What’s going on here?

[Harry Bloomfield]

Can't believe that!
Maybe he had leftover stock?

Nor I, it would be very old stock by then!

and the boxes were made of cheap, glued boxwood, not ply.

There was VIR, run in timber cap and casing, on the surface, with a surface switch.

There was VIR, run in grip conduit, usually with the timber boxes, all buried in the wall.

There was a tough rubber like predecessor to the PVC like T, and T&E. Often buried direct in the wall, with timber pattress, and surface switch.

 

[SUNRAY]

My parents' house (1930s) still had some old wooden boxes left for light switches. The switch plates had little toothed lugs which pivoted outward as you tightened the mounting screws and they dug into the sides of the box.

Wish I'd kept an example.

I'd forgotten those.

The same system is still used in France and Germany with their plastic backboxes.

 

[ericmark]

The problem is, a loop impedance tester is an expensive bit of kit, and without it, even if there are earth wires, you have no idea to if they are connected.

Parents house, built 1954, had wall lights, which should have been earthed under 13th, but that's 1955, don't know what the 12th said. The pendent lights did not need an earth until 1966, so they would have complied.

Found some wood back boxes, and when a boy, I know I ruptured a 13 amp fuse with a line - earth fault, so there must have been an earth to start with, but around 2006 came to do some work there, and only earth I could find was the one for the GPO party line telephone. Not only missing, but no sign it had ever had one. I got a TN-C-S FOC so lucky did not cost to correct.

But without my loop impedance tester, I would have not known it was missing.

Had a doorbell fitted by the council social services, it was a special she could answer from her chair, and needed a 12 volt DC supply, so the 8 VAC removed and a socket with a 12 volt DC wallmart replaced it. I wanted to charge her mobility scooter so thought easy swap it for a double, the RCD tester showed it would not trip any RCD, seems council electrician put it wrong side of the consumer unit. So I asked for minor works certificate, never did get it.

So even when items installed by registered electricians things are missed. So without having a loop impedance tester to hand, I would not fit metal switches or sockets, would take a chance with plastic, but not metal.

 

[Ragnar_AT]

A socket tester, an extension lead and a multimeter in Ohm mode go a long way though. Use the socket tester to confirm a socket close to the light is earthed, turn off the electrics and measure between the earth of the extension lead and the earth you want to check.

 

[NRS]

Great advice above.

And both earths uncoiled, sleeved together and connected to a metal back box with fixed lugs?

 

[ericmark]

A socket tester

It has a loop test, so yes it will work, although the pass mark means no good for a ring final, old good for radial circuits.