Meter Tails in cavity wall

[Rampantchilli]

If its says 100a on the carrier then you must assume that's what's there, as you can't take the carrier apart to check without cutting the seals,
"we'll Mr assessor, I didn't want to change the tails so I cut the seals and checked the size of the fuse inside, and how dare they put an 80a in, I've put a note on my certificate and written to Western Power demanding an apology" lol

as for your earth, cut the existing wire and use the length from cut-out to CU to terminate into your new MET , as you can't access the connections for the DNO earth connection, as its in the cut-out and you need to cut the seals to access.

and can we no longer call the meter box a meter box?, has that now been harmonised into an external cabinet, cut the new hole where YOU need it, apply your fishing skills and when finished reseal the hole with fire stop, but I question if they need to be sealed as they are not particularly sealed when fitted.

 

[Darkwood]

100amp on the service carrier is the max' rating fuse it could carry, it is not an indication of the fuse within- this should be done by enquiry but as we all know this takes forever so assume its 100amp and upgrade to 25mm tails.

I see this carrier rating getting confused all the time with what fuse size should be fitted... many a control panel with oversized fuses in the carriers because the on-site 'maintenance' dosn't understand the basics.

 

[Midwest]

Yes sorry about that, external cabinet it is, can't think where I might have picked up such bad terminology from.........Meterboxs Direct Online Shop | Electrical Meter Box Doors & National Grid: Domestic meter box spares and repairs further help and guidance etc etc, whereas external cabinet........Cabinet Secretary for Culture and External Affairs - Wikipedia, the free encyclopedia

Anyhows, appreciate all the advice. I know that replacing tails is the subject of countless posts. I will need to change these (insufficient length) and I will install 25mm or even 35mm, to take into account thermal insulation (not currently installed)! Therefore I will have to replace the current 10mm EC.

From what I have been able to research, installation of cables in cavity walls is undesirable as applicable requirements of BS7671 cannot be met: damage to cable during installation, cable lacking support, mutual damage to cables from thermal insulation, cables in thermal insulation (reducing ccc), unknown presence of flora or forna & bridging of the cavity by moisture (Building Regs). Apparently though (I can't find the actual section), NHBC Sec. 8.1, section 2 standards state 'no cables, other than meter tails are to be installed in cavities.

So therefore my thoughts are that as long as I can comply with BS 7671, install tails in cavity, protecting them in flexible conduit or similar (protection against damage, mutual damage, strain etc it should be okay. I've checked a few DNO sites, and most demonstrate the installation of tails in the cavity, only one specifically stated they cannot. What da ya think?

 

[Darkwood]

Its all down to interpretation you have just listed many area's where cavity installed cables would be a bad idea direct, the environmental sheath (outer) provides minimal mechanical protection from falling debris which often falls from the full height of the cavity from loose debris at the top, i have also encountered this damage as well as damaged cables done on install.... if you can reduce the risk of things falling on cable then sorted ie... remove a few bricks and create a ceiling of expanding foam above the cable run..... but here's the thing many dont bother most just run it anyway but it dosn't mean its right to do so.

 

[staggie65]

If the cavity has any metalwork in it it should be protected by RCD (other than screws/nails)

 

[Darkwood]

If the cavity has any metalwork in it it should be protected by RCD (other than screws/nails)

Where do you get this from????

Most cavities have metal bridge ties to hold the outer wall to inner but having said this a RCD wouldn't be required because of this- where do you get that from?,,,, the cables would be >50mm deep so not needing RCD for that reason either.

 

[Geoffsd]

Is this thread a job creation scheme?

 

[Doomed]

Sorry, but if you are not going to cut the DNO seal to achieve safe isolation then how are you going to change the tails? Unless you are cutting the seal on the meter and disconnecting from the meter live.

 

[Rampantchilli]

Sorry, but if you are not going to cut the DNO seal to achieve safe isolation then how are you going to change the tails? Unless you are cutting the seal on the meter and disconnecting from the meter live.

contractors switch?

 

[Midwest]

Sorry, but if you are not going to cut the DNO seal to achieve safe isolation then how are you going to change the tails? Unless you are cutting the seal on the meter and disconnecting from the meter live.

Not me, I would pull the fuse, off load of course.

 

[Darkwood]

This is indeed the catch 22 of the whole thread!

 

[Midwest]

Not this one but others agreed!