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Incoming supply cable and 16mm/25mm tails questions

Jimi

Hi, I've rewired a property, 100A main fuse, 2 electric showers plus everything else so maximum demand is potentially over 100A in theory. I added a main isolator and used 25mm tails to the CU. The distributors tails look slightly smaller so I'm assuming 16mm unless the sheath is thinner. 

Does everyone report if there are 16mm tails on a 100A main fuse? Why did the distributor not put 25mm tails in when they put a 100A fuse in? Does anyone know what size the conductors of the actual incoming cable are? If less that 16mm does that mean digging the street / house up to replace it with 25mm? 

Thanks!

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  • 0

    Is it definitely a 100A fuse? The label on the carrier usually refers to the carrier rating - and it's very common practice to install a lower rated fuse inside (my local DNO has standardised on 80A and takes a lot of persuading to go higher these days).

    Also the DNO might consider that their and the meter's terminals are good to say 90 degrees rather than the 70 degrees that BS 7671 usually assumes -  in which case 16mm2 can be good to over 100A.

       - Andy.

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  • 0

    Is it definitely a 100A fuse? The label on the carrier usually refers to the carrier rating - and it's very common practice to install a lower rated fuse inside (my local DNO has standardised on 80A and takes a lot of persuading to go higher these days).

    Also the DNO might consider that their and the meter's terminals are good to say 90 degrees rather than the 70 degrees that BS 7671 usually assumes -  in which case 16mm2 can be good to over 100A.

       - Andy.

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