Oven/ Hob Cable sizes

Discussion in 'Electricians' Talk' started by Wheel-nut, Feb 1, 2004.

  1. Wheel-nut

    Wheel-nut Member

    I am re-fitting my Kitchen with a Double Oven and separate Hob. I intend to put the Hob on the existing 6mm cooker point which is fed from a 40A Wylex Plug-in MCB. The Hob is a Belling CTC465 with a total load of 7.7KW.

    The Double Oven is a Belling XOU487 with each oven rated at 2.58KW giving a total load of 5.16KW which is 22.4A @230V. I have a 2.5mm T&E cable available for this without having to dig up the walls and floor! The appliance is only a metre from the CU so Volt Drop should be minimal.

    What is the current maximum current permissible on 2.5mm T&E? My tables say 24A if protected by Type B MCB. Is this correct?

    BR and B-A-S can you advise...
  2. The Trician

    The Trician New Member

    TABLE 4D5A in BS7671 states that the rating for 2.5mm T+E is 21A when installed directly into an insulated wall.
    Which table(S) are you using?
    Hope this helps
  3. Wheel-nut

    Wheel-nut Member

  4. The Trician

    The Trician New Member

    I reckon that 2.5 is too small:( So its time to drop some 6.00mm in instead:) Not sure, without looking it up, that you are allowed any diversity on an all-in-one 4 ring cooking appliance, but if you're not, then a new larger cable is the order of the day.
  5. supersparky

    supersparky New Member

    i think you can apply diversity, your unlikly to use all elements, but as its a stud wall cant you drop down a 6? thats what i would do, i think it would be fine on 2.5, BUT if it was a job id change it to 6mm, you could put it on a 20amp breaker, type c, which will stop you for overloading the cable, yet will allow for the initial start up

    Btw, got the plugins then?

  6. Wheel-nut

    Wheel-nut Member

    Thanks Trician and BR.

    The Hob is a 5 ring unit and will be on the 6mm feed so no problem there.

    Each Oven is rated at 2.58KW and I think that diversity could apply because the Thermostats will cut in and out once the oven is up to temperature. The load is only marginally over the cable rating at worst case (230V) so what do you reckon?

    BR, Yes, I would still like the Plug-ins if you have them. I have been away in warmer climes, dipping my toes in warm salty water. Drop me an e-mail when you have them.
  7. The Trician

    The Trician New Member

    I'd still put bigger cable in - what's to stop both ovens being switched on from cold at the same time? It would be quite a while before you could rely on the stats to 'float' the current draw and all this time you cable will be getting warm. No probs with damp in your walls though!!
  8. bilco

    bilco New Member

    They are high ratings for a double oven. Isn't one including a grill load which would extend diversity somewhat.
  9. Wheel-nut

    Wheel-nut Member

    Oh ****.... I have just noticed that the Grill is rated at 2.7Kw.

    Oh Well, time to get the hammer and chisel out. 6mm it is then!
  10. Legal Sparrow

    Legal Sparrow New Member

    Do you need a special cable to connect the cooker to the wall plate.

    The instructions on mine mention a code for the cable (don't have it to hand). Could it be a special heat resistant cable rather than a regular one?

Share This Page