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Wiring Regulations Literary Question

Former Community Member
Former Community Member
Hello all, I wonder if someone can help me please?

https://en.wikipedia.org/wiki/Voltage_optimisation#Overvoltage

I'm trying to get a reference for a section in this wikipedia article to put in a report I'm writing but I can't find the original source. Under the "Common Power Quality Problems > Overvoltage" section there is a sentence that describes "A 230 V rated lamp used at 240 will achieve only 55% of its rated life". From the article I believe it is from the book "Commentary on IET Wiring Regulations 17th Edition" from 2016, ISBN 1849197652.


I have tried to find it in a library as I don't have £90 to drop on a new copy of it, just to see if it is this book I should be referencing in my report, but I've had no luck there. Is there perhaps anyone with this book that knows whether or not the quote does indeed come from it or not?


Any assistance with this query would be greatly appreciated.

Thanks in advance

Alan
  • 0
    It is extremely unwise to use Wikipedia as any kind of reference source. You are describing a well-known effect on incandescent lamps, they do have huge changes in life with small differences of the supply voltage. I suggest a reference to a manufacturer's data which will give this effect useful data. Try GE entertainment lamps data, for a CP41 or something similar.
  • 0
    Alan S:

    Hello all, I wonder if someone can help me please?

    https://en.wikipedia.org/wiki/Voltage_optimisation#Overvoltage

    I'm trying to get a reference for a section in this wikipedia article to put in a report I'm writing but I can't find the original source. Under the "Common Power Quality Problems > Overvoltage" section there is a sentence that describes "A 230 V rated lamp used at 240 will achieve only 55% of its rated life". From the article I believe it is from the book "Commentary on IET Wiring Regulations 17th Edition" from 2016, ISBN 1849197652.


    I have tried to find it in a library as I don't have £90 to drop on a new copy of it, just to see if it is this book I should be referencing in my report, but I've had no luck there. Is there perhaps anyone with this book that knows whether or not the quote does indeed come from it or not?


    Any assistance with this query would be greatly appreciated.

    Thanks in advance

    Alan


    I seem to recall the statement, the details of which I can't remember. I may have a source book here somewhere, but I can not put my hand on it at present. I will have a search around. My quote may though have been about the energy put in to a filament lamp producing less than 10 per cent light and about 90 per cent heat.


    Z.


     


  • 0
    I have had no luck so far except to find a reference to efficiency. An old 1950 books says that a   ten percent supply Voltage under-run results in a candle-power light reduction of 33 per cent.


    Still looking.


    Z.
  • 0
    from the book "Commentary on IET Wiring Regulations 17th Edition"

    If it's of any help I do have the 16th Ed one. I've had a quick scan of the index and not found anything so far - but it might be lurking in there somewhere still. I'll have a closer look later on.


    I presume you know not to take such comments out of context - incandescent lamps sold in the UK were almost certainly 240V rather than 230V versions regardless of declared voltages and anyway are hardly an issue any more since incandescents are effectively unavailable for general use, while the drivers for LEDs/CFLs are far more tolerant of voltage changes.


       - Andy.
  • 0
    From my book entitled; "Practical Engineer ELECTRICAL Pocket Book and Diary 1910."

    Dr. Fleming in a course of lectures to the Royal Institution showed a series of curves for a 16 candle power 100 Volt lamp. The conclusion reached was that 98 Volts gave 15 candle power. !00 Volts gave 17 candle power. In other words a variation of 2 per cent in the supply Voltage showed a variation of nearly 12 per cent in the light emitted.


    Z.
  • 0
    AJJewsbury:
    from the book "Commentary on IET Wiring Regulations 17th Edition"

    If it's of any help I do have the 16th Ed one. I've had a quick scan of the index and not found anything so far - but it might be lurking in there somewhere still. I'll have a closer look later on.


    I presume you know not to take such comments out of context - incandescent lamps sold in the UK were almost certainly 240V rather than 230V versions regardless of declared voltages and anyway are hardly an issue any more since incandescents are effectively unavailable for general use, while the drivers for LEDs/CFLs are far more tolerant of voltage changes.


       - Andy.


    It may be in a previous edition such as the 15th  edition.


    Z.


  • 0
    You really want a lighting text book like 'Lamps and lighting'  1966 by Hewitt and Vause or similar. That particular example, being the one on my desk, has a nice plot on page 174, showing life, efficiency and power input against supply voltage for a coiled coil filament lamp  and is the sort of library book the commentary writers would have referred to when making their passing comment. For the purpose of academic study or critical review I reckon I can scan the page in tonight without breaking UK copyright law.

    Mike
  • 0
    Like Andy above I have had a quick skim through the last 5 editions of the Commentary and I cannot find anything on lamp life and over voltage.
  • Former Community Member
    0 Former Community Member
    Thanks for the messages and advice all!


    It has been very helpful :)
  • 0
    The "modern" tungsten filament lamp is gas filled. Vacuum lamps  run very hot at about 2,000 degrees C. As it runs hot the filament evaporates. This increases the electrical resistance and reduces light output and current draw. Also the glass bulb becomes blackened and this also adds to reduced light output. If argon or nitrogen gas are added the running temperature can be increased to about 2,500 degree C. The latter requires a coiled coil filament to retain heat and efficiency.


    Z.

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