English Electric Mains shut down/start up procedure

[Lucien Nunes]

People have been known to start opening them, halfway through closing them because they hear arcing.

To use a flight analogy, it's like trying to abort a takeoff after V1, which you only do if the aircraft is incapable of flight. It is better to continue, even if you suspect there is a problem, than to create a worse one by aborting. In an aircraft that would be a runway excursion, with switchgear it's the aforementioned fireball.

Operating open front switchgear on 250-500V DC at lower currents, you can get a clear idea of how an arc behaves according to what you do with the switch handle, without the risk of the severe arc-flash injury that comes with failed MV or HV or even high current LV switching events. IMO every electrical apprentice should get to see and feel this.

 

[Julie.]

What are those disc things all around the room. In fact, what is that room? @Julie. And, errr, I have made a solemn promise to myself to not operate an air circuit breaker anytime soon!
P.S. And why must the OB3 NOT BE OPERATED? Is/was it defective like the above? All very interesting by the way.

The red Yellow and blue busbars are the three phases we connected the equipment to, we could choose the voltage on those from 200V to 38kV depending upon the test requirements, the disks are insulators.

That is a test bay at a switchgear testing station, low - medium voltage, unfortunately I don't have photos of the other bays some of which go to high voltage (66kV+)

The OB3 operates like many of the era and is known as "dependant manual"

This means the speed of contact closure is completely dependent upon the operator, if you are hesitant and do it slowly or even stop and reverse, then the contacts will not make properly.

Switchgear is generally designed to close onto a fault, but opening a fault is not always required (switches), and when it is able to interrupt a fault (breaker), they sometimes use different contacts, and in any case they always need to follow the proper cycle from: contact made, contact separation, arc, arc control, then arc extinction then fully open.

Dependant manual interrupts this cycle.

As long as you make a swift closure, even on to a fault, the breaking cycle can complete safely.

As you may guess I worked at both a switchgear manufacturer and testing station , unfortunately I had to go out and investigate some incidents including a number where deaths had been involved.

I did attend one where an operator had started to close a switch (~11kV) designed in the late '40s manufactured in the 50s - so dependant manual, and realised he hadn't removed the earth links, so hesitated half way through and tried to open it.

5 out of the 6 people in the switchroom died, the one who lived was near the door managed to get out but was engulfed in the burning oil, it was horrific to be honest, one of the worst I investigated.

 

[DPG]

The red Yellow and blue busbars are the three phases we connected the equipment to, we could choose the voltage on those from 200V to 38kV depending upon the test requirements, the disks are insulators.

That is a test bay at a switchgear testing station, low - medium voltage, unfortunately I don't have photos of the other bays some of which go to high voltage (66kV+)

The OB3 operates like many of the era and is known as "dependant manual"

This means the speed of contact closure is completely dependent upon the operator, if you are hesitant and do it slowly or even stop and reverse, then the contacts will not make properly.

Switchgear is generally designed to close onto a fault, but opening a fault is not always required (switches), and when it is able to interrupt a fault (breaker), they sometimes use different contacts, and in any case they always need to follow the proper cycle from: contact made, contact separation, arc, arc control, then arc extinction then fully open.

Dependant manual interrupts this cycle.

As long as you make a swift closure, even on to a fault, the breaking cycle can complete safely.

As you may guess I worked at both a switchgear manufacturer and testing station , unfortunately I had to go out and investigate some incidents including a number where deaths had been involved.

I did attend one where an operator had started to close a switch (~11kV) designed in the late '40s manufactured in the 50s - so dependant manual, and realised he hadn't removed the earth links, so hesitated half way through and tried to open it.

5 out of the 6 people in the switchroom died, the one who lived was near the door managed to get out but was engulfed in the burning oil, it was horrific to be honest, one of the worst I investigated.

That's really scary that.

 

[Julie.]

You've broken that.

Yup.

And I did it deliberately!

 

[timhoward]

A YouTube search for “breaker failure” shows a tragic case of someone presumably winding out a switch under load. (Upsetting video - they don’t survive the massive explosion)

 

[DPG]

A YouTube search for “breaker failure” shows a tragic case of someone presumably winding out a switch under load. (Upsetting video - they don’t survive the massive explosion)

There are a few nasty ones on YouTube.

 

[pc1966]

There are a few nasty ones on YouTube.

Indeed, unlike most mainstream TV there is no checking or public-decency style policies on the depiction of real death and injury.

 

[Vortigern]

Wow @Julie. never realised what sort or work you did. Way past my pay grade and sounds absolutely fascinating. Plus your worked maths on 3P obviously way up there. Good for you. Nice to see a woman in such a place.

 

[Julie.]

Wow @Julie. never realised what sort or work you did. Way past my pay grade and sounds absolutely fascinating. Plus your worked maths on 3P obviously way up there. Good for you. Nice to see a woman in such a place.

Long career!

