13 Amp socket tolerances

[ARWadsworth]

Considering I gave details on how to test a hi-integrity radial without disconnecting anything then even a retard like yourself should be able to test one.

[ARWadsworth]

Only if you understand fault protection. Something far too complicated for someone of your limited learning ability.

[ARWadsworth]

Well that's you unable to test one then. Is that why you do not like them?

Not to do it properly. You need a £299 tester.

How often do you think? Every 50 years is my guess. But enough of your brain.

[John Rumm]

Visual inspection and an ELI every 10 years would be reasonable. More specific test if you notice any other fault symptoms.

The CPC could have 50 ohms impedance and a socket tester will still pass it.

Different day different tune?

As above, you test when you install it.

Just as well you can find faults and fix them then.

Socket testers have a place, but they are not a substitute for a proper low ohms continuity tester, or an earth loop impedance tester.

[John Rumm]

But not as lucky as if he had won the lottery jackpot.

[John Rumm]

Now you are just being silly. You need the same equipment to test either. Look at the test procedure in the back of the OSG.

Not sure that stands any scrutiny...

What typical faults can we have?:

1 High Resistance L/N 2 High Resistance CPC 3 Disconnected L/N 4 Disconnected CPC 5 Transposed L/N

(I will ignore other transposition errors since they will result in immediate non functioning or trips etc in most cases)

User observable

Radial Ring

1 Maybe Maybe 2 no no 3 Yes Maybe 4 no no 5 no Yes

Potential additional risk user is exposed to

Radial Ring

1 High Moderate 2 High Moderate 3 Low Moderate 4 High Moderate/Low 5 High None

(implications of 3 & 4 vary depending on whether the disconnected wire is just disconnected from the socket in question, or actually breaks continuity in the circuit)

No, that's some difference, and there is certainly no clear winner...

[John Rumm]

So how many 20/16A radials would you put into the kitchen/utility room?

Wouldn't do what?

You forgot to answer this yet again...

Well if we ignore the obvious point that 12A sockets did not actually exist at that point, we could look at the quote from the 11th edition:

From Regulations 202 C, D and E together with Schedule 23:

"up to three 15A sockets may fed via a 7.036 (4.52 mm^2) cable two 15A sockets via a 7.029 (2.93mm^2) cable and up to six 5A sockets via a

7.029 (2.93mm^2) cable"

Well firstly, many including myself would maintain that your suggested design will make for a less flexible installation. Probably at a higher cost. You have also not presented any convincing arguments that it would be in any way safer - especially as you keep failing to address why you believe the potential problems of long term overload are more severe on ring circuits than on radials.

Most first fix electrical work is done by professionals. They generally don't do it your way as far as I am aware.

I am not repeating what you said, I am highlighting the error in your sub classing. You said "it doesn't have to be a radial it can be a tree or anything else" - thus implying that a tree or "anything else" would not be a radial.

Had you have said that a radial does not have to be a linear chain of sockets, then I would have agreed with you.

[dennis]

It will find a lot more faults than it could in a ring. And it requires no skill. Do you actually think people are going to get their rings tested by a professional every 10 years? Do you actually think you could trust an electrician to test it correctly. Posts in this thread suggest you are just wrong on both counts.

And then every 10 years as you stated above. It isn't going to happen.

But it doesn't happen, doesn't happen is as good as can't. You are wasting your time doing things that don't work. Come to think about it that is one of your main arguments you have against what I said, taking more effort to do.

No but there is some chance they will get used, you can have as many circuit testers as you like but if they aren't used they may as well be scrap. A socket tester will find most faults on a radial and sod all on a ring.

What are you going to do? make testing compulsory every ten years. That will be popular, well amongst testers it will.

[dennis]

A householder can plug in a socket tester and find nearly all faults on a radial. He can find none of the possible faults on a ring. So ho is being silly, someone that puts in circuits that the user can't find faults until something bad happens or someone that installs a circuits that are better protected and the householder can find most faults with a £2.99 tester that he can use every day if he wants at zero cost.

This is ring mains not just radial rings.

The appliances won't work if there is a high resistance L/N on a radial.

A socket tester will show a disconnected CPC on a radial

A socket tester will show switched L/N on a radial.

