pir code for undersizes water bond

[telectrix]

agreed. but if clipped onto pipework with a rusty croc clip, i might go as far as a C1.

 

[Farmelectrics]

code 3 for me

 

[oldtimer]

Me thinks there has to be a bit flexability here and they realise this so say you go to a 25 yo installation in a flat the DNO fuse is 60A it is a TNS with 6mm to the water and gas and the customer wants a new CU fine but you aint going to rip the flat up to put 10mm in and when I moved into my house there was a bit of stranded 1.5 unsheathed wrapped around the main stop cock so me thinks we need to get real here as I think 10mm is fine for a 100A supply with 25mm tails.

 

[Engineer54]

25mm tails and a 16mm earth for a service supply of 60A?? Bit of an overkill to say the least!! ...lol!!!

 

[telectrix]

considering that i've had 16mm tails running at 95A for an hour and just managing to reach 40deg.C.

 

[topquark]

The discussion was about the adequacy of the 6mm bonding on TNC-S! I think you've just made my point for me Tel!

 

[oldtimer]

25mm tails and a 16mm earth for a service supply of 60A?? Bit of an overkill to say the least!! ...lol!!!

Yep seems to be urban myth that the tails must be 25mm and the earth 16mm but for a flat with a 60A fuse then I would say 16mm tails 10mm earth and 6mm water/gas remember I have seen jobs lost because the customer wanted a new CU but did not want to upgrade the earth I think they call this common sense and why is it all of a sudden a safety problem when older installations have either no earth on the gas water and are borrowing one from the guy upstairs (work it out) or the earth is a 2.5-6.0

 

[telectrix]

amazing we never had loads of deaths under 13th. 14th , 15th editions. we didn't have the digital test equipment to read to 0.01ohms, >299Mohms. no RCDs, very rare to see MCBs, yet the human race survived. wonder how.........

 

[topquark]

Because power requirements were not as large and the scope for electrical failures much less likely, and yes the systems WERE adequate at the time they were installed. We did still have the 10mm minimum size main bonding requirement for TNC-S in the 16th though, hmmm I wonder why?

 

[telectrix]

because when the 16th came out, we had test gear that could measure an EFLI of less than an ohm, accurately, so then the IEE as was could come up with some fancy new regs.

 

[Guest55]

.............. yet the human race survived. wonder how.........

Stiff upper lip and cups of tea.
We were sturdyier folk back then lol.

 

[Snapester]

I have just done CU upgrade in a flat, 16mm & 6 earth with
6mm bonding. I feel 6mm is adequate for the installation even thought he main earthing system is TNCS. There is no damage or signs of overheating on earth conductors and disconnection times are good. Using ESC guidelines I've left 6mm in.