Extraneous conductive or not ?

[equitum]

The roof supports/frame of a plastic keter style shed are not earthed/and not in contact to the ground and not part of the electrical installation. Therefore not an extraneous conductive part.

However if fitting luminaires, of which the casing is metal/conductive and earthed directly to this framework, should the luminaires be insulated from the metalwork to prevent it from becoming earthed ?

 

[EFLImpudence]

The roof supports/frame of a plastic keter style shed are not earthed/in contact to the ground and not part of the electrical installation. Therefore not an extraneous conductive part.

Please verify which if any parts are metal and confirm you mean not in contact with the ground

However if fitting luminaires, of which the casing is metal/conductive and earthed directly to this framework, should the luminaires be insulated from the metalwork to prevent it from becoming earthed ?

Assuming the framework is metal and not in contact with the ground then generally it would be better if the metal of the lights were not connected to it.

 

[equitum]

Thanks for reply. Correct - not in contact with the ground. Please expand - on what basis would it be better to not have the earthed casing of class 1 fittings connected to it ?

 

[RandomGrinch]

on what basis would it be better to not have the earthed casing of class 1 fittings connected to it ?

Think of birds sitting on an overhead line!

 

[EFLImpudence]

Everything would be better if it were not earthed.

It is just unfortunate that some appliances are made of metal which might become live in the event of a fault because they contain live wires.

 

[equitum]

Thinking about this further, the luminaires are wired in flex (L,N,CPC) The same metal frame work is used to support the flex. So in the event of damage to the cable it is possible the framework could become live (in much the same way as tray work) - so now becomes an exposed conductive part - which would normally be earthed wouldn’t it ?

 

[EFLImpudence]

Thinking about this further, the luminaires are wired in flex (L,N,CPC) The same metal frame work is used to support the flex. So in the event of damage to the cable it is possible the framework could become live (in much the same way as tray work) - so now becomes an exposed conductive part - which would normally be earthed wouldn’t it ?

It would - if that is what you have decided it is - but is that really the case?

I think it would be preferable not to run the flex in such a manner.