Consumer unit regulations change

[Roger Chapman]

Plastic deformation?

[Graham.]

It's badged Belin. We wouldn't have high expectations, but the public might.

I could almost undo the terminals with my thumbnail, and certainly could withdraw the wires after a quarter turn. The screw head has made very little impression on the ferrule, they just needed to give it more welly, but there has been no improvement over several years of using them.

And yes, I did notice the lose strand from the neutral and the slight nick live insulation.

Here is the other end of one I photographed some time ago, to illustrate another failing. Perhaps you can spot what was on my mind?

[tony sayer]

Err no!, pilots baling out over France or the channel somewhere;!...

[harryagain]

It was last used in the early 60s ISTR Then Tough Rubber sheathed. Then PVC/polythene. Quite a bit of overlap. Some people didn't trust new technology.

Before any of those as Vulcanised India Rubber, either in "capping and casing" (wood) or "grip conduit". (metal) Even put in ungeround in timber boxes filled with pitch. I worked on plenty of that but never put any in.

And before THAT was gutta percha insulated, run like trolley wires with ceramic cleats on the surface. Must have dated to Victorian times. Saw it a couple of times.

Underground lead sheathed/steel armoured cable was still being use in the

80s. I installed plenty of that too.

[harryagain]

I took plenty of lead sheathed out. (Valuable scrap with all that lead.!!!) It only perished inside joint boxes/switches etc. where it was exposed. Inside the lead sheath, it was always perfect. Dunno why.

[Dave Plowman (News)]

Not in the UK. Things like IEC mains leads usually have a moulded on plug

- but things like extension leads often not.

[Andrew Gabriel]

It's perished by tiny quantities of ozone in the atmosphere. Inside the lead sheath, it's protected. Conversely, when exposed near switch contacts, that's a disaster for rubber - even with only the most occasional sparks, the resulting ozone rapidly destroys rubber. Rubber could never be used in electro-mechanical telephone exchanges because of the ozone generated by tiny sparks in relay contacts.

[Dave Liquorice]

Oxygen...

[Dave Plowman (News)]

It makes plenty sense. You've obviously got no experience of it.

Given damage to an appliance cord is common, you're talking s**te - as usual. To protect that, you either have a fuse in the plug or use a radial circuit with appropriate protection there. Meaning either a massive CU, or restricting the number of outlets. In practice, both.

[Charles F]

I'd agree with Dave re the requirement for massive CUs on systems with no plugtop fuses. We have regularly rented houses in France, and watched (in newish houses) the number of MCBs and circuits going up over the years. Of late I've seen two bank and (once) three bank CUs - with between 20 and 30 circuits for a 3 bed house. The much maligned 30A ring main and fused plug system does get rid of a lot of this.

I'm certainly not one to think that "everything done here is the best and only way" - but I do think that actually our electrical system is pretty good in international comparisons.

Charles F

[Adam Funk]

But you do get better discrimination with massive CUs, whereas a nuisance trip in the UK cuts off half the sockets in the house.

Yes.

[Dave Plowman (News)]

The UK final ring system offers real savings in installation costs and time - even more so given the ever increasing need for outlets. Which was and is exactly its purpose.

[Dave Plowman (News)]

Aren't you likely to get more 'nuisances' the more circuits you have?

[Tim Watts]

Well, 1/4 in my case...

I like 32A rings. It means you can have a reasonable number of circuits (like 3-4, not 10+) but if someone sticks 3 heaters on one circuit randomly it is likely to cope.

[Andrew Gabriel]

If someone sticks 3 powerful heaters on one circuit, they're going to be getting very hot. That was the whole point of the ring - you are not going to need more than 7kW within the area served by a ring, regardless of the number of socket outlets and appliances doing that.

7+kW is going to make you uncomfortably hot.

The design scales very well - nowadays we have loads more appliances and sockets than when rings were designed, but the design scales perfectly to handle this without sprawling CU's/fuses, as the power consumption is no higher (actually, it's lower since most houses now have central heating, which was not the case in the late 1940's when rings were used much more for heating).

[Adam Funk]

It depends on the nuisance, I guess. In the American system, two plug-in electric heaters on the same circuit will trip the 15 A fuse, but I think those things are less common than they used to be. In the British system, I think the problem is more likely to be tripping the RCD (especially if it's shared over more than one MCB circuit) because of the sum of slight leakages from the dozen appliances plugged into the same ring.

[Adam Funk]

Yes, I agree. But from what I've seen it's still routine for that to be 1/2 unless the customer insists on splitting the circuits up.

[Adam Funk]

Well, I just found it described as

Fireball, better distance than hairspray Easy to use too much

in someone's table of spud gun propellant experiments.

But I'm not sure that list is 100% reliable.

[dennis]

If its -10C outside its going to take more than that to get my conservatory to 22C. I have a CH fed fan heater and a 5kW heat pump + a 20A spur so I can cope.

If I didn't have that then three or four heaters plugged into the mains would be needed.

[Dave Plowman (News)]

You clearly have a comprehension problem.

No matter how often you say wrong doesn't make you right.