never seen before building earthed via trunking

[bonjovi]

hello all in my considerable yrs ive never come across a building earthed via trunking all circuits lights power earth taken back to nearest trunking and terminated no earths at board even main earths for 5x different panels back to trunking is this legal in todays regs ?

 

[Pete999]

Any test carried out ZS, etc

 

[Andy78]

The wiring regs aren't a legal requirement. Using containment as a CPC is permitted by the wiring regs. The usual rules for protective conductors apply with regards to thermal constraints and sizing etc. Of course the integrity and condition of the containment and all associated couplings and joints is essential.

 

[bonjovi]

yes all seem fine just never come across it before

 

[davesparks]

It is not legal in the regs, nothing is legal in the regs, the regs have no legal status.

It can comply with regulations if the requirements of the regulations are met, if they are not then it does not comply.

Use the adiabatic equation to calculate the required CSA of a steel CPC and then compare that to the actual CPC, this will tell you whether it is the right size or not.

Then measure the Zs using a high current test and this will tell you whether that complies or not and give an indication that all connections are sound.

ideally you would use a ductor type high current milliohm meter to confirm the soundness of the connections but they aren't so commonly available to us humble electricians any more


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[westward10]

Not common now but I have done this back in the 80s. We installed separate cpcs through the conduits to socket outlets etc and bolted them to the trunking. Don't know why I can only assume that as the trunking had straps across each joint but the conduit connections did not it ensured good continuity. Can't beat using containment as a cpc.

 

[Paul P]

Not common now but I have done this back in the 80s. We installed separate cpcs through the conduits to socket outlets etc and bolted them to the trunking. Don't know why I can only assume that as the trunking had straps across each joint but the conduit connections did not it ensured good continuity. Can't beat using containment as a cpc.

I remember doing this in the 80s as well we had copper links to put over the screws on the couplers.