16mm T&E to Consumer Unit

[hogey]

Afternoon everyone, I've just been to a neighbours house who has just her home completely done up as the foundations are shot. The house has been rewired and in doing so the consumer unit has been moved to one side of the house (the main fuse is outside on the other side of house). I've gone to swap a light fitting over for her and have noticed the elec contractor who's rewired it has used 16mm t&e supply. The cable is buried within the wall so not sure what protection they've used, i might dig out some of the plaster to see. The main fuse is an 80A (the seal has been cut off the fuse carrier so i checked). There are 1 x 10mm for shower, 1 x 10mm for cooker, 1 x 10mm for hob, 3 x ring circuits, 1 x radial and 3 x lighting circuits. The job must have been signed off already and I haven't done any cable calcs yet but it just doesn't sit right with me. Has anyone came across this before? Opinions? Thanks in advance.

Ste

 

[westward10]

How far does the cable run, how is it installed, has it been given circuit protection, where are the main protective bonds connected.

 

[Octopus]

When was it rewired?

 

[hogey]

It has been rewired within the last 6 months. The cable run must be 15m give or take, bonding comes from the main earth block at meter cupboard, no RCD on the 16mm T&E though (sorry was meant to say that), it's wired into a separate DP iso, i think 100A but will double check.

 

[onions1066]

Have they run a separate earth?

 

[westward10]

So have they provided circuit protection or are they relying on the service head fuse.

 

[westward10]

Have they run a separate earth?

Won't need one.

 

[onions1066]

Won't need one.

If it's come straight from the head on a tncs? Why is that

 

[westward10]

If it's come straight from the head on a tncs? Why is that

I am assuming circuit protection has been provided though that is not clear and main protective bonds are not at the CU.

 

[Octopus]

Need more info

 

[Midwest]

A quick referral to table 4D5, suggests the best ccc for 16mm tw&e is 85a (clipped direct). So with 15m negotiating through the house, can't see how its ever going to suffice? And as it buried in a wall, chances are without earthed steel plate capping, its going to need additional protection

Seen it may a time mind.

 

[7029 dave]

I have connected up new builds weeks ago, subs still being run in 16mm t&e.?

 

[Risteard]

How is the T&E connected at the origin? Because the way I'm picturing it there will be non-sheathed conductors outside of any enclosure or containment at that point.

 

[Ian1981]

How is the T&E connected at the origin? Because the way I'm picturing it there will be non-sheathed conductors outside of any enclosure or containment at that point.

Probably used the old favourite method of tape

 

[westward10]

Looks like we aren't going to find out.

 

[7029 dave]

Probably used the old favourite method of tape

or a switch fuse, with one of them fancy covers.

 

[hogey]

Hi Guys, sorry haven't had chance to reply... Yes they have taken a separate 16mm earth from main earth block to the C.U. The 16mm T&E goes from a 100A iso just past the meter to the C.U. inside the house, it's not a great job tbh... I'll upload a pic. Point still remains that IMHO 16mm T&E isn't fit for purpose in this instance. I don't really wanna get involved as haven't done any work there and its a ballache to rectify but i guess it's my duty...

 

[hogey]

 

[westward10]

That is a proper lash up. No circuit protection, cpc incorrectly sleeved and conductor insulation exposed at the switch.

 

[Wilko]

Probably used the old favourite method of tape

Winner !