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Ovens on cooker ccts

Farmboy
In domestic kitchens, what do you think of the practice of connecting ovens to 32/40A cb cooker ccts via dual cooker connection outlet plates? For example, along with a 6kw hob, a 2.5kw oven is connected via a 1.5mm2 3 core h/r flex? One view is that it's acceptable because the flex can't be overloaded and the cb provides s/c protection for the flex, nor would it be coded on an eicr.


F
  • 0

    what of polarity, and where is the circuit extremity for Zs



    Arguably L-N polarity reversal at an appliance won't be a safety issue to the users of the installation - since CE marked appliances generally have to be safe when connected to systems where there isn't an earthed neutral (230V between phases) or supply polarity isn't guaranteed. Provided it's OK at any single pole devices (e.g. the MCB), arguably there's no real need to check polarity at cooking appliances themselves on an EICR - as we're only required to look for defects and non-conformities that may give rise to danger.


    Likewise if the circuit is RCD protected, there's no need to verify Zs at the furthest point - a simple c.p.c. continuity check (e.g. R2 wander lead) is sufficient - see the last paragraph of 643.71 a) for TN systems or b) for TT systems.


       - Andy.
  • 0

    Chris Pearson:

    How is pulling out an oven, which requires a degree of dismantling; or lifting a hob; or indeed pulling out any other item of fitted kitchen appliances, consistent with GN3 para 3.8.1 Scope: "... The inspection is carried out without taking apart or dismantling equipment as far as possible."?




    Is undoing a few screws in woodwork, that are only there to stop the oven sliding forward when opening the oven door, 'dismantling equipment'? Arguably not, and I would rather pull it out to see if there's some dodgy wiring in behind, than leave it due to an ambiguous guidance statement/term - and it's not doing harm, quite the opposite. Would you not take the tube out of a florescent fitting, and the lid off, to see if there's thermal damage to the wiring, because it's dismantling equipment?


    F

  • 0

    AJJewsbury:




    what of polarity, and where is the circuit extremity for Zs



    Arguably L-N polarity reversal at an appliance won't be a safety issue to the users of the installation - since CE marked appliances generally have to be safe when connected to systems where there isn't an earthed neutral (230V between phases) or supply polarity isn't guaranteed. Provided it's OK at any single pole devices (e.g. the MCB), arguably there's no real need to check polarity at cooking appliances themselves on an EICR - as we're only required to look for defects and non-conformities that may give rise to danger.


    Likewise if the circuit is RCD protected, there's no need to verify Zs at the furthest point - a simple c.p.c. continuity check (e.g. R2 wander lead) is sufficient - see the last paragraph of 643.71 a) for TN systems or b) for TT systems.


       - Andy.

     




    Point taken, thanks.


    F

  • 0

    Farmboy:




    Chris Pearson:

    How is pulling out an oven, which requires a degree of dismantling; or lifting a hob; or indeed pulling out any other item of fitted kitchen appliances, consistent with GN3 para 3.8.1 Scope: "... The inspection is carried out without taking apart or dismantling equipment as far as possible."?




    Is undoing a few screws in woodwork, that are only there to stop the oven sliding forward when opening the oven door, 'dismantling equipment'? Arguably not, and I would rather pull it out to see if there's some dodgy wiring in behind, than leave it due to an ambiguous guidance statement/term - and it's not doing harm, quite the opposite. Would you not take the tube out of a florescent fitting, and the lid off, to see if there's thermal damage to the wiring, because it's dismantling equipment?



    No because that is not part of the fixed wiring. However, I would probably need to take it apart if I needed to measure Zs at the luminaire.

  • 0

    Chris Pearson:




    Farmboy:




    Chris Pearson:

    How is pulling out an oven, which requires a degree of dismantling; or lifting a hob; or indeed pulling out any other item of fitted kitchen appliances, consistent with GN3 para 3.8.1 Scope: "... The inspection is carried out without taking apart or dismantling equipment as far as possible."?




    Is undoing a few screws in woodwork, that are only there to stop the oven sliding forward when opening the oven door, 'dismantling equipment'? Arguably not, and I would rather pull it out to see if there's some dodgy wiring in behind, than leave it due to an ambiguous guidance statement/term - and it's not doing harm, quite the opposite. Would you not take the tube out of a florescent fitting, and the lid off, to see if there's thermal damage to the wiring, because it's dismantling equipment?



