- 11 Jan 2004
- Reaction score
OK.It's actually not what I would call conduit. It's something I believe they used in times gone by. It is a fairly thin copper tube (~5mm) which I believe has an inner sort of ceramic insulator. This goes to a metal junction box with a metal gland and the box is earthed so the pipe will be. From there it goes with a short cable to the consumer box. But this is probably my biggest area of concern in that the concrete above it is cracked (not sure how deep the pipe is) but the earth wire in that is all that carries it to the garage, so if that alone broke (it's very old) there would be no earth. I'd assumed that if I put in another earth spike any short would take the path of least resistance to ground which would be either to that one or the existing depending, but if the single earth wire were to be damaged the external circuit would have a backup from the new spike and the external consumer unit. In the long run I will probably get the electrician to put a new external supply to it as I noticed there are spare connections on a Henley block in the Consumer unit but thought this might be a simple interim measure.
Sounds like you have a length of MICC cable. A copper sheath filled with a hygroscopic compound (Magnesium Oxide) compressed around the conductors.
To have a fusebox with 32A and 6A CPD's on the end of a spur off a ring final is pointless. And you can't really have MICC cable buried direct in the ground. It is fragile and once damaged, moisture will easily penetrate the Magnesium Oxide and cause a short circuit.