Hall of shame

I have been in this property for three years now and only recently discovered that the downstairs study/dining room is connected to the upstairs ring while all the other rooms are on the downstairs circuit.

I tend to find extensions are often wired in peculiar ways. Our conservatory lighting is wired off the main ring main which was extended into the conservatory, at least there they used a FSU for the lights but left a 13A fuse in which I replaced with a 5A. Our last house which had a kitchen extension also had some peculiar wiring which was in keeping with the total mess the rest of the house was in when we moved in.

As someone on the group to which I posted by mistake commented, turning off the main switch is probably best practice (even if it does mean resetting clocks afterwards).

Whatever kind of circuit you're going to work on, turn something on, ideally the light or socket you'll be touching. Pull the fuse/breaker and go straight back to confirm what you turned on is now dead. Sometimes you will be surprised.

In the old days, you could carry the fuse in your pocket to ensure nobody else plugged it back in, and the early circuit breakers plugged into the same fuseholders for compatibility, and could also be removed.

I'd have thought that with a leakage detection breaker, you shouldn't feel anything. I sometimes worked on an oscilloscope that had the (unshielded) mains fuse sitting on top of the chassis at the rear. Occasionally the workshop radio would go off, and I'd look up to see who had turned it off, finding that it had been me. Never felt a thing.

As the saying goes, I couldn't agree more (hence the subject line).

I have a couple of sockets downstairs which are fed from the "upstairs ring". I have labelled them to this effect for someone in the future.

Unfortunately, they don't work that way. They do not limit the current that can flow through your body at all. They just limit how long it lasts for. John

Disconnect time for 30µA RCD/RCBO should be under 300ms, often they're faster than that ...

Contact or non-contact probes aren't expensive ...

Always confirm a circuit is dead. Easiest way is with a non-contact sensor. First check the sensor is working using a known live somethingorother, then check your circuit is dead, then re-check your sensor is still working on a live wire.

Is it a bungalow ? :-)

since when did 30µA RCD/RCBOs exist?

The lowest I can find is 30 mA.....

I was in B&Q on Saturday and noticed they still had loads of packs of rewireable fuse wires plus boxes of 3,5 and 13 amp cartridge fuses but none for 10 amps. Has this rating gone out of favour ?.

Also noticed that they are selling MK double switched sockets with 'wago' connectors on the back. £6.50 each though and they looked rather bulky. I don't think you could retrofit them into a 25mm backbox.

I have added a double socket downstairs next to the BT master socket where the builder never put a power socket. I fed it from the upstairs ring but via a fusible spur. The cable is fixed to the surface of the wall which is then covered with

People on ADSL might find that their download speeds suffer while the line 're-learns' the correct speed though. Happened to me.

With an old enough installation, you could still be surprised. There was a bang and a flash when my uncle cut a "dead" cable in the house he'd moved into - he hadn't realised that it had fuses on both live and neutral and he'd "isolated" the circuit by pulling the wrong one!

My brain thought two "milli" prefixes looked wrong :-P

For us, we don't want to shutdown our home server, network switch and router - as that kills email for all our phones, including two of our sons away at university and stops their access to our network, where they store their university work. It also disables the "landline" and often the server does not reboot first time (a race condition between devices starting) and as it has no monitor connected, it's a pain to see what's happened.

From what I remember, 2.5mm T&E is rated at 23A in conduit, I think it is about 18A fully enclosed e.g. in insulation or thin plaster.

The ring is only rated at 30/32A as there are two paths anywhere, it's still 23A cable.

Chalet bungalow :-)