Oven

Discussion in 'Electricians' Talk' started by mrppp, Oct 12, 2017.

  1. mrppp

    mrppp Member

    If a Oven has its own rcbo circuit, does it still require any other means of isolation nearer the appliance ?
     
  2. Comlec

    Comlec Active Member

    I would say no as an RCBO, according to Table 53.4, is OK for isolation. However, if you think a user might want to switch the oven off for cleaning rather than maintenance then a isolator/functional switch near the appliance might prove useful.
     
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  3. Coloumb

    Coloumb Well-Known Member

    Also check the rating of the rcbo against the final length of flex that feeds the oven - if it's something like 1.5mm then you will need to fused down to 13a on a fcu. And check what the manufactures say, they might require local isolation/fcu too.
     
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  4. mrppp

    mrppp Member

    thanks for this
     
  5. Bazza

    Bazza Well-Known Member

    There is no regulation that says that an oven etc requires local isolation.
    Manufacturer's advice should be heeded.
     
  6. JP.

    JP. Screwfix Select

    I was always under the impression that an oven/hob and other stuff in that ilk always but always required local isolation - you know use the NIC recommended distances of 300+mm from isolator to hob edge and stuff (or use common sense). Never knew you could just negate supply by switching off breaker. Hmmm sp isolation in most cases..will it comply in all cases? Myself I dont think so.
     
  7. mrppp

    mrppp Member

    Reason I ask is I am going for a grid system with its own ring main for all appliances, but that means I cant run the oven through this and would prefer it to be on its own 6mm supply back to a RCBO, thus wondered if it needed local isolation, as having a fcu on the wall kind of gives me what i'm trying to avoid by using a grid system
     
  8. Bazza

    Bazza Well-Known Member

    Thats true of many, i'm afraid. This is usually extra guff thrown in by people like NICEIC (who do NOT write the regulations) and other people who write so-called guides to 'help' the less-well trained electrician do more work that they need to.

    Please go ahead and prove me wrong. Please have a good look at isolation in BS7671 and quote me the relavent regulation numbers......

    I wait, with bated breath:D

    PS Having done a risk assessment, a designer may determine that a double pole isolator is necessary in certain circumstances, but not as a general rule.
     
  9. Comlec

    Comlec Active Member

    JP as we all know the regs from the IET, advice from the NICEIC and Common sense are not always in perfect alignment. But table 53.4 summarises the devices that can be used for isolation, functional switching and emergency switching.
     
  10. Bazza

    Bazza Well-Known Member

    Up to you, you're the designer. I always wonder what was the point of having a spaceship's array of switches to isolate everything including the hamster's exercise wheel. All it conspires to do is to concentrate a whole heap of loads on to one point on what should be a distributed circuit.
     
  11. mrppp

    mrppp Member

    Personally a spaceship's array in a cupboard always looks nicer than FCU dotted around a kitchen, prefer just to see the sockets. Off on Holiday I can be sure everything is switched off too
     
  12. JP.

    JP. Screwfix Select

    ''PS Having done a risk assessment, a designer may determine that a double pole isolator is necessary in certain circumstances, but not as a general rule''

    Concur 100%..;)

    As to the rest Bazz - BS7671 may well say that local isolation is not needed, however mostly that will be overridden by manufacturer stipulations

    Myself I think things are too lax nowadays, dont worry about this, dont worry about that, BS 7671 sais you dont need whatever, just get quick dosh and stick it in ure sky rocket - Old Skool overrides that - this has been proven in the spam the cables thread and now this. No wonder sparks earn megabucks, theirs hardly owt to do when designing and deploying the system..:)
     
  13. Comlec

    Comlec Active Member

    Surely it is down to what the customer prefers or specifies knowing the options.
     
  14. JP.

    JP. Screwfix Select

    Many thanks Mr C - will have a dekko at that table but it really means nowt to me within the parameters of the topic.
     
  15. JP.

    JP. Screwfix Select

    Is it in the osg? what page number is it because I dont like the book much tbqh - handy for some things though.
     
  16. Risteard

    Risteard Well-Known Member

    You sure?
     
  17. mrppp

    mrppp Member

    Customer prefers spaceship's array in a cupboard ;-)
     
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  18. Comlec

    Comlec Active Member

    I use an online version of the OSG and the regs so no page nos.
     
  19. Coloumb

    Coloumb Well-Known Member

    Reasonably so, though no worse than an unfused spur I guess.
     
  20. mrppp

    mrppp Member

    I'm not suggesting having a oven on a spur, it will be on its own 6mm RCBO protected circuit
     

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