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Switch Fuse?

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  • 30-03-2015 7:30pm
    #1
    Tuco88
    Registered Users Posts: 1,051 ✭✭✭


    Hi Lads,

    Just a few questions on a domestic installation job.

    1)I recently purchased a domestic consumer unit, It's a Hagar model and noticed it had a 80amp Isolator instead of the usual Switch-Fuse. I am aware of the recent change to have a 63amp Mcb in the meter box to protect tales over 3m.

    In my case its over 10m so do I keep the Isolator or swap it out for the Switch Fuse? I know its not good discrimination to have a 63mcb in series with the 63amp Switch fuse.. Id sleep better with Switch fuse in place, I have seen Mcb's stick before.

    2)A Bathroom fan Isolator can it be over the door or must it be switch height? Its not a functional device so id say over the door but I have been told otherwise.

    Sorry for the silly questions in work manly in the Pharma industry.

    Thanks.


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    #2
    Tuco88
    Registered Users Posts: 1,051 ✭✭✭Tuco88


    Any opinions lads?


  • Options
    #3
    solargain
    Registered Users Posts: 330 ✭✭solargain


    No point in having 2 63A in series you loose discrimination. The switch on the board is fine , in this instance. There is still an 80 A HRC fuse backing it up at the meter.

    The bathroom fan isolator is down stream of the switch and can be located anywhere local to the fan.

    All of this is in the ETCI regs


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    #4
    Tuco88
    Registered Users Posts: 1,051 ✭✭✭Tuco88


    Does anyone know for sure if the Switch fuse is out? I was today that it is by an inspector,Not a very helpful one at that not sure he knows much,it's gone. There is a 63a MCB in the meter box as of 533.3.5 We removed the isolator in the cu and placed a 63amp switch fuse in place, I was always told it was fail safe better practice. For get about discrimination here. Anyone else agree?


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    #5
    Risteard81
    Registered Users Posts: 2,567 ✭✭✭Risteard81


    Although it is required to have the 63A MCB where the tails exceed 3m, unfortunately two IS EN 60898 MCBs in series will not provide discrimination/selectivity. A fault current anywhere in the installation is liable to cause operation of the Main Protective Device.

    Fortunately full discrimination does not tend to be very critical in a domestic dwelling however.


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    #6
    Risteard81
    Registered Users Posts: 2,567 ✭✭✭Risteard81


    Although it is required to have the 63A MCB where the tails exceed 3m, unfortunately two IS EN 60898 MCBs in series will not provide discrimination/selectivity. A fault current anywhere in the installation is liable to cause operation of the Main Protective Device.

    Fortunately full discrimination does not tend to be very critical in a domestic dwelling however.


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    #7
    Tuco88
    Registered Users Posts: 1,051 ✭✭✭Tuco88


    Farewell to the 63a switch fuse so.


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