Main cut out fuse rating verification
- Thread starter boolie
- Start date
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No.
post a picture, is it a stuck on label.
The main label is put on when the things made, 100 is the max, round here they stick on a seperate label if they derate the fuse, but not always.
Not sure but i think its not very common to actually find a 100amp fuse actually fitted inside a 100 amp domestic carrier
The main label is put on when the things made, 100 is the max, round here they stick on a seperate label if they derate the fuse, but not always.
Not sure but i think its not very common to actually find a 100amp fuse actually fitted inside a 100 amp domestic carrier
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Calling the DNO in theory they can tell you, in practice often they can't, but then their expense to send out some one to check, however the question is why do you need to know?
When fitting a new consumer unit if not marked I would enter 100 amp even if really 60 amp, unless I know it is lower, I would work on the idea it was 100 amp and any isolator or RCD would need to either supply less than 60, 80 amp MCB's or be 100 amp rated.
With my own house clearly marked 60 amp, likely because the old Wylex fuse box isolator was rated 60 amp, if it ruptured likely the DNO would replace with a 100 amp.
If installing a high current machine you should be telling the DNO anyway, for example an EV charging point. So why do you need to know?
When fitting a new consumer unit if not marked I would enter 100 amp even if really 60 amp, unless I know it is lower, I would work on the idea it was 100 amp and any isolator or RCD would need to either supply less than 60, 80 amp MCB's or be 100 amp rated.
With my own house clearly marked 60 amp, likely because the old Wylex fuse box isolator was rated 60 amp, if it ruptured likely the DNO would replace with a 100 amp.
If installing a high current machine you should be telling the DNO anyway, for example an EV charging point. So why do you need to know?
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Indeed so. Mine certainly have extra labels on them to inicate the rating of the actual fuse which has been fitted. The OP's photos seems to show only the 'fuse holder rating', so doesn't really tell us what fuse has been fitted.
I believe that's true. In fact, knowing how much people like 'safety margins', I doubt that they would use fuse holders which seem to be invariably 'rated at' 100A if they were commonly putting 100A fuses into them.
Kind Regards, John
Possibly. However, for what it's worth, my daughter's house recently had a meter change and, despite a clear "60A fuse" label on the cutout, they installed new 25mm² tails.
Maybe some companies are 'thinking ahead' to EV chargers etc.?
Kind Regards, John
Someone doesn't know their Ls from their Ns.
Experiences vary. At my penultimate meter change, about 6 or so years ago, they changed all my tails - seemingly to 16mm² ones for each of the phases and 25mm² for the neutral. At a subsequent 'routine (non-'smart') meter change', about 3 years later (goodness knows why!), they seemingly changed the neutral one to 16mm² as well (although I didn't notice that for a long time)!
They also, at the last change, reduced the three phase fuses from 80A to 60A ("because that was plenty for me" - which is true) - although I'm not at all sure that the meter fitter (rather than the DNO) should really have done that!
Kind Regards, John
Mmm... seems odd for anyone to go to the effort and expense of replacing a large cable with a smaller one just because it could carry too much current. Still, I've given up trying to understand people.
They didn't do that - the tails had always been (looked like0 16mm² - I was just pointing out (in response to what you had said) that when they replaced tails quite recently (~6 years ago), I imagine because the existing one's weren't long enough for the new meter (they looked healthy enough), they replaced 16mm² ones with 16mm² ones (at least for the phase ones).
As for why, the next time, they changed the (seemingly) 25mm² neutral tail with a 16mm² one, that's anyone's guess - maybe it was just someone's idea of neatness/consistency!
Kind Regards, John
Sorry, I must have taken
to mean "they changed all my tails to 16mm² ones".
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