Suitable CU

Discussion in 'Electricians' Talk' started by snipper1, Jan 28, 2004.

  1. snipper1

    snipper1 New Member

    Hi,
    Having decided through no real choice to replace all the wiring in the house i need to choose a suitable CU.
    I`ve been looking at CU split load kit box (S/Fix D82204)

    UPSTAIRS
    I have 7 double sockets and 5 lights

    DOWNSTAIRS
    10 doubles 9 lights, x1 electric shower unit, x2 fire alarms, 40A cooker and a load of 12V lights in the kitchen units

    OUTSIDE
    Garage consumer unit with 4 doubles and x3 tube lights

    Please help me decide.
     
  2. supersparky

    supersparky New Member

    id use a 12 way mk sentry-splitload
    UPSTAIRS
    I have 7 double sockets and 5 lights
    u/s sockets on 32amp ring

    DOWNSTAIRS
    10 doubles
    Put all sockets on a 32amp ring and put kitchen sockets on their own 32amp ring
    9 lights
    Put these on a 10 amp breaker(circuit wired in 1.5)

    x1 electric shower unit,
    this on own circit
    x2 fire alarms
    Put these on their own dedicated 6 amp circuit
    40A cooker
    run 10mm cable and put in a 45amp breaker
    and a load of 12V lights in the kitchen units
    these can come off a fcu from the kitchen ring

    Before you do this are YOU SURE! you are compitant to do a cu change?
    its something i would NOT consider DIY

    SS
     
  3. Sam Dingle

    Sam Dingle New Member

    How about the Wylex one it's a bit more expensive but better quality.

    Do you realise you'll have to pull the main input fuse which means you'll be breaking the electric boards seal!
     
  4. snipper1

    snipper1 New Member

    I`m only getting things together......replacing wires etc
    the connection to the main - CU will be done by a electrician.
    One thing i found interesting is 1.5mm cable for down stairs lighting.....can you explain the reason ?
    And what if the kitchen lighting is on its own mcb as there are x2 main lights x1 cooker hood/light & several 12v cabinet low lights
     
  5. supersparky

    supersparky New Member

    because your d/s lighting is a large load, should go on a 10amp mcb, if you use a 10 amp mcb you must use 1.5mm cable....
    you should be using 1.5 for lighting anyway, you wont find many sparks that will wire a complete lighting circit in 1mm

    cooker hood should be off a Fcu off the kitchen ring NOT the lights so 2 lights in kitchen is fine, under pelmet would probrabley be best on a fcu off kitchen ring.

    SS
     
  6. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Go with me old china plates post on an MK sentry board,total Rolls-Royce of fittings

    My secound would be MEM,Wilts do some good deals on split load boards with 8 type b breakers.....
     
  7. Damocles

    Damocles New Member

    Also you should stand a better chance of not having the lights all go out when a bulb blows if you use a 10A circuit rather than a 6A one. 10A/1.5M cable will hardly cost anything more but will give you more scope in the future if you want more lights.
     
  8. jomed

    jomed New Member

    When I compared plastic MK with Wylex recently MK enclosures looked rather flimsy. So I've fitted Wylex units which seem more robust.

    Some good deals can be had on made up split-load Wylex units - but as Damocles knows I am not a fan of split load units.
     
  9. Damocles

    Damocles New Member

    well jomed reckons everything should be protected by a RCD, for maximum safety. i reckon different circuits have different uses,and some equipment should not be switched off automatically unles it is absolutely essential for safety reasons (e.g. lights,freezers).

    i dont think we would disagree that both these are good aims of power supply design. The problem is that it becomes very expensive to protect everything independantly and so there is a difference of opinion over what is the best thing to do.If you are only willing to buy one RCD, he reckons it should cover everything. I reckon it should not cover lights and maybe a dedicated freezer socket,but would apply it to everything else. It is possible to buy secondary RCD breakers for subsidiary circuits, and I reckon this will become normal eventually.