    No because that is not part of the fixed wiring. However, I would probably need to take it apart if I needed to measure Zs at the luminaire.


     




    Sorry, do you mean the flourescent is not part of the fixed wiring? Presumably you wouldn't open the door/lid of a rotary switch disconnector to have a look inside either because it's dismantling - which isn't much different from removing the flpurescent lid. I'm not trying to be contrary, just determine where the boundary is between what is reasonable to open up to inspect, and when it's not. 


    Also, according to an article in the PE mag, reg 14 of the EWR 1989, prohibits us from measuring Zs at e.g. Light fittings because it's unnecessarily working live - we have to measure r1+r2 and add Ze instead to determine  Zs


    F

  • 0

    Farmboy:




    Chris Pearson:




    Farmboy:




    Chris Pearson:

    How is pulling out an oven, which requires a degree of dismantling; or lifting a hob; or indeed pulling out any other item of fitted kitchen appliances, consistent with GN3 para 3.8.1 Scope: "... The inspection is carried out without taking apart or dismantling equipment as far as possible."?




    Is undoing a few screws in woodwork, that are only there to stop the oven sliding forward when opening the oven door, 'dismantling equipment'? Arguably not, and I would rather pull it out to see if there's some dodgy wiring in behind, than leave it due to an ambiguous guidance statement/term - and it's not doing harm, quite the opposite. Would you not take the tube out of a florescent fitting, and the lid off, to see if there's thermal damage to the wiring, because it's dismantling equipment?



    No because that is not part of the fixed wiring. However, I would probably need to take it apart if I needed to measure Zs at the luminaire.


     




    Sorry, do you mean the flourescent is not part of the fixed wiring? Presumably you wouldn't open the door/lid of a rotary switch disconnector to have a look inside either because it's dismantling - which isn't much different from removing the flpurescent lid. I'm not trying to be contrary, just determine where the boundary is between what is reasonable to open up to inspect, and when it's not. 


    Also, according to this article in the PE mag, https://professional-electrician.com/technical/determining-zs-for-a-lighting-circuit/ reg 14 of the EWR 1989, prohibits us from measuring Zs at e.g. Light fittings because it's unnecessarily working live - we have to measure r1+r2 and add Ze instead to determine  Zs


    F


     




     

  • 0
    How do you get Ze?
  • Former Community Member
    0 Former Community Member
    How do you get Ze?


    Play nicely!!!!!


    Regards


    BAD
  • 0

    Farmboy:




    Chris Pearson:




    Farmboy:




    Chris Pearson:

    How is pulling out an oven, which requires a degree of dismantling; or lifting a hob; or indeed pulling out any other item of fitted kitchen appliances, consistent with GN3 para 3.8.1 Scope: "... The inspection is carried out without taking apart or dismantling equipment as far as possible."?




    Is undoing a few screws in woodwork, that are only there to stop the oven sliding forward when opening the oven door, 'dismantling equipment'? Arguably not, and I would rather pull it out to see if there's some dodgy wiring in behind, than leave it due to an ambiguous guidance statement/term - and it's not doing harm, quite the opposite. Would you not take the tube out of a florescent fitting, and the lid off, to see if there's thermal damage to the wiring, because it's dismantling equipment?



    No because that is not part of the fixed wiring. However, I would probably need to take it apart if I needed to measure Zs at the luminaire.



    Sorry, do you mean the flourescent is not part of the fixed wiring? Presumably you wouldn't open the door/lid of a rotary switch disconnector to have a look inside either because it's dismantling - which isn't much different from removing the flpurescent lid. I'm not trying to be contrary, just determine where the boundary is between what is reasonable to open up to inspect, and when it's not. 


    Also, according to an article in the PE mag, reg 14 of the EWR 1989, prohibits us from measuring Zs at e.g. Light fittings because it's unnecessarily working live - we have to measure r1+r2 and add Ze instead to determine  Zs



    So are you going to open up every cooker and hob and peer inside; and let's not forget central heating boilers, immersion and storage heaters?

  • 0
    Always take the top of of the immersion heater/s to check the thermostat. 


    Andy Betteridge

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