The IET is carrying out some important updates between 17-30 April and all of our websites will be view only. For more information, read this Announcement

Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 39 replies
  • Subscribers 31 subscribers
  • Views 9413 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Electric cooker switches

Arran Cameron
I hope that this doesn't come across as a daft question...


Why do most electric cooker switches have an in-built socket? Do analogous cooker switches exist in other countries that use different types of mains sockets?


I used to think that the socket was for plugging in a gas cooker electric ignition, but there is no real reason for having a separate circuit from the ring main for this.
  • 0
    In the early days of electricity a new cooker circuit was a major investment. The cooker switch for a 30 Amp circuit for a new electric cooker would contain a socket outlet for a kettle. As the cooker was normally located near to a work surface in the kitchen a kettle could be located right next to the cooker. The new cooker switch being located just to one side of the new cooker switch. This provided a convenient economical supply for a kettle or toaster etc. as well.


    C.
  • 0
    This link shows an old cooker control switch and 13 Amp socket dating back to perhaps the 1960s. Older units had round pin socket outlets that pre-dated this M.K. example.
    https://www.flameport.com/electric_museum/cooker_controls/mk_cooker_control.cs4


    C.
  • 0

    Arran Cameron:

    I hope that this doesn't come across as a daft question...


    Why do most electric cooker switches have an in-built socket? Do analogous cooker switches exist in other countries that use different types of mains sockets?


    I used to think that the socket was for plugging in a gas cooker electric ignition, but there is no real reason for having a separate circuit from the ring main for this.




    Well now, if it was a gas cooker, you wouldn't need an electricity supply for it; and I suspect that gas cookers were lit by matches when these sort of accessories were introduced.


    I simply don't buy the idea of using the socket for a kettle - that would have gone on the stove.


    The more I think about it, the sillier it seems. No there is no need for a socket to be included in the cooker circuit.


    As for overseas, I doubt that they would use such an arrangement because a cooker circuit might be 32 A and in the absence of a fused plug, the flex of an appliance would not be protected. In France, for example, there would be separate circuits for the cooker, dish washer, washing machine, etc.


    See how clever the BS1363 system with ring final circuits is!

  • 0

    BS1363 sockets were first manufactured in the late 1940s, so any older cooker switches with in-built sockets would have had a BS546 round pin socket. Did these actually exist, and if so, what was the usual current rating of the socket? Were cooker switches ever manufactured with the competing Wylex and Dorman Smith sockets?



    I have been verbally informed that the purpose of the socket was provide a dedicated supply for small electric hobs and ovens that consume less than 13A in order to reduce the current load on the ring main. The socket is also ideal for other high current appliances such as washing machines or electric heaters that would have been plugged into a 15A BS546 socket. Is this true? I don't buy into the argument that the in-built socket in a cooker switch was intended for the kettle or the only socket in the kitchen. BS546 sockets were already installed in kitchens, and in houses with gas cookers and no electric cooker supply BS1363 sockets in the kitchen were wired into the ring main.



    Gas cookers with electric ignition only became available in the 1970s, so plugging them into an in-built socket on an electric cooker switch is probably one of convenience of cable routing than anything else. When electric cooker switches with in-built sockets first started to be installed gas cookers were lit with matches or pilot lights.



    What is the official and correct way to connect a separate fitted electric hob and oven to a mains supply?


  • 0

    Why do most electric cooker switches have an in-built socket?



    I'd suggest that today most don't - simple DP 32A or 45A switches seem to be a far more popular choice these days.


    Traditional cooker control units do include a socket - usually 13A but I recall my grandmother having one with a 15A round-pin socket - the unit has a built-in 15A cartridge fuse to protect it.


    I suspect that switching to electric cooking went hand in hand with the introduction of the electric kettle (as a conventional hob kettle would have been painfully slow on the old resistive electric rings) and as many homes in the 1950s, 60s and 70s still wouldn't have caught up with the new fangled ring circuit there often weren't many general purpose sockets about, especially in kitchens where electric appliances would previously have been a rarity, Since you'd have to run a new circuit to the kitchen for the new electric cooker, it makes sense to use the same circuit for a socket as well, rather than having to run two new circuits. Of course the socket was then used for all sorts of kitchen appliances, not just kettles, but in my experience, it was usually the kettle that went there (despite the regular hazard of the kettle flex laying across a hot ring).


      - Andy.
  • 0

    Andrew Jewsbury:


    I'd suggest that today most don't - simple DP 32A or 45A switches seem to be a far more popular choice these days.

