Continental radial socket system better than British rings

[Doctor Drivel]

I tend to agree with this. There are few advantages in the UK de-facto ring circuit system.

- They have live and neutral MCB breakers on their CUs, while we only break on the live.
- We have 32A rings while they have 16A radials to the sockets.
- Our plug tops only protect the live.
- Their circuit MCB breakers, trip at the same current as our RCDs and only trip that circuit.
- In British systems the RCD acts faster than the MCB breakers making them pretty useless as protecting devices.
- In our systems the RCD knocks off all the power (well depending on whether there are protected circuits or not).
- They have heavy loading appliances having their own circuits at the CU, and each circuit its own MCB breaker. No tripping the whole circuit or house, only that circuit.
- Some appliance makers rely on the user to install the correct amp rating fuse in the plug top (say 3 A). Few are ever fitted with 13A being the norm.
- Continental systems have finer appliance protection in the appliance not the plug.

The UK is virtually unique in implementing rings as a de-facto standard. They are NOT mandatory. They came about to cut down on cable costs and were used in ships to ring the ship in lighting circuits. Rings are not outlawed in many EU countries as long as "BS EN" British plugs and sockets are used. The fuse in the plug must be used in rings circuits. Using British sockets and plugs in the EU is not illegal.

A Continental system of live/neutral MCB breakers at the CU and radials can be implemented in the UK, and are available in the UK.

The UK is superior in equipotential earth bonding

I was reading that radial circuits are to be mandatory in Europe. Not sure if this is to be phased in.

 

[reggie perrin]

Are you a qualified doctor?

 

[Doctor Drivel]

Are you a qualified doctor?

Yes, a PHD in recognizing drivel.

 

[Spark123]

I tend to agree with this. There are few advantages in the UK de-facto ring circuit system.

- They have live and neutral MCB breakers on their CUs, while we only break on the live.

Yeah, but what, if any advantage, is there to us breaking the neutral as well as neutral is tied to earth in all standard british systems.

- We have 32A rings while they have 16A radials to the sockets.

We can have 32A radials too!!

- Our plug tops only protect the live.

See the top one!

- Their circuit MCB breakers, trip at the same current as our RCDs and only trip that circuit.

Don't think you are right on this, as it would mean they only have 30mA MCBs??

- In British systems the RCD acts faster than the MCB breakers making them pretty useless as protecting devices.

RCDs don't act as an overcurrent protection device.

- In our systems the RCD knocks off all the power (well depending on whether there are protected circuits or not).

That depends on the design and the preference of who designed the fixed wiring installation. An RCD tripping will not disconnect a circuit not protected by it.

- They have heavy loading appliances having their own circuits at the CU, and each circuit its own MCB breaker. No tripping the whole circuit or house, only that circuit.

So can we, depending on the preference of the designer. An installation should be designed with convenience in mind, taking into account what will trip when an RCD trips.

- Some appliance makers rely on the user to install the correct amp rating fuse in the plug top (say 3 A). Few are ever fitted with 13A being the norm.

It has been for some time a requirement for the manufacturers to fit a plug, in this they must fit the correct fuse. In this instance, the british system is better that the continent.

- Continental systems have finer appliance protection in the appliance not the plug.

So we protect the cable to the appliance as well

 

[plugwash]

- Some appliance makers rely on the user to install the correct amp rating fuse in the plug top (say 3 A). Few are ever fitted with 13A being the norm.

IIRC it is illegal to sell ordinary domestic appliances without a fitted plug. There are loopholes but the vast majority of appliaces come with appropriately fused BS1363 plugs.

anyway putting a small appliance on a 13A plug fuse into a UK ring circuit is no worse than putting it on an unfused plug plugged into a 16A circuit.

Yes you could argure that more smaller circuits reduce the impact of neusense tripping. but then 32A MCBs on socket circuits very rarely trip

personally i think the best option for keeping unwanted tripping down is 32A non RCD circuits with RCD sockets used where protection is required. Small circuits on RCBOs is second best and anything is better than that split load **** that gets installed on minimum cost rewires.

 

[Doctor Drivel]

- Some appliance makers rely on the user to install the correct amp rating fuse in the plug top (say 3 A). Few are ever fitted with 13A being the norm.

