17th Edition, RCD's and Cable routes

Toby · 2008-08-14T15:54:55+00:00

Hi,I can't seem to see anywhere that is selling the new onsite guide yet - maybe it hasn't been printed yet!? (Where is the best (cheapest!) place to get a copy of the regs?)I understand that all circuits that are not proved to be mechanically protected need 30mA RCD protection.The house I have just bought has old breakers in a rewritable fuse box (Plug in replacements to the fuses, a bit like this But with two buttons on the front (trip and reset))I plan to replace it with a 3 way unit, with two RCD's and a non protected section, so I can RCD the lights separately from the sockets, have the fridge and freezer on the non protected side, and have a feed to the garage in SWA off the unprotected side.I assume the SWA is ok, as it is protected "out of the box" so does not need to be connected to an RCD in the house (It will go into a RCD or RCBO protected consumer unit in the garage, so the circuits there will be protected, and as the garage is very close to the house, the TN-S earth will be exported (I assume it is still OK to use the steel wire as earth, so I only need 2 core cable?))If I were to run twin and earth from the unprotected side in the house, can this just be clipped to the sides of the joists under the floor, or will it need protecting even under there to be compliant?If buried in a wall, I assume it needs steel capping, I assume this needs earthing too - if so, where to, am I supposed to cut into the CPC of the cable I am protecting, or do I need to run a separate earth cable back to the CU (if so, what size?)?How about running it through a hole the wall to the back of an IP66 box (to then connect the SWA to, feeding the garage?), do I need any other protection here, like a short length of metal conduit?Many thanks!Toby...