16mm t+e sub main

[Mike Watters]

periodic report says it's inadequate. was installed 10 years ago. 60 amp rewireable fuse protects the cable. the main supplies a small bed sit with 1 x lighting circuit, 1 x 32 amp radial socket circuit and 1 x cooker circuit that has a 3kw cooker. a new wylex consumer united was fitted 2 years ago. why would it be ok 2 years ago and not now.

 

[Rockingit]

I put a 16mm T&E into a bungalow last week to facilitate a board relocation - original 16mm tails now go to a DP iso, then run to the new board via 16mm TE clipped to the loft joists. I just ran a 10mm earth alongside it from a new MET, so effectively giving it a 16mm earth as well. Cut-out is only a 60A (1 bed bungalow) so I have no problem with it all being 16mm not 25mm.

 

[jase]

maybe they are getting things mixed up cos it is supplying a board and they think all tails have to be 25mm with a 16mm earth???

 

[tony mc]

If its a Periodic or EICR it should explain what is inadequate and a suitable code attached to that observation.

What has been documented re the above?

What is the earthing arrangement for the premises?

 

[GLENNSPARK]

If its a Periodic or EICR it should explain what is inadequate and a suitable code attached to that observation.

What has been documented re the above?

What is the earthing arrangement for the premises?

and while its all about "its this....its that"....the voice of sense comes forth......is it a "2"...or what?.....

 

[Mike Watters]

the report said code 1. disconnection times not met for fuse type. it,s a 3 phase tnc s, each phase supplying 3 studio flats

 

[telectrix]

i would not consider disconnection times not being met as a code 1 ( immediate danger ). question that comes to mind is what disconnection time was he looking for?

 

[brman]

Shouldn't there be a Zs/Ipf on the PIR/EICR? Wouldn't that be enough to determine the disconnect time?
I might be getting a bit ahead of myself as I have only just started my 2395 and I am not clear whether the PIR was for the whole installation or just the sub board but I'd have though there should be enough info recorded to work out what the problem is.

 

[tony mc]

As a C1 has been issued what has been done to take that immediate danger away and make the premises SAFE!.

A bit more info is required as this type of vauge report putting fear into people not good practice.

I don't like to guess but I would say the issue here is the 6mm earth on a TNC-S system which should be a minimum of 10mm as that is the minimum csa for the bonding conductors.

If you have the ZE the adiabatic can be worked out but due to the PME system in place table 54.8 is the reference.


On the EICR item no's 3.4 and 3.6 should have a code attached if that is the case.

 

[Mike Watters]

ok good thinking i will check the test results. thanks.i will let u know my finding.

 

[Guest111]

Doncaster cables website has a useful cable calculator for swa on their website if it helps anyone.

 

[Knobhead]

Cable Size Calculator :: Doncaster Cables - Manufacturers and Suppliers of Cables Meeting British and European Specifications

 

[telectrix]

just tried that doncaster calc. i put in 60A , 20m run, 5% VD. it came back with 6mm!!!