building site compound electrical work

[lucus]

hi all
today i was working on a site compound for a major uk builder david wilson homes, i have been told by my site supervisor that all compound instalations need to have a earth spike even when there is a tncs supply availabe with a earth is this correct?
regards

 

[GT1]

hehe.... i should ask which reference number from the regs book he is quoting..!!

 

[bugsy]

DNO will not normally install PME supply to building sites are you sure it's PME

 

[Guest123]

TN-C-S should not be used on a building site.

Section 704 of the regs refers, also ESQCR and HSE.

Site buildings can use the system i.e offices, canteens, drying rooms etc but, not temp supplies to plant & equipment.

 

[lucus]

so i suppose the silo is the problem then with using a tncs system thanks everyone.

 

[lucus]

does anyone know the reason for this just so i can pass the problem on
regards

 

[Guest123]

It's all to do with the dangers that exist should the neutral conductor in a PME system go open circuit, and magnitude of the resulting currents that may be present in the earthing conductors and exposed steelwork/services. Also being outside an equipotential zone and impossible to run seperate 10mm bonding conductors to each and every extraneous conductive part thus creating a dangerous PD. Wholly unsafe particularly in area's defined as special locations in BS 7671, building sites are one of those locations.

 

[Bromd123]

It's all to do with the dangers that exist should the neutral conductor in a PME system go open circuit, and magnitude of the resulting currents that may be present in the earthing conductors and exposed steelwork/services. Also being outside an equipotential zone and impossible to run seperate 10mm bonding conductors to each and every extraneous conductive part thus creating a dangerous PD. Wholly unsafe particularly in area's defined as special locations in BS 7671, building sites are one of those locations.

so just for my knowledge what system would be used? TN-S? or TT they are the only ones that would make sense to me given what you have said

 

[bugsy]

Tt ( spiked)