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Oven & hob on 13amp fused spur

Former Community Member
Former Community Member
I’ve come across an electric oven and gas hob on a cooker circuit, the cooker switch feeds a 13a fused spur which powers both the Oven & hob, hard wired into a 32amp junction box.
the oven is rated at 13 amps but the hob 3 amps Is this acceptable as the hob is protected by a 13 amp fuse?

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  • 0
    Actually Mike it will carry 13A for ever, it may get rather warmer than one likes, but will not fail open circuit. After an hour or two it will get to something under 100degrees. It will not melt or anywhere near. The PVC will slowly lose the plasticiser, so the cable will become stiff, and at some point will be brittle enough to crack, but, it will take a long time. In your car cables carrying 15A for long periods are often 0.75mm2, the BS7671 ratings are very conservative, and ignore the time variable (which is important) completely. Calculate the actual power loss (Watts) and think about it very carefully. The temperature rating is about life, not failure. How long does a few watts take to boil a small cup of water? Similar problem...
  • 0
    ebee:

    A 3 Amp hob won`t cook much will it Tom?


    Hello Ebee!!


    The hob is gas and it uses the required electrics for 'ignition' only. So, nothing much in wattage?


    I was thinking, (not a good point, for me, I know, haha), maybe remove the JB and fix a 'dual' pattress so one side can be fitted with a Sw't spur and the other with a plug top OR, 2 x switch spurs??? 


    regards... Tom


  • 0
    What is the size of the cable, feeding the JB?


    0.75mm2 is rated at 6 amps... I know this isn't feeding the JB!
  • 0
    Tom,


    "ebee:

    A 3 Amp hob won`t cook much will it Tom? "


    Was a little bit of a tongue in cheek sort of quip, you know me ?
  • 0
    ebee:

    Tom,


    "ebee:

    A 3 Amp hob won`t cook much will it Tom? "


    Was a little bit of a tongue in cheek sort of quip, you know me ?


    Hello Ebee...


    I've always loved your posts', Ebee!! ?


    You've always been a great source of info, keep up the great work!! ?


    Good luck, for 2021!!


    regards... Tom


  • Former Community Member
    0 Former Community Member
    Tomgunn:

    What is the size of the cable, feeding the JB?


    0.75mm2 is rated at 6 amps... I know this isn't feeding the JB! 


    6mm (or possibly 4mm) feeding to the Fused spur, then 2.5mm to the JB the circuit is protected by a 20a MCB


    To complicate matters the cooker circuit has been turned into a radial circuit as there is also a socket outlet which is used for a fridge


    The socket outlet is on 2.5mm I guess this is why the circuit has a 20a MCB  


    So its CU 20a MCB  >>> Cooker Switch with socket (switched side feeding 13a fused spur for oven / hob ) >>> Socket outlet


  • 0
    Its all just fine then.
  • 0
    Well the MCB could have been left at 32A - we do not worry about a socket on 2.5mm when one double socket is a spur on a ring after all, only if there  is a whole string of sockets, however, on a 20A radial  you could have as many sockets and 13A fused spurs as you like.

    However, I think it makes no difference to the original conclusion,( I'm with Dave on this one), there is no credible fault condition that is not covered, it may not be what you expected to see, but it is certainly fine.

    Mike.
  • 0
    I agree with others in that there is not a safety issue. However it is a rather untidy arrangement, and not within the spirit of the Wiring Regulations, let alone the letter.


    I am not keen on hard wiring appliances to the permanent mains wiring. If two spur points were provided, then it would be easy to remove either the oven or the hob for servicing. Even consider two 13 A sockets that the appliances would plug into. Quicker and easier still to remove for servicing.
  • Former Community Member
    0 Former Community Member
    Denis McMahon:

    I agree with others in that there is not a safety issue. However it is a rather untidy arrangement, and not within the spirit of the Wiring Regulations, let alone the letter.


    I am not keen on hard wiring appliances to the permanent mains wiring. If two spur points were provided, then it would be easy to remove either the oven or the hob for servicing. Even consider two 13 A sockets that the appliances would plug into. Quicker and easier still to remove for servicing.


    I totally agree with the idea of 13a sockets, but the oven manual states that it must be hard wired to a Circuit with 13a protection, And wired with a minimum 4.0mm three core cable or T&E


    The oven is rated at 2200W, why would they consider 4.0mm as the minimum, surely 1.5mm would be acceptable?

     


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