Some suppliers send in the clowns to pull a fuse and don't put the fuse size on the it when changing the meter.
I have actually never come across a melted 10mm tail and still occasionally come across 6mm tails.
Yes I agree however it goes against the regs by using 16mm tails on 80A/100A fuse
interesting. so if the fuse is, as you say, to protect the DNO's cable etc., then the tails are not, themselved protected. only downstream in the CU, and indirectly by the actual max. load that may be relevant at any one time. therefore, using 25mm tails just because the DNO fuse is 100A is not justifiable. tin hat on by a guy who regularly fits 16mm tails.
From a quick look most places seem to use the same table in their literature, even the cable makers - though the one in the OSG seems to suggest it's more for Twin and Earth, not singles (with the 2 cables reference), Though if they are run cable tied together that probably has no effect anyway.
Is there a good reason why they don't give ratings for 16mm for Reference Method F in table 4D1A in BBB or F4(i) in OSG? Is 16mm single core not approved for Ref Method F installation or something?
that's clipped direct, method C. most CU tails are method F , free air.
Agreed on overkill comment. On the positive side there is no question that UK consumers are absolutely futureproofed with a 25mm supply. You do wonder at times though about cable current ratings in general when a 6mm is deemed adequate for a 40 amp mcb (all other factors permitting) but a 25 mm is required for an 80 amp fuse.
Nothing wrong with 16mm tails clipped direct on a 80 amp fuse.
That's good to know. I was under the impression that 25mm was your standard DNO supply in UK. Am I correct in assuming that the 25mm is required for a 100 amp supply?
New supplies like new build housing up my way , the dno stipulate 25mm tails and a 16mm earthing conductor with a 100 amp main fuse.
what about the cost in arthritis in the joints from bending and threading 25mm into a poxy CU with ahrdly any room ?
good on you Tel , my dad managed to keep working till he was about the same age but unfortunately suffered a mini stroke which messed up his right hand which ment he literally couldn’t hold anything without dropping it...
Yes you’re right and I’m constantly coding C3 for undersized meter tails. Just out of curiosity what do you code 6mm twin and earth with 10/15 mtr run to shower with power consumption of 9kw with thermal effects at pullcord? (Melted)
