17th and RCDs

[Bay Man]

Are all circuits to be RCD protected? It is possible to have any circuit not protected by an RCD as before?

Many people had the freezer not on the RCD but on a non-protected part of the consumer unit.

[John Rumm]

No

Yes in some cases:

if the circuit cable is visible (i.e. surface mounted or in trunking), or if its protected by earthed shielding - e.g. in metal conduit, by using SWA, MICC, or a specifically designed "earthshield" type cables.

Now that RCBOs are significantly cheaper, that is a viable option here. Give the circuit its own RCD and then only a fault on the freezer will cause a trip.

(there is also rumour that the first amendment to the 17th edition will introduce provision to have non RCD protected circuits again, in some circumstances (probably when extending an existing non protected circuit and it can be argued that the extension makes the installation no less safe than before).

[cynic]

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The 17th was as guilty of introducing confusion and panhandling as the

15th was with its bonding requirements. I had a theory that came about because of the presence of the cable manufacturers on the regs committee. Maybe the same could be said about the RCD manufacturers having input to the 17th?

[js.b1]

Easiest is surface run cabling.

Next easiest is a BS8436 cable such as Guardian, Earthshield or Flexishield. It does not require special glands or special termination, it does mandate a Type-B circuit breaker and a maximum of 32A for a ring final circuit wired in 2.5mm.

Then it is MICC/Pyrotenax, but that requires special glands and termination.

SWA must have glands accessible for inspection and testing.

Alternatively put the freezer on its own 16A/20A radial with dedicated RCBO.

[Andy Dingley]

Pah! We (a terrace of Victorian houses) recently had a letterboxed leaflet from a NICEIC sparkie advising us of Part P and the fact(sic) that we now MUST have our installations brought up to 17th Ed standards by installing RCBOs, and paying one of Part Prescott's minions to do so.

Clearly work is short.

[Toby]

Trading standards need to be notified of this!!

[John Rumm]

Probably worth a complaint to NICEIC as well...

[js.b1]

Followed by the Charities Commission...

Perfect time for a national letterbox campaign including a printed copy of the relevant pages of SI2006... ... including the electrician's front door.