I have a 4 core 2.5 cable, 3phase earth running out to an isolator.
The SWA has a CSA of 20mm but is only the equivalent of a 6.43mm
The regs say thew minimum CSA of a main protective bonding condutor should be no less than 10mm square.
Can I use the SWA as my main protective conductor.

I also have 3 seperate SWA cable running to the same isolator can I combine all 4 SWA and use it as my main protective bonding conductor. or do I need to run out a seperate earth cable.

Hi, could you explain a bit clearer what you are trying to achieve, ie: where you already have a 2.5mm core and presumably the armour of the swa currently connected as the c.p.c, what is the reason that you need sufficient csa to use these connections as a main protective bonding conductor - will you be connecting from this isolator to extraneous conductive parts?

Maca

Your equivalent 6.43mm2 is only applicable if used as a cpc not bonding conductor. The copper equivalent is approximately 2.5mm2

Regards

Jobbo

i can't see how you can use multiple cables to make up a main bonding CSA. there is the obvious and likely possibility that some of them might get removed or altered at some point in the future.

Gary

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Specialised Subject. The Bleedin Obvious. John Cleese

Safety label in accordance 514.13.1 ?

Maybe not -

OMS

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Failure is always an option

If the load is a motor on a VFD, then run a separate bonding conductor, as the SWA would be a screen, for the VFD noise in the cable, and the bonding conductor becomes the functional earth.

Best document for cabling a VFD is an ABB drive manual.

Regards

Derrick