Install as per manufactures instructions.
Tyco/Raychem insist on Rcd.
https://www.traceheatinguk.co.uk/Cache/Downloads/Installation-Manual-Self-regulating-cables.pdf
Tyco/Raychem insist on Rcd.
https://www.traceheatinguk.co.uk/Cache/Downloads/Installation-Manual-Self-regulating-cables.pdf