First job was at a motor rewind company, they said I would need to do a few office duties, but would go down the engineering route, it was a lie. I was just a receptionist

I managed to start as an apprentice for a switchgear company, they partnered with a couple of utilities and a large electrical installation company. After doing the rounds of all departments internally and external, from inspection through the foundry and site stuff like lv installation, and the rounds of a couple of utilities like their apprentices; I went to University, and moved into the testing arena, then the design department - I ended up being quite senior.

I presented quite a few papers on some specialist research, as at one time I was split between working at the factories in Stafford, and Manchester; the Electrical Research Association in Chester, and doing a further degree at UMIST all associated with modelling electrical field theory and its effects - one area was the use of protective suits whilst operating switchgear - it isn't just flameproof, they have electrical characteristics as well.

Just a few lines for so many years!

After that I moved to a college as a lecturer, which I hated, so moved on rather quickly to a protection company, (everything from lv through transmission line stuff, big on distance protection, motor and generation) then a few consulting companies mainly doing fault level, and protection analysis and design and so on.

Having got a bit sick of the technical side (very challenging, but little money or respect) I moved into tech project management - an absolute doddle, but lots of money. I managed installations of turbine generators/CHP schemes around the world.

Sick of working away, back to consulting, but increasingly away from high voltage to installation type stuff over the last 20 years or so.

So a bit of a wide range of stuff!

Been back and forward between consulting, doing, and managing, over the years - it's somewhat more intertwined than the above summary suggests.

Should have retired several years ago, at 55 then savings and personal pensions until 60, then with personal and state pension, but the b#$%@#&$ shifted it to 67 before I get state pension. So just kind of semi-retired waiting for a good point to retire fully.

 

[James]

I think its safe to say that @Julie. Knows a bit about this electricity stuff.

During my career in the engineering and manufacturing industry's
I can only think of 4 Engineers that I consider really good in their field of work (proper engineers, not technicians that call themselves engineers)
3 of them are women, this is an unusual statistic because of how few women work in the engineering field compared to men.

Its hard to say without appearing patronising or sexist but well done to all the women who excel in the field of engineering because there have been and probably still are many obstacles they had to climb to get where they are today, that a man in the same position may not have encountered.

 

[Julie.]

I think its safe to say that @Julie. Knows a bit about this electricity stuff.

During my career in the engineering and manufacturing industry's
I can only think of 4 Engineers that I consider really good in their field of work (proper engineers, not technicians that call themselves engineers)
3 of them are women, this is an unusual statistic because of how few women work in the engineering field compared to men.

Its hard to say without appearing patronising or sexist but well done to all the women who excel in the field of engineering because there have been and probably still are many obstacles they had to climb to get where they are today, that a man in the same position may not have encountered.

As the saying goes, "For a woman to be considered half as good as a man, she has to be twice as good"

Fortunately, such a challenge is easily achieved



Just kidding, but it's kind of an open goal!

 

[pc1966]

I think its safe to say that @Julie. Knows a bit about this electricity stuff.

Yes, full respect deserved there!

During my career in the engineering and manufacturing industry's
I can only think of 4 Engineers that I consider really good in their field of work (proper engineers, not technicians that call themselves engineers)
3 of them are women, this is an unusual statistic because of how few women work in the engineering field compared to men.

Its hard to say without appearing patronising or sexist but well done to all the women who excel in the field of engineering because there have been and probably still are many obstacles they had to climb to get where they are today, that a man in the same position may not have encountered.

I used to teach electronics many years back, and it was always disappointing to see how few women applied to study the degree in the first place as it represents a huge loss of potential talent that has gone elsewhere. That issue is a wider one for school and society to fix, alas.

In 2016 when we (myself and two others from a now-closed facility) to India for a meeting with ISRO we were pleasantly surprised to find that almost half of the 12 predominantly engineering/software folks at the meeting were women. I even made a point of writing to the top guy we had been dealing with to praise their achievement.

 

[James]

As the saying goes, "For a woman to be considered half as good as a man, she has to be twice as good"

Fortunately, such a challenge is easily achieved



Just kidding, but it's kind of an open goal!

You made me laugh out loud then!!

I take it back, maybe you should have stayed as the receptionist, polished your nails, ignored the telephone, and worked part time as a comedian!!

 

[pc1966]

I take it back, maybe you should have stayed as the receptionist, polished your nails, ignored the telephone, and worked part time as a comedian!!

Actually that might have paid me more!

 

[Vortigern]

Anyway @Julie. if you are ever stuck for a bit of cash I could probably use you for a bit of house-bashing when the pension days hit. Clearly you know a bit about electrics. In truth a captivating story. It is surprising the stories there are no doubt on here. Who knew?

 

[OnlQQker]

As the saying goes, "For a woman to be considered half as good as a man, she has to be twice as good"

Fortunately, such a challenge is easily achieved



Just kidding, but it's kind of an open goal!

Ouch..

 

[Julie.]

Actually that might have paid me more!

Anyway @Julie. if you are ever stuck for a bit of cash I could probably use you for a bit of house-bashing when the pension days hit. Clearly you know a bit about electrics. In truth a captivating story. It is surprising the stories there are no doubt on here. Who knew?

I would guess we all have interesting stories, I would further guess a number of them couldn't be shared on a public forum!!!