new changes to fuse board material type

[mrloy99]

I recon for TT it will still need to be plastic enclosure but it will have to be housed in an enclosure lined with that asbestos type sheets(that aren't asbestos,forget the name of it) It shouldn't pose a vast problem as on many(public sector/housing association)jobs anyway as the builders have been lining the inside of the electric cupboard for a few years now,probably a building reg.

 

[the pict]

Again a piece of legislation that is completely ludicrous, a bad termination is a bad termination and containing it in a tin box is not a solution to poor practice and /or crap products,
Pict

 

[mrloy99]

For the life of me, i don't understand this thing about domestic TT and metal CU's... What's the problem with insulated and sheathed tails passing through a grommeted hole in a metal enclosure?? Something has to go drastically wrong for the live conductors to come into contact with the metal opening, or indeed within the enclosure.

as I understand it the reason is that the TT installation has to be RCD protected,and the incoming tails are not.....(before the rcd)..so if one of these live(neutral) tails were to touch metal enclosure...the service fuse may not operate.Possibility of crossed wires incoming is probably why it needs to be all poles switched.
I don't think that grommets are the issue,more likely the terminations coming loose and touching the metal enclosure and then again how effective is the earth from the earth spike,remember you don't have the luxury of an incoming earth from the supply company. The tails could get tugged by an unwitting householder trying to drag his hoover out of the lekky cupboard.and ZZapp possible dead guy

 

[Leesparkykent]

as I understand it the reason is that the TT installation has to be RCD protected,and the incoming tails are not.....(before the rcd)..so if one of these live(neutral) tails were to touch metal enclosure...the service fuse may not operate.Possibility of crossed wires incoming is probably why it needs to be all poles switched.
I don't think that grommets are the issue,more likely the terminations coming loose and touching the metal enclosure and then again how effective is the earth from the earth spike,remember you don't have the luxury of an incoming earth from the supply company. The tails could get tugged by an unwitting householder trying to drag his hoover out of the lekky cupboard.and ZZapp possible dead guy

Sorted!

 

[Des 56]

The guidance for TT metal clad cons units for just that scenario of having to Rcd the tails
It involves enhanced glanding of the entry hole and cable restraints for the tails then omit the Rcd

 

[davesparks]

as I understand it the reason is that the TT installation has to be RCD protected,and the incoming tails are not.....(before the rcd)..so if one of these live(neutral) tails were to touch metal enclosure...the service fuse may not operate.Possibility of crossed wires incoming is probably why it needs to be all poles switched.
I don't think that grommets are the issue,more likely the terminations coming loose and touching the metal enclosure and then again how effective is the earth from the earth spike,remember you don't have the luxury of an incoming earth from the supply company. The tails could get tugged by an unwitting householder trying to drag his hoover out of the lekky cupboard.and ZZapp possible dead guy

Then those tails have not been installed with adequate support or protection regardless of what the earthing system is if they are susceptible to such damage.