spurs off my kitchen ring main

[hermetic]

I have done Part P work which gets inspected by the local councils elec building inspector (for a fee of course) so you can do it because your training shows you are a "competent person" TBH filling the form out is much more onerous that the installation is difficult! In reality little has changed in the basic domestic wiring situation, apart from the (now reduced) requirements of part P of the building regulations and many of the IET tables are lifted from the IEE books (you can tell by the typeface!) You are right about RCD's, and people were killed in the days when they were not fitted to lighting circuits, the problem is, what happens when the electronics inside the RCD fails, but the RCD remains in the on position? RCD's and MCB's do NOT fail safe, which is why the IEE regs used to state that "No mechanical device shall be fitted into any installation as a SOLE means of protection against overload and fault current! In other words, you use a fuse as well as a back up. So if the MCB/RCD fails, as it will if it is slow cooked by a loose connection in one of the pressed metal clamp style steel terminations in modern CU's, the next level of protection is the 100A fuse in the cutout! that is why consumer units are catching fire, a phenomena unheard of til very recently!! Also the CU's were made of inflammable plastic, as opposed to non flammable phenolic, like the old Wylex units were
I have the National diploma in Elec engineering, the Elec inspector had the Higher National diploma, extra year at college, which they wanted me to do as well, but the slide rules were doing my head in, an electronic calculator cost £60 and I was earning £14.00 for 44 hours! I started in 1967 doing 44 hours for three quid a week, and had to go in on saturdays mornings, when the bus fare cost more than I earned for the 4 hours! An if you told that to the kids today, they wouldnt believe yer etc etc!
Phil

 

[dobbslc]

£28.50 a week when I started!

 

[brightspark]

£28.50 a week when I started!

3 quid a week when i started i wouldnt even work for £ 28.50 an hour now

 

[MetalMonkey]

Ring mains and the associated BS1363 plugs and sockets were invented in the UK in 1942 and came into common use in 1947. They were introduce at least partially to cut the number of fires caused by overloaded radial circuits.

Curious as to where you got this from - as far as I'm aware the main reason for ring final circuits were to save on materials cost.

The ring was developed to replace the inferior radial circuit, which carries cumulative unbalanced current. You CANNOT unbalance a ring circuit to any meaningfull amount, and anyone who says you can is showing a remarkable ignorance of how current flows in a ring circuit. the introduction of ring circuits caused a massive reduction in house fires and electrical accidents in the home.

I wouldn't call radial circuits inferior - many would suggest they offer many advantages over rings.
You can certainly unbalance a ring circuit quite easily by moving the load about - as to whether this is by a meaningful amount depends on your definition of meaningful.

This is by far the nicest little demonstration I've seen of this:

The biggest problem with rings, in my opinion, is when they become two radial circuits - i.e. they break somewhere.
Then you have a cable which, depending on installation method, could have a maximum current capacity as low as 20A protected by a 32A device.
Usually when this has happened it is not even obvious without testing.

So for that reason I would consider a ring far more of a potential fire risk than a properly installed radial circuit.

Today you pay about £3000 for a five week training course (I kid you not) and EVERYONE passes. So have standards fallen? Down a fekkin crevasse, they have!

The route to qualified electrician is still an apprenticeship, college, time served, and city and guilds exams.
The short courses are really a bit of a scam to part the clueless from their hard-earned, they certainly aren't considered worth anything by anybody in the industry.
Problem with them is they give those that take them the impression they are going to be trained - where as previously it just came down to whether you were competent rather than qualified, and that's not necessarily the same thing.

 

[dobbslc]

The biggest problem with rings, in my opinion, is when they become two radial circuits - i.e. they break somewhere.

It one of the most common faults I find in houses and on sites!
I've wired my house in 4mm radials on 16A breakers.

 

[bigegg]

Guys, I want to put a few spurs off my kitchen ring main buit am not shure what is and isn't allowed.

I want spurs for the hob extracter fan, dish washer and cabinet lights like this.

First is this allowed, i.e two spurs from each double socket. if yes should they be wired in 2.5mm?

If not allowed, what are my options?

Thanks

View attachment 310923

Something that I've not seen mentioned: if you put a 13A FCU spurred off from each double socket, then you could connect the extractor fan + cabinet lighting on one spur, and the dishwasher+lighting on the other?

 

[mike os]

Something that I've not seen mentioned: if you put a 13A FCU spurred off from each double socket, then you could connect the extractor fan + cabinet lighting on one spur, and the dishwasher+lighting on the other?

Yes, but the total load on the leg is limited to 13a by the fcu, same as a socket outlet

 

[bigegg]

Yes, but the total load on the leg is limited to 13a by the fcu, same as a socket outlet

Yes, but it answers the original question ...

 

[hermetic]

Curious as to where you got this from - as far as I'm aware the main reason for ring final circuits were to save on materials cost.

The ring circuit and the associated BS 1363 plug and socket system were developed in Britain during 1942–1947. They are commonly used in the United Kingdom and to a lesser extent in the Republic of Ireland. ... The design chosen as the British Standard was the flat pin system now known as BS 1363.
They do not and never have saved on material costs, this is a myth!

I wouldn't call radial circuits inferior - many would suggest they offer many advantages over rings.
You can certainly unbalance a ring circuit quite easily by moving the load about - as to whether this is by a meaningful amount depends on your definition of meaningful.

WHY would you not call them inferior? What advantages do they offer over rings? In a ring circuit current flow is equal in all parts of the ring, if it is BROKEN, it is no longer a ring circuit. Ring circuits break for 2 reasons, someone damages a cable, or they are badly installed.

This is by far the nicest little demonstration I've seen of this:

The biggest problem with rings, in my opinion, is when they become two radial circuits - i.e. they break somewhere

This test is of purely academic interest, in reality the actual restivity of the conductors is MUCH less than the resistors and this is the reason I said it makes no "meaningfull" difference. Also the resistors will have a tolerance, IOW they will not be all identical in resistance.
Properly installed ring circuits do not just "break" the fact that it is happening today highlights the falling standards of installations, and to some extent the fragility of solid conductor cables

Then you have a cable which, depending on installation method, could have a maximum current capacity as low as 20A protected by a 32A device.
Usually when this has happened it is not even obvious without testing.

So for that reason I would consider a ring far more of a potential fire risk than a properly installed radial circuit.

Please explain why? You understand that a radial carries a cumulative current in each leg, so I cannot see how you come to this belief.
This statement is disproved by the massive drop in electrical fires after the introduction of properly installed ring circuits. Also note that ring circuits of today carry nothing like the currents they used to in the days of electric fires and fan heaters.

The route to qualified electrician is still an apprenticeship, college, time served, and city and guilds exams.
The short courses are really a bit of a scam to part the clueless from their hard-earned, they certainly aren't considered worth anything by anybody in the industry.
Problem with them is they give those that take them the impression they are going to be trained - where as previously it just came down to whether you were competent rather than qualified, and that's not necessarily the same thing.

I agree the short courses are a scam, but nevertheless, the people who complete them are registered with one of the part P scheme providers, most will pass their inspection, and will go straight onto a building site and start wiring houses, which is another reason why consumer units are catching fire, something totally unheard of till recently, and the solution of putting it in a metal box with entry glands and fireproof sealer is such a laughable solution from an engineering point of view, that this alone demonstrates that the IET as an organisation is not fit for purpose. I don.t mind being disagreed with, but give me evidence, not opinions.
Phil

Edit, before the ring circuit was adopted, all power including sockets used radial circuits, I thought the ring main had consigned them to the past, I have asked many why they are being reintroduced, never had a satisfactory answer
Phil

 

[RaceDiagnostics]

Does anyone know what I will need to show to building control one my job is finished (in Scotland)?

 

[Blobber]

Ok, Ill do this.

View attachment 310928

Another simple request derailed into pages of bickering, go with this thats perfect, my only alteration would be to put the dishwasher socket on a spur above the work surface so its easy to isolate if you get any problems

 

[Blobber]

Curious as to where you got this from - as far as I'm aware the main reason for ring final circuits were to save on materials cost.



I wouldn't call radial circuits inferior - many would suggest they offer many advantages over rings.
You can certainly unbalance a ring circuit quite easily by moving the load about - as to whether this is by a meaningful amount depends on your definition of meaningful.

