Is an RCBO an adequate replacement for an isolator?

[Doctor Drivel]

You mean cheap. The drive towards electric heating post WW2 promoted the ring. The advantage of the ring is that many sockets can be on the ring. Great for offices with lots of computers. But on the Continent using radials that is an expensive undertaking. I believe some companies adopted the UK 3-pin sockets so they could have the fuse in the plug (essential for a ring). The UK 3-pin plugs are the only plugs that have a fuse in them - that I know of. They may have some on the Continent specifically for office purposes. Then they have a cheap way of having many computers around the office.

[Doctor Drivel]

S/fix sells the cheapest RCBO at around £28. Les than £20? Where?

[ARWadsworth]

At an electrical wholesalers. I pay a lot less than £28 for RCBOs

Adam

[John Rumm]

I can only assume you don't understand the concept of fault protection. The device needs to cover three fault scenarios: earth fault, over current, and fault current. Should any of these conditions be detected, the device needs to disconnect the line supply to the circuit.

The technology used in both SP and DP devices for all of these activities is identical, so the detection response will be the same. The action of either is to interrupt the the line supply to the circuit.

That the DP device interrupts the neutral also has no bearing on the effectiveness of the detection or interruption.

There are circumstances where disconnection of the neutral is beneficial and desirable, but these are *not* related fault protection capabilities of the device.

[John Rumm]

BS1362 plug and socket systems are in fairly common use around the world

- especially in countries where the UK has had a strong influence.

A common roundup would seem to include:

Sri Lanka, Bahrain, UAE, Qatar, Yemen, Oman, Cyprus, Malta, Gibraltar, Botswana, Ghana, Hong Kong, Jordan, Macau, Brunei, Malaysia, Singapore, Kenya, Uganda, Nigeria, Iraq, Tanzania, Zimbabwe, Belize, Dominica, St. Lucia, St. Vincent, Grenada, and Saudi Arabia.

The requirement for a fused plug is nothing to do with the circuit topology, but is a function of allowing a circuit to be protected at a significantly higher current limit than the appliance. Fused plugs are required on radial power circuits in this country for the same reason.

The lack of plug fuses in continental systems limits the maximum circuit current carrying capacity dramatically. This requires a proliferation of circuits to meet modern usage patterns, resulting in more cost and complexity with no gain is performance or safety (in fact with a reduction in safety).

[John Rumm]

And would you care to tell us where unmetered power was actually provided?

[Steve Firth]

I followed the instruction.

[js.b1]

Indeed :-)

Quite a few street lights round here had their cables running off in the direction of the nearby house, I presume to their cutout. That would explain the "dig for electricity" in some areas - until the metering people checked upstream meters!

I recall there was a "flat fee" system for lighting at one point, with heating sockets being charged for. You could almost say E7 was "unmetered" - I recall 2p/minute evening for 300bps telephone (Micronet) and 1.6p/unit for E7 overnight kWhr.

[js.b1]

MK MG MEM 1-module RCBO are typically =A314-16-19 on Ebay for boxed new. TLC do them for about =A323 off the top of my head.

Comes down to the brand, quantity & person and which wholesaler.

14 RCBO can be had for =A3250 which is not that bad - consider how much 14 MCB and 3 100A RCD cost :-)

[Doctor Drivel]

Some device that isolates the L & N when it activates must offer a higher level of safety.

[Doctor Drivel]

Saudi Arabia? They have anything that goes.I have seen many types there. No EU country want to know it except Ireland, who are tied to the apron strings of the UK.

For a ring to safely work it needs the correct fuse in the plug.

An appliance fuse can offer the correct protection. I have seen appliance fuses in France, whereas in the UK they would not be there. Ina ring with

32A mcb at the CU, needs the fuse in the plug for correct protection. Many appliances that need 6A fuses have 13A in the plug. The system is open to abuse. The fuse is primarily to protect the appliance cable.

Which is a good thing as it gives more protection as an appliance on a ring can be hopelessly out of protection range if such a simple thing like a 13A fuse is installed, when say a 3A is needed.

Mr drivel detectoris on and identified some. A properly installed radial system offers greater protection, especially with DP RCBOs.

[Dave Plowman (News)]

'They' propose lots of things there are votes in. Haven't you learned anything?

So you think nuclear power stations costs nothing to build too?

Time you went back into treatment. Although that expensive German clinic doesn't seem to have helped.

[Dave Plowman (News)]

Don't you start with the red herrings. ;-)

[Dave Plowman (News)]

It's the envy of many. A pal visiting from the US couldn't believe just how flexible it was - he'd been told we still used lots of different plug sizes. And was most impressed with how quick you could boil water in an electric kettle.

But all this thread shows is dribble knows even less about house wiring than heating...

[Doctor Drivel]

The key word was "proposed". The nation was to be all electric, hence electrical supplies to homes capable of heating the home electrically. The dirty Gas industry, making gas from dirty coal with ugly gas works in urban areas was to be scaled down. The downturn in nuclear because of accidents and the discovery of North Sea Gas changed the strategy.

[js.b1]

For TT - yes.

For TN-C-S - no, not at all. With PME both N&E are joined at the cutout, so you just disconnect N yet E is still connected - so no logic there. You must not isolate E under BS7671 reg blah-blah-blah (can't recall the damn number). Three pole isolators are for L1 L2 N not LNE (contrary to some numpties I've met).

[Dave Plowman (News)]

That's one of the situations where you should dedicated radials, actually. Please stick to what you know about. Which will make your posts brief in the extreme.

[Dave Plowman (News)]

Why not go the whole hog and isolate the earth too? Makes as much sense.

[Doctor Drivel]

Comes down to the brand, quantity & person and which wholesaler.

14 RCBO can be had for £250 which is not that bad - consider how much 14 MCB and 3 100A RCD cost :-)

[Doctor Drivel]

This one need effing tagging. One weirdo!