Meter Tails Over 6 Meters In Length

[sjwkmje]

Hi All,

This is a new one on me but I have been asked to fit a consumer unit upstairs in a house and the tails will need to run just over 6 meters to the location where the meter is. Its a TN-C-S supply. Its going to be a split tails job with the new consumer unit supplying dedicated server and network equipment.

I remember a few years back it was a requirement to fit an isoaltor with intergral fuse (usally 80a hrc) to protect the tails if anything went wrong. I have not heard anything since and regually go to installs and see 4 meter tails that dont have an isoaltor with intergral fuse and this is in new house installs where the TN-C-S supply comes in at the side of a garage and goes accross the garage roof into the house, where the garage is joined to the house.

Nothing in the 16th edition about this.

Any one know if I can run tails this lenght without an isolator or do I need to find an isolator.

The cables will be mechnically protected using capping in the wall chase up into the floor upstairs then accross with corercley placed holes drilled in the joists. Then it comes up in some large ducting to a low down consumer unit in dedicated location for the network equipment. The cable will be fully protected against accidental cuts etc.

Adam Horden

 

[ricicle]

A lot of DNOs will only allow mains tails to be 3m or less.Any longer and you will have to fit an appropriate switch-fuse.

 

[Adam_151]

It all depends on how long a length of tails the DNO allow their fuse to protect, its common for them to limit it to 3m, but this isnt true of them all, ask yours what they allow.

if you want to go over what the DNO allow, you can fit a switchfuse and feed a submain from it to a CU

 

[sjwkmje]

Can any one recomend a switch fuse that can fit inside a standard white meter box. The ones I have seen before are Hager 100 Amp TP and N Switch Fuse HRC but they are huge!

Thanks for the advice, for saftey I will fit a switch fuse.

Adam

 

[partpdoctor]

hi
we fit a merlin 80A dp breaker in a small metal enclosure
the 80A unit is 3 standard modules in size, not two, so our enclosures have "half a blank" fitted each side-if you know what i mean!
don't know the catalogue numbers, but this may lead you to it

 

[sjwkmje]

Hi,

Can I fit a 100A isoalator and a 80A Double Pole MCB next to it to prtect the cable or does it have to be a fuse?

I would still use tails out of the 80A Double Pole MCB to th new CU.

Adam

 

[IJWS15]

I am not far from you and our meter tails are around 8-9m long. From external meter box through the garage wall, across the trusses of the double garage and down the wall to the CU.

Nothing in the box apart from the Main fuse!

House is around 6 years old and was built like that.

 

[Albert]

To be on the safe side I would put in a fused isolator. It is always useful for future interventions.
you can find these fused isolators everywhere, starting with B&Q and ending with any of the electrical wholesalers.

 

[Taylortwocities]

Can any one recomend a switch fuse that can fit inside a standard white meter box.
Adam

You cant put it there. The box is reserved for the DNO's equipment.

 

[sjwkmje]

Can any one recomend a switch fuse that can fit inside a standard white meter box.
Adam

You cant put it there. The box is reserved for the DNO's equipment.

In the last 5 years or so I have seen countless consumer units, split tales and consumer units for garage supplies / showers etc in those cuboards. Spoke to an ex MEB engineer and he agrees that the switch isolators should be in there. Any ideas when this came in?

Adam

 

[Steve]

Can any one recomend a switch fuse that can fit inside a standard white meter box.
Adam

You cant put it there. The box is reserved for the DNO's equipment.

In the last 5 years or so I have seen countless consumer units, split tales and consumer units for garage supplies / showers etc in those cuboards. Spoke to an ex MEB engineer and he agrees that the switch isolators should be in there. Any ideas when this came in?

Adam

Your not supposed to put it there. Many do. And i'd rather hear a FULL TALE than a SPLIT TALE.

 

[Taylortwocities]

When you do a split tale you have to come back a week later to finish it off!

 

[Steve]

When you do a split tale you have to come back a week later to finish it off!

Many DIYers wanting help on this forum already do this!!!

 

[sjwkmje]

When you do a split tale you have to come back a week later to finish it off!

Many DIYers wanting help on this forum already do this!!!

Ah I am not a DIYer , trained sparky about 3 years ago, ending up doing a BTEC ONC in electrical and electronic engineering, spent 4 years working in a hospital (maintatence) , then decided to go back to uni. Been out the game for big installs for about a year, been doing plenty of little installs over that time.

Thanks for all the advice,

Adam