This is by far the nicest little demonstration I've seen of this:

The biggest problem with rings, in my opinion, is when they become two radial circuits - i.e. they break somewhere.
Then you have a cable which, depending on installation method, could have a maximum current capacity as low as 20A protected by a 32A device.
Usually when this has happened it is not even obvious without testing.

So for that reason I would consider a ring far more of a potential fire risk than a properly installed radial circuit.



The route to qualified electrician is still an apprenticeship, college, time served, and city and guilds exams.
The short courses are really a bit of a scam to part the clueless from their hard-earned, they certainly aren't considered worth anything by anybody in the industry.
Problem with them is they give those that take them the impression they are going to be trained - where as previously it just came down to whether you were competent rather than qualified, and that's not necessarily the same thing.

I like real world explanations but thats very misleading, that ring would be huge with that sort of resistance!

 

[RaceDiagnostics]

Another simple request derailed into pages of bickering, go with this thats perfect, my only alteration would be to put the dishwasher socket on a spur above the work surface so its easy to isolate if you get any problems

I'm trying to minimise the number of switches/outlets above the worktop to give clean lines and simplify the tiling. Since the dishwasher has a 13 amp plug I'll mount the socket in an easy to access spot in an adjacent cupboard.

 

[hermetic]

With electrical installations, safety is paramount, you can only let so much utter B*ll*x pass under your nose before you have to respond. Having qualified in Electrical Engineering, I can assure you that domestic wiring is very very simple, and as long as common sense is used, plus some regulations for reference, you could train anybody of reasonable intelligence to wire a house in a matter of a few months. Then the government of Mr T BLiar and the ODPM Prestcott decided that the industry needed more regulation, and proceeded to make a right royal F*ck up of it all! Now we have unsafe circuit protection, consumer units catching fire, and multiple faults in new installations due mainly to poor training and poor workmanship. some of it caused by half truths and lies spread on the internet. Just glad I'm out!!
Phil

 

[RaceDiagnostics]

Replaced some flooring while waiting for the plasterer. I'm in two minds about whether to tile the floor in the kitchen area or just go for solid oak/enginerered oak throughout the entire space

 

[hermetic]

Does anyone know what I will need to show to building control one my job is finished (in Scotland)?

In Scotland, no, I don't have a clue, because the legal system is different, BUT, if you are under part P of the building regulations, and relying on local authority inspection then the inspectorate usually require prior notice that an installation is taking place, and usually want to inspect during installation.
Phil

 

[hermetic]

If there are any services under the floor make damn sure they are perfect before you seal them in! Depending on the type of tiles, you may need plywood down first. Either solid or engineered oak will have to be stacked in the room for a couple of weeks to normalise to temperature and humidity before it is fitted FIL was specialits floor fitter, and insisted it was the only way to stop joints opening after installation. Personally I think that sealing the floor to the point where it is totally inaccesible is like welding the bonnet closed on yer car! It has come back to bite me a couple of times, but the wife insisted etc etc!

 

[RaceDiagnostics]

Thanks, my drawings went in last week and the architect got a verbal acceptance on Friday from building control after a bit of toing and froing on other points, I just asked him the same question.

Looks better with a bit of flooring. These flooring websites with a "see what it looks like in your room" are great.

 

[RaceDiagnostics]

If there are any services under the floor make damn sure they are perfect before you seal them in! Depending on the type of tiles, you may need plywood down first. Either solid or engineered oak will have to be stacked in the room for a couple of weeks to normalise to temperature and humidity before it is fitted FIL was specialits floor fitter, and insisted it was the only way to stop joints opening after installation. Personally I think that sealing the floor to the point where it is totally inaccesible is like welding the bonnet closed on yer car! It has come back to bite me a couple of times, but the wife insisted etc etc!

Luckily there is good access under the floor, a hatch in a cupboard and about three feet of space, and enough ****e to fill a skip.

 

[hermetic]

Looks good, but you could almost get the same effect from hiring a floor sander, and then filling and staining, and you would retain access for emergencies! Unless the existing flooring is poorer than it looks, your repairs look very neat!
Phil