    Cooker switches with in-built sockets are still very much mainstream items produced by most manufacturers of electrical accessories; available in numerous styles and finishes; and sold by every DIY and consumer grade electrical shop - unlike clock connectors or 13A sockets with different shape earth pins that are only sold by specialist electrical suppliers.



    Traditional cooker control units do include a socket - usually 13A but I recall my grandmother having one with a 15A round-pin socket - the unit has a built-in 15A cartridge fuse to protect it.

    Therefore it's possible that cooker switches with in-built sockets predate BS1363 although without examining the item it could in theory be made after BS1363 as BS546 plugs and sockets are still being manufactured today. Yes, it would have to have a fuse for the socket. Was the fuse replaceable from the outside like on an FCU?

    I suspect that switching to electric cooking went hand in hand with the introduction of the electric kettle (as a conventional hob kettle would have been painfully slow on the old resistive electric rings) and as many homes in the 1950s, 60s and 70s still wouldn't have caught up with the new fangled ring circuit there often weren't many general purpose sockets about, especially in kitchens where electric appliances would previously have been a rarity, Since you'd have to run a new circuit to the kitchen for the new electric cooker, it makes sense to use the same circuit for a socket as well, rather than having to run two new circuits. Of course the socket was then used for all sorts of kitchen appliances, not just kettles, but in my experience, it was usually the kettle that went there (despite the regular hazard of the kettle flex laying across a hot ring).

     

    If that is the real explanation behind cooker switches with in-built sockets then it makes one wonder whether they are an eccentric, or even grotesque, relic from a previous era that has become ingrained as mainstream technology right up to today. There's not a lot else that a cooker switch with an in-built socket can be used for because most don't have a fuse for the cooker outlet like on a FCU. Twin FCU or a combined FCU and socket, that can replace a cooker switch, don't appear to exist.
  • 0
    I believe you now need a dedicated supply for a new cooker installation with its own circuit breaker at the fuse box. There’s also a switch in the kitchen to isolate it when removing or fitting a new cooker. I don’t know why a quick safe dedicated 32amp appliance  connector  wasn’t developed to stop people botching up this. I was horrified to see the original state of the cabling when my kitchen was replaced.
  • 0
    I`ve always understood it was for occasional use of a kettle. At a time when sockets were few, i.e. one per household or one on ground floor and one on first floor. It made sense to fit this scoket by incorporating it to a cooker circuit. That`s why we diversify the kettle to 5amp because it aint running for long.


    Now a washer or dryer is a whole new ball of wax and best not allowed.
  • 0

    Was the fuse replaceable from the outside like on an FCU?



    Yes - very much like lightly large FCU's fuse carrier as I recall. It was from the era when 13A sockets were available, but I guess they went for a 15A version for 'compatibility' (of sorts) with the rest of the house which was all still round-pin.

     

    Cooker switches with in-built sockets are still very much mainstream items



    Certainly still available - but I still suggest comparatively rarely selected (far less than 50% that would be needed for a 'most' category) - it's literally decades since I've seen a new or refurbished kitchen get one. They seemed to start to fall out of favour under the 16th - in the days of half-RCD protected split boards - if the socket could be used for equipment outdoors (which always seemed likely for a ground floor kitchen) then the cooker circuit would have to be on the RCD side along with all the socket circuits, so risked overloading the typically low rated RCDs of the time. Consumers never seemed to appreciate the engineering and convenience of having a decent amount of wiring space behind them and usually regarded them as big and ugly compared to a simple (usually 1G) DP switch. Now the vast majority of kitchens can have a decent number of general purpose sockets on their own circuit, the need for a cooker unit with a socket is quickly diminishing, and yes I expect them to go the way of clock connectors.


      - Andy.
  • 0

    Martin Hutson:

    I believe you now need a dedicated supply for a new cooker installation with its own circuit breaker at the fuse box. There’s also a switch in the kitchen to isolate it when removing or fitting a new cooker. I don’t know why a quick safe dedicated 32amp appliance  connector  wasn’t developed to stop people botching up this. I was horrified to see the original state of the cabling when my kitchen was replaced.




    Any appliance that consumes more than 13A cannot be powered from a ring main, and has to have its own dedicated supply. Ideally any fixed appliance consuming more than 10A should have its own dedicated supply. The modern practice is for houses to have a kitchen ring main separate from the downstairs ring main which somewhat reduces the requirement to have dedicated supplies for higher current appliances.


    An older neighbour replaced a full sized electric cooker when her kitchen was refurbished with a two element hob and small oven combo. It plugged into the socket on the cooker switch although this decision was probably more one of convenience of location rather than for technical reasons. Therefore I can't help wondering if that is actually the real reason for the socket. 



     

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines