Can I use the sheath of the SWA as the CPC in this example?

[Dustydazzler]

I think originally 3c swa was really only meant for 3 phase machines etc

If you just required line and neutral you used 2c swa

I think once swa started being used more domestically it all changed and home electricians and DIYer s would use 3c because they could connect line neutral and earth using cores and not having to use the armour as an earth