ADS

If a little baby crawls over and grabs hold of a nice shiny radiator valve that has become and remained hazardous live because you have told everyone there is no need to earth radiators,

But how did the radiator get to be hazardous live in the first place? Any hazardous live conductors should not only have basic insulation but additionally be surrouned either by a second layer of insulation or equivalent (e.g. Class II equipment or insulating sheath of a cable) or deliberately earthed electrical metalwork to trigger ADS - those are the barriers that are intended to reduce the risk of shocks, not bits of random plumbing whose resistance and reliability we can't control. If someone has installed a cable that such that both the sheath and insulation can melt and make a pipe live then that's just bad workmanship - and the regs prohibit that directly.

Even the 18th Edition says earth heating systems,

Read it again - especially the bit about extraneous-conductive-parts (and the definition of an extraneous-conductive-part in Part 2 of the regs). Its also says bond, rather than earth - which might give you a clue about it's intended role (which isn't to trigger ADS).


   - Andy.

If a little baby crawls over and grabs hold of a nice shiny radiator valve that has become and remained hazardous live because you have told everyone there is no need to earth radiators,

But how did the radiator get to be hazardous live in the first place? Any hazardous live conductors should not only have basic insulation but additionally be surrouned either by a second layer of insulation or equivalent (e.g. Class II equipment or insulating sheath of a cable) or deliberately earthed electrical metalwork to trigger ADS - those are the barriers that are intended to reduce the risk of shocks, not bits of random plumbing whose resistance and reliability we can't control. If someone has installed a cable that such that both the sheath and insulation can melt and make a pipe live then that's just bad workmanship - and the regs prohibit that directly.

Even the 18th Edition says earth heating systems,

Read it again - especially the bit about extraneous-conductive-parts (and the definition of an extraneous-conductive-part in Part 2 of the regs). Its also says bond, rather than earth - which might give you a clue about it's intended role (which isn't to trigger ADS).


   - Andy.