There is no difference in the risk

There is no difference in the risk

There is no difference in the risk

there is no difference in the risk

What varies is how easy they are to find and hence get fixed. As other posters have shown its quite easy to get a ring to be a pair of 2.4 mm2 radials with incorrect circuit protection. As other posters have shown its essentially undetectable As other posters have shown these risks run for decades without being fixed

You can say what you like, the facts are: the faults happen, they are essentially undetectable, once there they exist for decades they cause real dangers you should design to avoid them

its easy enough, never use a breaker with a capacity higher than the cables. don't rely on the user doing everything correctly to protect the fixed circuit.

Well if you answer the questions incorrectly there is bound to be a difference in the results.

[dennis]

Why don't you answer it.. look in your book of tables as to what the maximum sustained current you can get through a 20A breaker and post it here.

Then you can tell us how much it exceeds the capacity of 2.5 mm2 cable.

One thing I can tell you is that its a lot less than it is with a 32A breaker.

You keep on arguing the same thing even though it is obvious that any circuit using 2.5mm2 cable and a 32A breaker is not as safe as the same

2.5mm2 cable and a 20A breaker. Its not as though you can even state that its a doubled up 2.5mm2 cable as it doesn't have to be when its installed and it can have undetectable faults that make it a single 2.5mm2 cable with a 32A breaker.

If you can't actually see that as a problem then there is no point talking to you about it.

thats what i said, they need to maximise profits.

There was no error in what i said.

No where did i say what the topology of a radial is. I just thought you didn't know it could be a tree as you think its harder to install than a ring.

Anyway I am bored with your repeating of the same wrong arguments so consider this thread closed.

[ARWadsworth]

It's called not ripping off customers.

If a customer specified a certain sized cable then the customer would get that cable and they would pay extra for it and for any extra work involved in installing it. The profit would remain the same.

[Andy Wade]

And people with no skill will be unaware of its existence and of any need for testing. They will simply call an electrician if something stops working or if they start getting shocks.

That's more likely to happen than regular use of a socket tester by Joe Public. Formal testing - now the EICR - is pretty common in the rented housing sector and for commercial & industrial installations (covered by the Electricity at Work regulations).

Why do you have such an obsession with this matter? Ever considered that your house is (most probably) fed via an unfused spur - '100 A cable' teed off a circuit fused at 300 or 500 A in most cases. The 60 or 100 A fuse in the supply cut-out provides downstream protection in a manner somewhat analogous to a 13 A plug fuse. (Don't push that analogy too far.)

[ARWadsworth]

There was no silence and dennise has managed to talk through his ring.

[Andy Wade]

In commercial and industrial installations where there can be circuits with a high load factor it's common for oversized cables to be specified. The saving on energy that would be wasted in a smaller cable soon pays for the larger one.

[Dave Plowman (News)]

The common ''socket testers' are no more than a rough check and shouldn't be used by those who don't understand such things.

Do you read what you write? That socket tester will show up exactly the same faults on either ring or radial. But, of course, not test either properly.

I hope everyone reading this has the sense to ignore your advice.

[ARWadsworth]

Most special needs persons usually have an compulsive obsession with at least one subject.

[Neil Williams]

I'm with you on that one - the one big danger of a ring over radials is that incompetent work (say a householder swapping a socket faceplate themselves) can create an invisible problem whereby it becomes two separate radials on the same breaker by breaking the ring. This could theoretically cause a fire, as the breaker would be somewhat overrated for a situation where one of the radials was overloaded and the other not (e.g. if the break was very near the consumer unit, leaving one radial with far more sockets than the other).

But how often does this *actually* happen?

Neil

[Neil Williams]

...

...

Thanks for that - makes sense - I hadn't thought about the other issues when considering the effect of a broken ring.

Neil

[ARWadsworth]

How often does what happen? The fire or the incompetent work?

The fact is that most ring circuits are not very often fully loaded for very long in a normal household. A break in the ring circuit will cause an imbalance in the circuit load and cause premature ageing of the cables that are overloaded.

There is more danger from poorly connected terminals causing overheating.

[Dave Plowman (News)]

AOL. By far the most common faults I've come across on any domestic power circuit. I blame the 'electrician's screwdriver' for this.