upgrade meter tails, or downgrade main incoming fuse??

[martinsayer81]

hi guys

hoping you could give me your thoughts,

i am pricing for a consumer unit change, its an old fuseboard with re-wireables.
it has 16mm meter tails, but it has a fairly new looking 100A main fuse.

its a small-ish house..... 2 ring mains, 2 lighting radials, a couple of sockets in the garage, and an immersion heater radial,

i was wondering whether or not i could just down-grade the main fuse to a 60A and keep the existing 16mm tails( no damage, or signs of overheating or burning)
or whether i have to leave the fuse at 100A and fit 25mm tails?

there's no electric shower or oven,

i would appreciate your advice

many thanks

 

[Octopus]

Are you sure its a 100A fuse in the holder.

I'd say leave the tails as is - but that's just my opinion

Tin hat on.

 

[telectrix]

as above^^^ it may say 100A on the outside, but be a 60A fuse on the inside. just leave the 16mm tails in, and the fuse is not your responsibility.

 

[MDJ]

Tin hat on.

:helmet: :44:

 

[jaydee81]

when you say 100 amp fuse do you mean dno supply fuse?

 

[Guest55]

the only way to know for sure is for your hand to slip onto the seal whilst holding snips...........

 

[SYKRAPS]

As #2 & #3 the 16mm tails were probably installed by the DNO along with the fuse, I would be more concerned that the earthing and bonding was correct for the supply characteristics

 

[martinsayer81]

its the dno 100A fuse,
at the moment i am just going on the sticker on the outside, it was late in the evening when i looked at the job, and couldnt pull the fuse to check,

wouldnt it be against the regs to leave the 16mm tails with a 100A fuse?

i just dont want to get any come backs

 

[Octopus]

its the dno 100A fuse,
at the moment i am just going on the sticker on the outside, it was late in the evening when i looked at the job, and couldnt pull the fuse to check,

wouldnt it be against the regs to leave the 16mm tails with a 100A fuse?

i just dont want to get any come backs

The OSG pictures assume you are working on a new build....

Do they have 3 electric showers, multiple cookers, a canabis factory in the loft..... The usage for a house is unlikely to rise about 35 amps so I'd leave them welll alone.

 

[143del]

Hold onto your snips martin,
The requirement for 25mm tails are part of the PME supply regulations so if the supply is PME there is no getting away from that

 

[jaydee81]

bet its only 16mm tails from dno cut out to meter anyway

 

[dim_bulb]

Is it a major hassle to upgrade? If not price it in you can get a 2 meter tail pack for 15 - 20 quid

 

[martinsayer81]

The OSG pictures assume you are working on a new build....

Do they have 3 electric showers, multiple cookers, a canabis factory in the loft..... The usage for a house is unlikely to rise about 35 amps so I'd leave them welll alone.

so, basically, if it does turn out to be a 100A fuse in the holder, it would still be ok to leave the 16mm tails due to a low demand?

 

[martinsayer81]

Is it a major hassle to upgrade? If not price it in you can get a 2 meter tail pack for 15 - 20 quid

is there any likelyhood of the meter breaking on me when i open it up to change the tails??

 

[martinsayer81]

its a tns supply, the only upgrade to the earthing i have to do is the main earth, all the main earth and earth bonding at the moment is 10mm