Strange thick-walled black plastic conduit.

[Andrew]

My 1976 semi has the standard metal wylex meter box inside the front door inset into the cavity party wall.

The SEEBoard (EDF) incomer comes under the front porch, up through a corner of the slab under the front door cill (inside some gas pipe !!!), then along the *top* of the slab for about 3 feet then up a chase in the party wall and into the metal meter cabinet and into the company fuse.

My garage is one of a semi-detached pair between each pair of semis with a metre wide path separating gge from house.

A few years ago I smashed up the concrete path and discovered a black plastic pipe parallel to the 4 inch salt-glazed pipe that contained the 3/4 inch black iron gas pipe connecting the gas meter in the gge to the back boiler in the house and then onto the kitchen. At the time I assumed that this was put down by the ground workers for connecting the gge to the house for power, but all the electricians did was run a 'tough' spur from a socket inside the house, down under the path (also inside some gas pipe) and into the gge.

Today (boredom set in) I dug down inside the garage to find the end of this black pipe and managed to push a 5 metre length of uPVC window trim all the way. So clearly it is heading towards the metal wylex meter box but I don't know where it terminates.

The pipe (conduit?) has an OD of 48mm and an ID if 32mm, so much thicker walled than normal conduit and it is just black plastic. There is no metal layer in its wall.

Does anyone know what a hefty conduit was used for back in 1976 ?

Was the original intention for SEEBoard to run power into the garage, install the meter and company fuse there and have 7 metre-long tails to the existing meter box location ?. Mystery

How could I find where this conduit terminates ?. Is there some sort of bluetooth sender that could be strapped to the end of the uPVC trim and detcted from above the slab inside the house ?. It is so tough I don't see how it could have been curved up under the existing meter box anyway.

[Andrew]

Could this actually be alkathene water pipe and not kosher electrical conduit ?. I can't think of any other reason why it would have such a thick wall, and if it is, it's much too large for domestic water supplies anyway. It could still be a useful way of getting 10mm electric cable from the meter to the garage without stringing it around the front of the house, but only if I can find out where the other end is.

[Theo]

I don't really know what was standard in the 70s, but a previous 70s house I lived in had the cutout, meter and fusebox in the garage. Are you sure the meter box is original?

Maybe the conduit was a way to run power to the garage for people who wanted a home workshop? I can't think of anything else the 70s might have used conduit for - too early for datacomms or EV charging, unlikely location for TV/FM. Don't suppose it might be plumbing related, eg for a sink in the garage?

As far as detection goes, I doubt Bluetooth would go through concrete but induction might. Put a coil on the end of your 'probe' and run say an amp of audio frequency current through it. Then wave an induction coil around and see if you can pick up the frequency and target where it comes from.

If you were able to turn off every mains circuit in the house and just feed your 'probe' with 50Hz, a cable detector might do it. But better a directional coil with a (battery) amplifier and headphones.

You may also find a USB endoscope useful to see what's going on. I have the USB one of these:

shows up as a USB webcam so works on anything that accepts one of those - there's a USB webcam app for Android that I use it with. Quality is reasonable, although there's a limited focal distance so often things too close are blurry.

Theo

[Andrew]

Definately. There are over 50 terraced and semi's all built to the same basic 3-bed design, and all with a Wylex metal box just inside the front door inset into the party wall. Between the two meter boxes of adjacent houses (inside the cavity party wall) is a pad of heavy duty ?rockwool.

The lower part has a chipboard back panel onto which the company fuse and meter are screwed. Above it is a section where the rewireable fuses and isolation switch are fitted.

I think this was the standard way of supplying electricity to new houses built in the 60's and 70's.

This is all original builders work. Nothing to do with any previous owner and another house that had an extension built found the same wierd black pipe. Homemakers of Saltdean (who went bust in 1991) just built estates of kit-build houses, so they would not have considered extra usage of the (detached) garage. My first house was a mid-terrace version of the same design of house further down the estate with exactly the same type of internal meter, just inside the front door and set into the cavity party wall. Some of the end-of-terrace houses to this design have a white plastic box outside on the end gable holding the company fuse and meter but with the 'fuse box' inside the house under the stairs.

At 48mm OD this is way too large for domestic plumbing.

OK