    RCDs are a bit complex in design and so have a small risk of siezing up and failing to work, but they are a good invention. Thats why they have a test button. Wire fuses are great because they have no moving parts, but have other problems. Some electrical equipment has high leakage currents by design and so can cause false tripping of RCDs. They're not perfect but they do catch a different kind of fault to a mcb or fuse.
     
  10. ban-all-sheds

    ban-all-sheds New Member

    I`m only getting things together......replacing wires etc
    the connection to the main - CU will be done by a electrician.


    Then let your electrician supply and fit the CU with which he is most familiar/happy. Just as long as it isn't jomed with his non-split load malarkey - never heard such nonsense. And ask him to fit one that is bigger than you need now - people often add more circuits, they rarely remove them.
     
  11. snipper1

    snipper1 New Member

    Having contacted my Electrician he also speaks very highly of MK sentry CU`s.... and has assured me that he will purchase one for me.
    I also mentioned the 1mm cabling on lighting, and has also personally smacked me hand and told me to order 1.5mm
    so if anybody has a use for 100m 1mm cable i know where some is being sold cheep....very cheap.

    Thanks to all that has replied to my post it has been most helpful.
     
  12. jomed

    jomed New Member

    Just as long as it isn't jomed with his non-split load malarkey - never heard such nonsense. >

    I've had a sensible debate with Damocles on split load v. non-split load - shame that you just dismiss this as nonsense without any reasoned justification!

    My view is that a split load CU may not suit every situation and there are cases where protecting all the circuits with an RCD is sensible. I guess 'ban-all-sheds'customers would not be given the choice.
     
  13. supersparky

    supersparky New Member

    bas aint a sparks

    i dont beleve in non split load for one reason; rcd goes= no lights
    'so what about the risk of pokeing your fingers in the pendant' well its a good point but this can be combatted with the use of shilded pendant, making it impossible to touch the terminals

    jomed, i havent read what your points are but i have a feeling that may have been one?

    ss
     
  14. Damocles

    Damocles New Member

    Well i accept that designing fittings so that you cant stick your fingers into them by accident is a good idea, but I do think that sometimes people should be expected to learn a few things about life, like sticking your finger in a fire is a bad idea too.
     
  15. supersparky

    supersparky New Member

    so where is this discussion? or what were the points in it?
     
  16. jomed

    jomed New Member

    i dont beleve in non split load for one reason; rcd goes= no lights
    'so what about the risk of pokeing your fingers in the pendant' well its a good point but this can be combatted with the use of shilded pendant, making it impossible to touch the terminals

    jomed, i havent read what your points are but i have a feeling that may have been one?>

    To take lighting circuits for example, don't you think a bedroom wall light could pose the same risk as appliances plugged into power circuits and so both circuits should be RCD protected?
     
  17. jomed

    jomed New Member

    i dont beleve in non split load for one reason; rcd goes= no lights
    'so what about the risk of pokeing your fingers in the pendant' well its a good point but this can be combatted with the use of shilded pendant, making it impossible to touch the terminals

    jomed, i havent read what your points are but i have a feeling that may have been one?>

    To take lighting circuits for example, don't you think a bedroom wall light could pose the same risk as appliances plugged into power circuits and so both circuits should be RCD protected?
     
  18. supersparky

    supersparky New Member

    no, simply because you wont plug a applince other than a bulb into a light fitting
    i also beleve that loosing all lights because your rcd cuts would be a bigger probrability of indjury
    i beleve a properly installed wall light with a good earth would be sufficiant, for instance, you are unlikely to stick your finger right into the fitting without touching both terminals/ touching metal casing if aplicable, they should also make sure that the switch is off anyway, this can be acheved by making sure the switches are in the open position, or turning off at the breaker first, on 2 way switching the switches should both be in the same position which will mean the light power is off.

    ss
     
  19. jomed

    jomed New Member

    so where is this discussion? or what were the points in it? >

    See 'CU Questions' on page 2 of Electricians talk.
     
  20. jomed

    jomed New Member

    i beleve a properly installed wall light with a good
    earth would be sufficiant, for instance, you are
    unlikely to stick your finger right into the fitting

    I take your point but young children do like investigating and bulbs are really easy to unscrew.....?
     

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