S.W.A. Armour Earthing.

Does plastic conduit provide insulation ... or is it there for mechanical protection?

Does the sheath of a cable provide insulation ... or is it there for mechanical protection?


I think we all agreed earlier in the thread, that if you can't touch the armour it was OK (inside sheath), but where you can, it should be either enclosed or insulated.


The situation still remains that, if you don't insulate the armour in the enclosure, it's not "finger-proof" from the perspective of accidental contact by a skilled or instructed person on opening the enclosure.


I'd argue that any "incident" that may occur with accidental contact with the armour under certain conditions is reasonably foreseeable, and is reasonably practicable to prevent.


As a designer under CDM risk assessment, the decision is, of course, yours.

• Long runs of cable down railway or highway infrastructure probably present a greater risk, and definitely should be addressed in the way I illustrated (or similar)

• If we had a situation where, for example, connection to PME was seen as a risk, then that risk must still be present for the electrician working in the enclosure, however small - I guess it's up to the designer to determine the likelihood?

Does plastic conduit provide insulation ... or is it there for mechanical protection?

Does the sheath of a cable provide insulation ... or is it there for mechanical protection?


I think we all agreed earlier in the thread, that if you can't touch the armour it was OK (inside sheath), but where you can, it should be either enclosed or insulated.


The situation still remains that, if you don't insulate the armour in the enclosure, it's not "finger-proof" from the perspective of accidental contact by a skilled or instructed person on opening the enclosure.


I'd argue that any "incident" that may occur with accidental contact with the armour under certain conditions is reasonably foreseeable, and is reasonably practicable to prevent.


As a designer under CDM risk assessment, the decision is, of course, yours.

• Long runs of cable down railway or highway infrastructure probably present a greater risk, and definitely should be addressed in the way I illustrated (or similar)

• If we had a situation where, for example, connection to PME was seen as a risk, then that risk must still be present for the electrician working in the enclosure, however small - I guess it's up to the designer to determine the likelihood?