meter tails and cut out fuse

[bonn1ett]

Hi people,
I recently installed a cooker circuit in a property. The CU has 16mm meter tails supplying it with a 60A cut out fuse.
I have read various opinions on this but:

• Should the meter tails be changed to 25mm even on a 60A fuse - in which case the fuse is not protecting the tails?
• or is it a case of leaving it as it is with the existing 16mm tails?

any advice is most appreciated!

 

[KAS1]

What do you mean "in which case the fuse is not protecting the tails?"

Read more: http://www.electriciansforums.net/e...3-meter-tails-cut-out-fuse.html#ixzz2HxxLC5Mm

Hi people,
I recently installed a cooker circuit in a property. The CU has 16mm meter tails supplying it with a 60A cut out fuse.
I have read various opinions on this but:

• Should the meter tails be changed to 25mm even on a 60A fuse - in which case the fuse is not protecting the tails?
• or is it a case of leaving it as it is with the existing 16mm tails?

any advice is most appreciated!

 

[bonn1ett]

as i understand it - 16mm cable has a current carrying capacity of 87A, so 60A fuse is adequate
25mm cable has a current carrying capacity of 114A therefore 60A fuse is no longer adequate and would ideally need 100A fuse

 

[KAS1]

I don't think you get the gist of cable/fuse rating etc

 

[HappyHippyDad]

Hi Bonn,

You'd really need to work out your max demand to see if the tails need increasing to 25mm. As for the fuse size, a 60A fuse is still going to protect 25mm tails, but it might blow if your max demand is too great, I think you've got things the wrong way around a bit! The OSG suggests all tails should be 25mm, but it just a guide and I cant see anything in the regs about tails HAVING to be 25mm.

 

[bonn1ett]

sorry, not making myself clear,
i understand fuse ratings ok.
I understand that having a 60A fuse with 25mm tails would still be ok but ideally if 16mm tails are present with a 60A fuse then would you change the tails to 25mm anyway?

 

[KAS1]

Is this for real once again more stupid questions lol

 

[HappyHippyDad]

I would only upgrade to 25mm tails if after working out the max demand of the household (after diversity) it looked like 16mm tails would not be able to cope with the max demand.

 

[HappyHippyDad]

Is this for real once again more stupid questions lol

Calm down chap, I'm sure you asked some dubious questions once upon a time before you became so wise. Its quite a common question as the OSG does say tails should be 25mm.

 

[bonn1ett]

Thanks happyhippydad!
that's my point (although made very badly i know!). I have read on other threads various opinions on this, some say they would change the tails whatever the fuse rating, others have said there is no need to change the tails if the fuse is 60A but if 100A fuse then obviously change tails to 25mm. All depends on the load as you've mentioned.

 

[KAS1]

Yeah sorry I've had a bad day lol

- - - Updated - - -

The wife's run off this morning and taken the dog

 

[telectrix]

them tails ain't broke so don't fix 'em. if and when the installation requires a larger rating ( 100A fuse ) then upgrade the tails then. if the demand exceeds the capacity of the tails, the fuse will blow to protect them.

 

[telectrix]

Yeah sorry I've had a bad day lol

- - - Updated - - -

The wife's run off this morning and taken the dog

local rag advert then,

" missing since this morning, wife and dog. reward offered for safe return of dog"

 

[Octopus]

Hi people,
I recently installed a cooker circuit in a property. The CU has 16mm meter tails supplying it with a 60A cut out fuse.
I have read various opinions on this but:

• Should the meter tails be changed to 25mm even on a 60A fuse - in which case the fuse is not protecting the tails?
• or is it a case of leaving it as it is with the existing 16mm tails?

any advice is most appreciated!

Unless the existing tails are damaged I would leave them well alone.

 

[Deleted member 26818]

Something you should also consider, is that the distributor's fuse is not there to protect your tails.
It's there to protect the distributors equipment.
The fact that it would also protect your tails is happenstance.

 

[daimack]

'Happenstance' is a cracking word Spin, (never heard it before) I'm gonna see if I can use that a few times this week