opening/closing NO/NC air switches in the right order so that when a switch is operated it has supply both sides, ie any open NC switches are closed before any closed NO ones are opened.

[Scion]

Bill Wright put finger to keyboard:

Wow, she only passed away a few hours ago.

[John Williamson]

I suspect The Other Mike was referring to the standard of the infrastructure in India, rather than inferring that we don't make steel here any longer.

[Nightjar]

It is surprising how many people seem to think that we no longer have a steel industry.

Colin Bignell

[Andrew Gabriel]

One of which is particularly amusing... The grid-tie spec has a tighter 50Hz requirement than the grid itself. So when the frequency drops badly due to excessive load versus supply, and you could really do with whatever scraps of additional power you can get hold of, all the home microgeneration devices drop off the grid.

The Whispergen gas boiler did have an option for operating as a standalone generator, for which there was an extra 12V SLA battery and controller you added on. This was aimed at things like houseboats. Don't know if the extra controller actually became available before Whispergen was abandoned though.

[Tim Streater]

Or indeed any manufacturing at all. Perhaps they think RR is a Chinese company.

[dennis]

Its not too difficult to create an island when you need one. It would be advisable to pull the main isolator first.

[dennis]

Its the same with manufacturing, we make lots still, we just don't employ as many people to do it.

Don't we make more cars now than we did in the last 50 years?

What has dies is some of the high tech industries which were killed off by BLiar.

[The Other Mike]

Originally called LL

[The Other Mike]

Roll back to the mid 70's and you had not far off 2 million tonnes pa from one site in Rotherham.

Steel production by mass is at a post WW2 low in the UK. What little steel production remains in the UK is almost all high added value product. The impact on the UK grid of these operations is minimal as around the long established steel production areas of the UK the electricity infrastructure was sized for

1960's and 1970's levels of mass production and process efficiency.

[harry]

There is a difference between isolators and switches. A lot of HV switchgear incorporates both.

[harry]

Mine has never gone off for the reason of frequency. It has gone off by reason of over voltage. This was determined to be because the local transformer had the wrong tapping setting and was too small.

[harry]

I can see that went right over your head.

[harry]

Bit like any electrical equipment in fact.

[Tony Bryer]

Steel production in Australia is on the wane even though we're a country built on iron ore and coal. China as ever:

[harry]

Interesting article. But he missed the elephant in the room. China is a "Victorian" society with lots of cheap (near slave) labour. The moment the workforce gets to be wealthy, the industry is no longer competitive.