[Gareth
Andrew T, may I ask what your occupation is?
Perhaps I will tell you a little something about mine own. I work for the largest Electrical Supply company in the UK. As such I install all varieties of electrical equipment, from basic single-phase 230Volt supplies up to 132,000Volt, above that I do not.
If you would like photographic evidence taken over a time span of, what, one week then I am sure your views will change on frequency variation. When it does vary it is less than 5%. If needed I can take photographic evidence of main supply panels to support this, over a period of weeks if necessary, time and dated.
Digressing, previously you stated that you could write a book about fuses (in another thread here) and how they rupture and on that occassion I pointed out where you were wrong, earth and fusing i.e. fuses have nothing whatsoever to do with earth, if fuses were used in cinnection with earth then the world would become a dangerous place. Personally I would like to read if you do write it this book and so would a lot of my colleagues, then maybe we can change the way electricity is distributed throughout our country.
Please it is my job to stop people, like yourself, from getting killed. I do this everyday.
I would not want to criticise you and your knowledge of electronics, which from what I have read is pretty good. My comments when posted are to help people who do not understand.
Thankyou
Gareth
AndrewT said:
Andrew T, may I ask what your occupation is?
Perhaps I will tell you a little something about mine own. I work for the largest Electrical Supply company in the UK. As such I install all varieties of electrical equipment, from basic single-phase 230Volt supplies up to 132,000Volt, above that I do not.
If you would like photographic evidence taken over a time span of, what, one week then I am sure your views will change on frequency variation. When it does vary it is less than 5%. If needed I can take photographic evidence of main supply panels to support this, over a period of weeks if necessary, time and dated.
Digressing, previously you stated that you could write a book about fuses (in another thread here) and how they rupture and on that occassion I pointed out where you were wrong, earth and fusing i.e. fuses have nothing whatsoever to do with earth, if fuses were used in cinnection with earth then the world would become a dangerous place. Personally I would like to read if you do write it this book and so would a lot of my colleagues, then maybe we can change the way electricity is distributed throughout our country.
Please it is my job to stop people, like yourself, from getting killed. I do this everyday.
I would not want to criticise you and your knowledge of electronics, which from what I have read is pretty good. My comments when posted are to help people who do not understand.
Thankyou
Gareth
I said " I do not want to write a book, That is completely different to "I can write a book".gareth said:
I know I can't.
I was trying to convey the idea that I did not want to start writing a long reply to an experienced reader if it was not necessary for the discussion developing in that other thread.
BTW.
The fault current flowing to earth via the Safety Earth connection can be, or at least approach, kA. How a professional in the field of electricity distribution can state "Earth and fuses" are not linked is beyond me.
As I understand it, the Earth return impedance has a major bearing on the fault current that can flow and that in turn directly influences the speed of rupturing of the fuse in the fault condition.
I believe there is some guidance, maybe even a rule or two, covering maximum Earth return circuit impedance and equipment fault voltage in the 16th edition. You can probably quote from memory for us.
AndrewT said:
Andrew, please, you are getting out of hand here. As you said in your personal e-mail that you sent, you were a Civil Engineer (Concrete and steel not anything remotely connected to Electricity) and now you teach Craft, Design and Technology.
This is a pointless argument as you cannot be taught anything that may help you and any other people that you hand out information to.
May I strongly suggest that you actually go to college and learn about this subject.
As for the varying supply frequencies that the Electricty Supply companies use to apparently accomodate current demand by consumers, then my offer of photographic evidence (timed and dated) still stands. If need be these photos will be taken over a period of a week to a month, whatever suits you Andrew.
If you want me to write you a short book on fuses and their intrinsic behaviour then I will gladly do this for you, free of charge, and with more references grounded in actual Electrical Engineering than you will have heard of.
As to fault currents flowing, got to college and learn.
If you want quotes from the 16th Edition, fine ask away, I'll even quote you the 17th Edition BS7671.
Please Andrew, do not teach me about my job. You do not have the knowledege.
Gareth
PS...as I stated in the e-mail reply I sent to you, this is a forum where knowledge and ideas can be exchanged. Where we can learn from each other.
Current UK mains frequency:
Current UK mains frequency
If you watch it for a few minutes you'll see quite a bit of change (although it seems to stay between 49.9Hz and 50.1Hz for most of the time)
Current UK mains frequency
If you watch it for a few minutes you'll see quite a bit of change (although it seems to stay between 49.9Hz and 50.1Hz for most of the time)
Yes, if mains frequency was radically adjusted at the generator then we would have millions of electric motors running at the wrong speeds, industrial plants would have an absolute nightmare and not too mention the Health and Safety factor, personally I would not want to get pulled into a 3phase 10,000 horsepower motor. Also we would have lots of noisy (buzzing) transformers around the place.
(A good way to check this out is if you have (like I do) an old reel-to-reel tape deck that has switchable frequency, from 50 to 60Hz. If you have one handy then try this, but don't do this if the frequency selector also changes the voltage at the same time.)
Variable frequency control is used though, but locally i.e. on motor control gear so that speeds can be varied. Not all motors use this as only certain types of motor are suitable.
Gareth
(A good way to check this out is if you have (like I do) an old reel-to-reel tape deck that has switchable frequency, from 50 to 60Hz. If you have one handy then try this, but don't do this if the frequency selector also changes the voltage at the same time.)
Variable frequency control is used though, but locally i.e. on motor control gear so that speeds can be varied. Not all motors use this as only certain types of motor are suitable.
Gareth
The Canadian province of Ontario has always been proud of it's accuracy. We USED to be in the 0.0000x% and less range of accuracy on the 60hz. I could be confused about such things, but this was taught to me by my old electronics prof, who was one of the creators of 'The Dew Line' the radar line way up north from here, in Canada.
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