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Appliance Ratings and 13A plug tops

statter
Hello

I looked last year for portable heating and not surprisingly there was little above 2.5kW rating.  All the old 3kW stuff has long gone.

I was surprised however to find a wide range of steam irons rated at 3000W and even 3100W.  (that's almost 13.5A at 230V).  I realise of course that irons are likely to be much more intermittent than heating and that 13.5A is very unlikely to blow a 13A fuse but it cant be good practice to overload plug/ socket like this.  A decent ironing session can still be hours ……   OFC at 240v its under 13A but 230v has been the standard for ages now.   In my experience many socket/ plug combinations are marginal approaching their rating so deliberate overloading will only make matters worse over time.  I would have thought that these appliances wouldn't qualify for CE marking and couldn't be sold legally?  Does anyone know if there is a BS or EN for small appliances?


Thanks


Peter
  • 0

    GeorgeCooke:



    . . .
    It's really probably energy efficiency - oil-filled and halogen devices are cheaper to run than a 3-bar fire or the "snail fan and coil" type heaters.


    All electrical heaters are 100% efficient. If it uses a kW of electricity it gives out a kW of heat whether it is an oil filled radiator, fan heater or bar fire.




     

    I think we need to distinguish between efficiency and effectiveness. You do not benefit from the heat of a convector heater until it has had time to warm up the  whole room (unless you can find a way to baffle the rising warm air towards you, e.g. under a table where you are seated).


    A radiant heater quickly gives some benefit if you are nearby because you soon pick up the radiant heat from it - the next best thing to being in a warned-up room. A fan heater can give quick benefit too if you direct it towards you from nearby. If you need to move about neither of these gives much benefit over a convector heater until the room has warmed up.


    As for oil-filled radiators, they are good on safety considerations, but they take time to warm themselves up before the convection process becomes fully functional, so they are arguably less effective. They have their uses, however.
  • 0

    Denis McMahon:

    Another jargon term is "luminaire" for light fitting.



    Or just plain French. As far as I can determine, "une prise" is used for both a plug and a socket.
  • 0

    Chris Pearson:




    Denis McMahon:

    Another jargon term is "luminaire" for light fitting.



    Or just plain French. As far as I can determine, "une prise" is used for both a plug and a socket.

     




     

    If you want to see the French aspect of this discussion, then this site is interesting reading.

    https://fr.wikipedia.org/wiki/Prise_%C3%A9lectrique


    This seems to confirm Chris's point: just as we over here sometimes hear power sockets referred to as "plugs", something similar happens in France. They do have a proper word for it - le socle.


    However I can see no mention of le sommet de la prise.
  • 0

    Denis McMahon:




    Chris Pearson:




    Denis McMahon:

    Another jargon term is "luminaire" for light fitting.



    Or just plain French. As far as I can determine, "une prise" is used for both a plug and a socket.


     

    If you want to see the French aspect of this discussion, then this site is interesting reading.

    https://fr.wikipedia.org/wiki/Prise_%C3%A9lectrique


    This seems to confirm Chris's point: just as we over here sometimes hear power sockets referred to as "plugs", something similar happens in France. They do have a proper word for it - le socle.


    However I can see no mention of le sommet de la prise.


    Ah but a cache-prise is a socket cover. ?


    That Wikipedia article muddies the waters a treat. Mon dictionnaire tells me that un socle is a base or plinth, which has perhaps come to mean an electrical socket by association with a pattress box. Le dictionnaire de l'Académie Française tells me that the derivation of the word is by metonymy from something which captures (think la prise des la Bastille) something else and that une prise is the female bit which is attached to the fixed wiring.


    Une fiche (feminine noun, but male bits) may be used for a whole plug, or just the prongs.


    I shall seek further advice.

  • 0
    Thanks Chris for your continued investigation, but what is good enough for l'Académie Française is good enough for me.
  • 0

    broadgage:



    3Kw heaters are still available but are marketed as being for industrial use and are therefore supplied without a plug. No warranty claims about melted plugs if plug not supplied. 



    An electrician told me that manufacturers stopped making 3KW heaters for the domestic market back when legislation required appliances to be sold with a mains plug. To use a BS1363 plug continuously on 13A is pushing it to the limit. 3KW heaters were originally designed to be used with a BS546 15A plug.


    The electrician recommends BS546 15A sockets on dedicated circuits with a 16A MCB for high powered heating appliances but they are very uncommon in houses and the public generally doesn't even know that they exist.
  • 0
    A 3 kW heater at 240 V uses 12.5 A (at 240 V) and has a resistance of approximately 19.2 A


    Exactly the same device with the same heating element, rated for 230 V, would have 2.75 kW on its rating plate!


    So perhaps that's another reason.


  • 0

    An electrician told me that manufacturers stopped making 3KW heaters for the domestic market back when legislation required appliances to be sold with a mains plug. To use a BS1363 plug continuously on 13A is pushing it to the limit. 3KW heaters were originally designed to be used with a BS546 15A plug.



    From what I recall from the writeups of the discussions that led to the 13A plug & socket - originally a 10A outlet was proposed but that was objected to because of the 3kW heaters commonly in use in parts of the country. So the 13A plug (originally 3120W@240V) was certainly  intended to be able to supply 3kW heaters.


    Maybe the move to moulded-on plugs that presumably must be made of thermoplastic rather than thermosetting material started the decline.


       - Andy.
  • 0
    This plug (with bottom, sides, and top) was on a 3 kW heater. I suspect that the over-heating may have been in part due to inadequate insertion leading to arcing. I cannot see why the pins would run so much hotter than the cable.

    64b910ad89036808571a4cb8353fcad1-huge-20200226plug.jpg

  • 0
    Interesting that both pins got very hot (well probably over 70C). I wonder what the pins are made of, perhaps high resistance material. Brass is expensive now! I don't see much sign of arcing on the pins, they usually get discoloured and pitted if this happens. Did the socket survive the onslaught?


    A quick addition

    I used to have an MK safetyplug on my 180A stick welder, perhaps a 10 kW appliance with a solid fuse fitted. It never overheated despite some fairly heavy and extended use. Products today are just plain useless, but made to BS EN standards of course. Hm something is wrong in the state of Denmark!


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