My Complete DIY Rewire

[JohnW2]

... we're talking about overloading a 27A rated cable with MAX 32A which might melt a cable (I think it's very unlikely), and if it did, it would do so very slowly. Risk of fire would come from somewhere else and would be a separate issue.

As I've said, I agree with that. It would take a LOT more than 32A to cause a cable with a CCC of 27A to melt and/or catch on fire. However, we have to accept that compliance with the regulations does not allow one to take advantage of that, which is why we would not design a circuit on that basis. However, that is, IMO, different from a situation in which the design has a (normal) CCC >32A but, in certain (very rare) fault situations it could fall to 27A.

Kind Regards, John

 

[PreferNotToDieOrBurn]

Right let's move on...

I feel I should ask an obviously stupid question in order to get this thread back on track....

How about this:

Should I completely remove old cables or should I just cut them off....

 

[JohnW2]

I feel I should ask an obviously stupid question in order to get this thread back on track....

You don't seem to have got the message that we have all got fed up with your original thread because of your persistent failure to accept advice you didn't want to hear. That's why, IMO, this thread needs splitting, so that your original one can then be left to die its death.

Kind Regards, John

 

[PreferNotToDieOrBurn]

I feel I should ask an obviously stupid question in order to get this thread back on track....

You don't seem to have got the message that we have all got fed up with your original thread because of your persistent failure to accept advice you didn't want to hear. That's why, IMO, this thread needs splitting, so that your original one can then be left to die its death.

Kind Regards, John

I've put out the challenge to point out one thing which isn't safe/to code - nothing as yet. Also this thread is as much about documenting the process as it is about asking for advice.

 

[ban-all-sheds]

I was talking about actual safety problems (fires etc),

You don't have to fall off a motorbike for riding without a helmet to be a safety problem.

You don't have to crash your car for driving without a seatbelt on to be a safety problem.

You don't have to get lung cancer or heart disease or COPD etc for smoking to be a safety problem.

You don't have to have a cable damaged by overheating for not complying with Ib ≤ In ≤ Iz to be a safety problem.

 

[JohnW2]

I was talking about actual safety problems (fires etc),

You don't have to fall off a motorbike for riding without a helmet to be a safety problem. ....

I've explained what I meant.

JPEL/64 clearly have not so far regarded ring finals (under either normal or fault conditions) as sufficient of a 'safety problem' (per your meaning) to cause them to take any action to curtail their use. When the next DPC (for Amd4 or '18th edition') appears, you will have an opportunity to see if you can influence their thinking.

Kind Regards, John

 

[ban-all-sheds]

I've explained what I meant.

I know.

You are wrong.

JPEL/64 clearly have not so far regarded ring finals (under either normal or fault conditions) as sufficient of a 'safety problem' (per your meaning) to cause them to take any action to curtail their use.

I know.

They are wrong.

The fact that they would not countenance their introduction (something I am sure of, and I suspect you are too) shows that would not regard them as a good idea.

Therefore logic says that you stop allowing them.

When the next DPC (for Amd4 or '18th edition') appears, you will have an opportunity to see if you can influence their thinking.

They have been through the debate before.

As someone maybe once said, it is not possible to change by reasoning positions not arrived at by that method in the first place.

 

[JohnW2]

When the next DPC (for Amd4 or '18th edition') appears, you will have an opportunity to see if you can influence their thinking.

They have been through the debate before. As someone maybe once said, it is not possible to change by reasoning positions not arrived at by that method in the first place.

If you don't want to even try, that's obviously your prerogative, but it seems very unlikley that the sort of change you would like to see will be forthcoming in the absence of such representations.

Kind Regards, John

 

[securespark]

Threads about rings v radials tend to just go round and round with little agreement

I beg to differ.

The arguments about rings go round and round, but the arguments about radials just go back and forth.

 

[EFLImpudence]

 

[JohnW2]

I beg to differ. The arguments about rings go round and round, but the arguments about radials just go back and forth.

Given that we're talking AC, they also probably go back and forth (at the same time as going round and round) in ring circuits

Kind Regards, John

 

[bernardgreen]

If a wire overheats it will first melt, more than likely (extremely likely I would say) causing a short and tripping a fuse BEFORE there is even a vague risk of fire.

If the wire has got hot enough to melt it is much hotter than is necessary to start a fire.

If the wire got red hot without tripping the fuse then the current rating of the fuse was many times too large for the cable it was supposed to protect.

Please get an electrician to do the work for you as it is obvious you do not understand what function a fuse or MCB is intended to do.

 

[JohnW2]

If the wire has got hot enough to melt it is much hotter than is necessary to start a fire.

To give him/her the benefit of the doubt (if that is deserved!), although what (s)he wrote was "wire", I think (s)he was probably thinking of the insulation, rather than the conductor, melting.

Kind Regards, John

 

[333rocky333]

Should I completely remove old cables or should I just cut them off....

If poss remove them, its misleading to future tenants discovering them and not knowing if live or not.

also bag it up and you will get back a few bob as scrap

 

[stillp]

the reason they did all of that was that, in their own words, "keen to maintain the use of the UK ring circuit". So not for any sound engineering reasons.

They might have been keen to maintain the use of the ring final for sound engineering reasons, they just didn't bother to explain their reasoning to you.

I still can't find it, but there's a document somewhere (HSE? Eurostat? ILO?) that points out that the UK has about half the rate of "electrical incidents" of the next lowest country in Europe. All (as far as I know) of those other countries use radials, so even allowing for statistical errors, we seem to be doing something right. Remember that although there are no pan-European standards for electrical installations, each country's wiring regulations are derived from a series of IEC standards, so cable ratings, installation methods, and circuit protection are basically the same across the continent.