Ring main...or not

[Ben]

Hi,

Can anyone advise? I have what I think is the ringmain in a room, set into the brickwork behind the plaster. It runs at the same level as the sockets, and looks exactly right for a ringmain. It has been chased very badly such that at certain points it rises proud of the plaster (corners etc). However, it has a brass outer skin. This made me think gas pipe, but there is no gas pipe of that description going from the meter, and no gas in the room. My voltstick registers nothing, but the brass would shield it anyway, so that's no surprise. Any thoughts? Is this just a bely and braces solution to stop people accidentally chopping the cable?

Cheers,

Ben

[dom]

How old is your house? Old enough to have had gas lighting?

Is it of unusual construction e.g. solid granite?

The cable may be pyro, a copper jacketed cable intended for surface mounting, (e.g.on solid stone walls) and the plaster added subsequently.

[Lurch]

On 13 Apr 2007 10:11:57 -0700, " [e-mail]" mused:

That was my first thought. There are a few houses round here that have suffered damp problems on the groun floors so downstairs sockets have been run in in MICC. As it`s got an earthed metal cover then you can run it pretty much wherever you want too.

[Ben]

The building is 1920's, but has been retrofitted with new electrics at some point. The wire in question crosses a blocked in fireplace, so it can't be original. It is chiseled into the brickwork for most of its length, except a few places. I'm on the top floor, so I doubt that damp is a problem.

Ben

[Lurch]

On 13 Apr 2007 11:17:00 -0700, "Ben" mused:

Does sound like it could be MICC. Can you not expose a bit and provide us with a photo?

[cynic]

take a look at the wires in one of the accessories it serves

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[John Rumm]

(no need to post four times - we heard the first!)

[Ben]

By the time they make it into the socket boxes they are two black insulated cores (makes live/neutral identification interesting!)

A photo is here:

suspect the suggestion of MICC may be correct though.

Ben

[Ben]

Yeah, I'm not sure what went on there. I think it was each time I refreshed the page it resent the post data and added a new post. Sort about that :-)

Cheers,

Ben

[Lurch]

On Fri, 13 Apr 2007 20:13:34 +0100, John Rumm mused:

Whoever did the polarity and installation tests should have identified the conductors. The black wires you see are site applied, the actual presentation of a terminated MICC pot is actually 2 bare copper wires. You can get sleeving in most colours which makes identification easier, but most people use exclusively black sleeving and coloured tape for some reason.

Seven and counting. ;)

[Ben]

Thanks for that. If I want to in insert a socket into the main is there anything special to know about this cable, or is it just like any other - since it's unlabeled I'll have to do a continuity check to work out live and neutral. How about earth? Is the sheath used for that...?

Cheers,

Ben

[Lurch]

On 13 Apr 2007 14:45:27 -0700, "Ben" mused:

Gogle MICC termination and tools. Costs a fair few quid for the proper kit and not many people can actually terminate MICC properly.

Usually sheath is earth, yes.

[James Salisbury]

Ah, Yes the earth is the sheath, but special tools and glands are need for the cable ends if is just a one off you may find it better to get the pro in, and warn them it is a MICC cable....

[John Rumm]

One option if you don't have the tools and experience, and there is no particular reason to need MICC, is going back to T&E for the new wiring, and replacing the existing MICC at the point(s) you plan to join to the ring.