IIRC it is illegal to sell ordinary domestic appliances without a fitted plug. There are loopholes but the vast majority of appliaces come with appropriately fused BS1363 plugs.

anyway putting a small appliance on a 13A plug fuse into a UK ring circuit is no worse than putting it on an unfused plug plugged into a 16A circuit.

If the fuse blows, invariably a 13A is replaced in the plug.

It is common to have a table lamp on a 13A fuse on a 32A ring. Safer? Mmmmm...no. If there is a fault the RCD gets in first, in most cases, not the fuse, and the whole house is down. If the RCD fails then the fuse or MCB should cut in whichever is first - usually the MCB if there is a fault. By then someone could be on the floor dead, or a fire started due to over-current as the fuse rating was too high at 13A and so was the MCB at 32A.

Although a table tamp on a 16A fuse is not much better, however they have double pole MCBs with live and neutral switched, and less likely of an RCD switching out the whole house. RCDs are unique to the UK, as Continental systems rely on the circuit MCB and the main supplier Breaker which are current activated.

 

[plugwash]

If the fuse blows, invariably a 13A is replaced in the plug. It is common to have a table lamp on a 13A fuse on a 32A ring. Safer? Mmmmm...no.

And how is this worse than the only protection being a 16A MCB as is the norm in the rest of the world?

If there is a fault the RCD gets in first, in most cases, not the fuse, and the whole house is down.

I think you need to understand the difference between RCDs and overcurrent protection devices (fuses and MCBs). The purpose of overcurrent protection devices is primerally to protect against fire and equipment damage and in combination with earthing shock through indirect contact. they do nothing to protect against shock from direct contact with live parts.

The purpose of RCDs is to protect against small leaks to earth primerally for the purpose of saving people in the unlikely event that they come into contact with a live part (though they are not perfect at doing this and should only be regarded as a backup for when normal measures fail). However this means that faults to earth get picked up by the RCD in preference to any overcurrent device (including a 1A plug fuse).

Unfortunately most electricians put far more than is sensible on the same RCD due to presure to keep costs down. This is what leads to the "whole house out" scenarios you understanablly dispise.

 

[Spark123]

RCDs are unique to the UK, as Continental systems rely on the circuit MCB and the main supplier Breaker which are current activated.

Eh? I don't know a lot about continental stuff but I can't see them not having RCDs in one form or another. RCDs are current activated hence their name: Residual Current Device.

 

[plugwash]

RCDs are unique to the UK, as Continental systems rely on the circuit MCB and the main supplier Breaker which are current activated.

maybe you are not seeing the RCDs because they are integrated with the MCBs to form RCBOs (which is by far a more sensible option than whole house RCDs I agree though RCD sockets are better still) but I am almost certain they are there.

P.S. I agree whole house RCDs are a stupid idea but that is in many ways a seperate issue from low current radial VS high current ring.

 

[Chivers7]

The only good thing I can see in this debate is light switches are lower on the continent allowing kids to turn them on and off with a stool.

 

[Doctor Drivel]

The only good thing I can see in this debate is light switches are lower on the continent allowing kids to turn them on and off with a stool.

They are even lower here now.

 

[RF Lighting]

RCDs are unique to the UK, as Continental systems rely on the circuit MCB

This is the CU from my hotel room in the Czech Republic.

Notice anything familiar?





Them MCBs dont look DP either

 

[Steve]

Years ago when I went on holiday I used to wonder what those units in the CU were that had no switch on them . . . now i know its a contactor for the occupancy key card switch!

And in this country I bet the hotel CUs only have 2 ways! ring and lights!

Rob, whats the 2nd device from the RCD you're pointing at? Looks like another make of RCD, or is it 2 devices?

 

[RF Lighting]

Its 2 devices.

Looks like a SP MCB (probably for the control CCT) and another contactor, or possibly some sort of overrun timer?

 

[securespark]

Methinks DD is talking about RCBO's used on the continent (I've not seen many yet).

However, in defence of the regs, rings are only one option available to the installer. Radials have always been an option - look in the OSG - indeed, years ago, radials were the norm.

They are now coming back into "fashion".