Earthing System Advice

[sajeel]

Hi
Saw a mates job the other day where the supply is three phase, however there was two earthing system at head there was tn c s and tn s. So there was separate earth clamped on supply wire to main earth terminal and a additional earth wire run which was connected to neutral of supply ?
Didn't think this is normal practice although dno have recently been to replace fuse ?
Then consumer was wired one earth in earth terminal and the other earth in neutral ?

 

[HandySparks]

Maybe originally TN-S, now converted to TN-C-S. Sheath still needs bonding.

 

[westward10]

As above, TN-S earth may have gone AWOL and dno just linked out to the neutral.

 

[sajeel]

thanks for replies, both the posts make sense, so if tn-c-s was upgraded then there would be two earth wires in terminal of cu ? or both fed to a met and then one wire fed to cu ?

 

[HandySparks]

thanks for replies, both the posts make sense, so if tn-c-s was upgraded then there would be two earth wires in terminal of cu ? or both fed to a met and then one wire fed to cu ?

I'd expect a MET near the incoming cable termination in this case.

 

[Ed Evans]

Hi
Saw a mates job the other day where the supply is three phase, however there was two earthing system at head there was tn c s and tn s. So there was separate earth clamped on supply wire to main earth terminal and a additional earth wire run which was connected to neutral of supply ?
Didn't think this is normal practice although dno have recently been to replace fuse ?
Then consumer was wired one earth in earth terminal and the other earth in neutral ?

Possibly hi Z so belt and braces!!!

 

[PEG]

I would have expected a DNO notice,at the head,to give some details....not always done,but that is taking it,that the supplier did the mod

 

[ipf]

Possibly hi Z so belt and braces!!!

Wonder if his pants have fallen down, yet?...…2016