How many Circuits do we need?????

Discussion in 'Electricians' Talk' started by Mad Architect, Apr 17, 2015.

  1. Mad Architect

    Mad Architect New Member

    We have just been sent over a load of extra's from a contractor on a cellar conversion we are doing and it seems a little over kill to me?

    1 Fuse spur for alarm
    1 Fuse spur for TV booster
    1 x 20 amp circuit for heat light
    1 x 20 amp circuit for oven
    1 x 20 amp circuit for steam oven
    1 x 20 amp for warming draw
    1 x 20 amp for hot tap
    1 x humidity fan – not on drawings
    Using bigger mains board – originally it was 4 way now I need 12

    Does each of the appliances require a seperate 20amp circuit? Also, does anyone have any idea what a humidity fan is? Finally, why the jump from a 4 to 12 mains board?

    Mad
     
  2. Lectrician

    Lectrician Screwfix Select

    Without knowing the loadings, there is no way to say. Need to know makes/models etc.
     
  3. stateit

    stateit Screwfix Select

    Seems reasonable to me.

    Appendix 15, giving guidance on Reg 433.1.103 suggests loads of over 2kW should be on their own dedicated circuit.

    Hence oven, steam oven, hot tap, heat light on their own circuit.
     
  4. retiredsparks

    retiredsparks Super Member

    I was under the impression that the 'architect' specified what was to be done....for their large fee ?
    or at least understand the very basics of the building work they are designing...or am i just old fashioned.
    RS
     
  5. peter palmer

    peter palmer Screwfix Select

    The only person that can spec things like this is the electrician, I would not be taking instruction of anyone else when it comes to designing circuits.

    Obviously ovens need their own circuit, I would also put a dedicated 20A in for a hot tap although I have seen plenty plugged into the kitchen ring circuit. Warming drawer probably just of the ring though. Don't know what the heat light is though.
     
  6. stateit

    stateit Screwfix Select

    Now then RT, behave yourself. You know full well you're having a laugh...
     
    KIAB likes this.
  7. retiredsparks

    retiredsparks Super Member

    You are right stateit........must have had a mental aberration.
    I must stop expecting people on thousand of pounds a week to know what they are doing...lol
    RS
     
  8. retiredsparks

    retiredsparks Super Member

    Actually Peter these things, contracts of any substance, are designed by Electrical Design ENGINEERS......the electrician reads the drawings and specifications and installs to that specification.
    RS
     
  9. Coloumb

    Coloumb Screwfix Select

    Looks pretty good to me. It can't be much more expensive to upgrade to that many anyway.
     
  10. seneca

    seneca Screwfix Select

    Or if it's an electrician that knows what he's doing he can do the design work himself!
     
  11. spinlondon

    spinlondon Screwfix Select

    I recently worked in some apartments, where a 2 bed flat had 18 light circuits.
    2 in each bedroom, 3 in each bath/shower room, 2 in the hall, 2 in the kitchen dinning area and 4 in the living area.
    There was also a 4mm RFC on a 32A breaker for Fan Coil Units and wardrobe power supplies.
     
  12. stateit

    stateit Screwfix Select

    That one probably was designed by an architect...
     
  13. retiredsparks

    retiredsparks Super Member

    On a 'decent' sized project, the Electrical Design Engineers (in conjunction with the client and other disciplines) put together a specification ....then put it out to tender.
    There are usually modifications and feedback from the contractors.
    RS
     
  14. Owain

    Owain Member

    That's the problem with mains halogen spotlights.
     
  15. JP.

    JP. Screwfix Select

    ''Obviously ovens need their own circuit''

    What all ovens? Where in the regs does it say that all ovens should be on there own circuit Mr Palmer?..:D
     
  16. spinlondon

    spinlondon Screwfix Select

    Dimmible LCDs.
     
  17. peter palmer

    peter palmer Screwfix Select

    ''Obviously ovens need their own circuit''

    What all ovens? Where in the regs does it say that all ovens should be on there own circuit Mr Palmer?..:D


    Not everything has to come down to the regs, there are things that are acceptable in the regs that I wouldn't do, like run a cable horizontally 6" from a ceiling, I wouldn't run one 6" from a vertical corner either, but I would go tight into one. And there are things it forbids that I would do, like power a cooker hood in 1mm from a spur.

    Its obvious to me that an oven needs its own circuit for practicality reasons, it may be on for an hour or more, in that time the washer or dryer could go on as well as the kettle etc. Although not dangerous there is a lot more chance of the 32A MCB tripping, dinner would be ruined because the woman won't know how to reset the mcb or the oven clock. In contrast a microwave will be on for only a few minutes.

    You dont have to do everything you are told in this life.
     
    seneca likes this.
  18. Mr Rusty

    Mr Rusty Screwfix Select

    20A circuit for a warming drawer?? I'm looking at these and they are only 400-800w max
     
  19. Lectrician

    Lectrician Screwfix Select

    The warming one is the only one I would question, although, a 4mm 32amp circuit could supply a couple of the 13amp appliances via FCU's, rather than loads of individual circuits.
     
  20. unphased

    unphased Screwfix Select

    Warming 'draw'. :rolleyes: drawer
     

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