Will the electric board Still need to be called out???

[paulfromswindon]

No, it isn't complicted. However, I would state again that I cannot condone or recommend it. Rather than me just be Mr Whingebag, please let me explain why:

I appreciate you want to save the money, but as a professional electrician, I would be very concerned at anyone who is not qualified working on a main cutout. There is a 100Amp fuse in that cutout, and should anything be shortcircuited between there and the meter/consumer unit, I have seen the bang it makes - thousands of amps will flow for a split second before that 100A fuse pops - it once blew the entire end off my pliers (even pros make mistakes!). Should the incoming side of the cutout be shorted out, it doesn't bear thinking about. It only takes a dropped tool or slipped screwdriver to cause a big bang. Also when you pull the cutout and remove the cover to connect your tails, the incoming side will still be live and exposed.

Sorry to be a downer - I appreciate this site is designed to encourage DIY, but there are areas of electrics that I do not believe should ever be carried out by DIY'ers. The board's main fuse and metering is one area that could be extremely dangerous if anything goes wrong, as there is no margin for error, and little protection from a major short-circuit. I appreciate it looks very simple, but I have seen many dangerous things over the years - there is a reason why we do a four year apprenticeship, one of which is because it makes us understand and respect the possible danger!

I would consider booking an NIC sparks to do this purely because he can check that everything is OK before connecting the tails. I appreciate you want to save the money, but this should still work out cheaper than if you got a sparks to change the board in the first place. You'll have the satisfaction of knowing you did the job, and the confidence that all os OK.

Sorry to be unhelpful, but I do have a conscience, and there is a limit to what even a competent DIYer should tackle! Please consider this carefully, and make the right (safe) decision.

Take care

Paul

 

[xbond]

Paul, I will follow your advice & get an NIC electrician to come in to pull the main fuse and install an DP isolation switch.

Part of the problem here is that British Standards are way behind compared to electrical regulations -and plumbing too btw- in continental Europe. I have worked there on many installations before, and I have to say I didn't expect to find a 100 Amp fuse as the only main protection, this was fine about 100 years ago when Edisson first invented electricity but technology has since improved...

In most of Europe, regardless of how old an installation is, the electricity company must provide a main 100mA RCD/circuit breaker -usually set to 30 Amp for a basic house with no electric heating-. That breaker takes care of the worst failures in the installation and no electrician besides the electricity company is allowed to unseal it.

It then feeds the C.U. -with the usual RCDs & MCBs- where you can operate at will since all it takes is to operate the main switch first. All C.U. supplies are readily available at all hardware stores and smart DIYers can happilly and legally commission an entire installation, once again the main circuit breaker takes care of the worst faults.

Just hoping that some IEE members will read through these boards and think of taking their standards to the next level...

 

[breezer]

xbond, i think you are wasting your time in hoping for the regs to be changed, but you forgot one thing you knew what to do and what not to do, some people in this country can not fit a plug top and get it right, i guess its just a case of the electric supply company being cautious

 

[Scoby_Beasley]

I reckon that more people die from electric shock than being 'gassed'.
Does this mean that legislation will be brought in that you need to employ a qualified electrician to un-plug your kettle ??

 

[paulfromswindon]

Interesting debate, can't resist joining in again - My ha'penny worth - Apologies for it being long-winded, but it may explain a few things, and I figure that as avid DIY'ers you would like to understand it in more depth.. If you just think I'm being a smart-alec, tell me and I'll not do it again, but I am trying to help I admit to be being worried about DIY electrics at the best of time, but the better informed you are, the safer you will be.

Firstly, Breezer is correct, the supply authorities are being over-cautious, but rightly so. However they are only being slightly over-cautious. People do die. It's easy to second-guess why this or that is the way it is, or decide that it just doesn't seem right but there are good reasons. Sorry if that sounded patronising, but it's true... Sometimes you have to have faith in the way things are.

Fact of the day: Most people have no idea that It only needs 80 thousandths of an amp (0.08A) to go through you and you will die. In the event of you touching a bare end of your lawnmover cable in the garden, not one fuse in your house will blow as you fry, even if you are there being toasted for hours. The only thing that could save your life is a 30mA RCD, which shuts the supply off at 0.03A of fault current. This is why you should use a Powerbreaker or a modern CU with a 30mA trip protecting all sockets. Sobering. How many people don't use one?

Here beginneth the sermon on why there is a 100Amp fuse:

Electrical systems are designed to protect us when things go wrong, and each level of protection requies a bigger fault to trip it. For example If your kettle goes wrong, the fuse in the plug should go. If you've replaced the fuse with a nail, it can't blow (I've seen this twice). Therefore the fuse in the CU feeding the sockets will blow. If you've replaced this with a thick piece of copper wire cos it annoys you when it blows or you ran out of fuse wire (I've seen this many, many times) it can't blow. The very last line of defence is that 100A cutout. In a normal situation, each progressive level of protection must be less sensitive - therefore the nearer you get to the supply source, the more danger exists.

The lowest rated fuse, nearest the fault, should blow, and nothing else. With a main fuse of less than 100Amps, a fault in the sockets could trip the plug-top fuse, the CU MCB and the main fuse all in one go (Remember, if you short out your kettle, it won't be 14 amps that blows that 13Afuse in the plug - at least several hundred amps will flow for a millisecond or two, it's just that the plug-top fuse should blow first, though in reality it often takes out the CU fuse or breaker as well - an example of poor discrimination, but not dangerous). You should remember that the 100A cutout should never be the thing that blows, there should always be other, lower-rated devices that go first.

The 100A fuse is to protect the main network in the street, not to protect you - that is an important point to remember.

There you go - discrimination - sumarised as the fact that a fault should only cause that appliance, or the circuit that feeds it to fail, and should not disrupt other circuits or the supply as a whole. This is one reason why there is a 100Amp fuse at the source.

On the subject of Isolation, I do think that it is becoming more popular for authorities to put in a main breaker after the fuse which the customer can use. As I said before, I just worked on an installation where SE had fitted a 100A MCB that the customer could isolate. I think it will catch on, and rightly so.

Xbond, sorry to be picky, but a house could never have a 30A main fuse, that would have been expected when each house had a light and a socket. If youhave a kettle, an immersion, and the washingmachine on at the same time, you are using about 40 amps. Fire up an electric shower and a cooker, and you are up to at least 70 amps...

Incidentally, to quell another popular misconception, an RCD won't necesarily prevent the main fuse tripping, and cannot replace it as they do two different things (an RCD is not the same as a fuse or MCB, though you can get combined MCB/RCDs), so there will always be the main fuse first and foremost. An RCD will trip if you short a live connection to earth (ie an earth fault). It will not trip if you have a short-circuit (live to neutral). If you don't believe that, I'll explain but not right now. An RCD can be (and is in the case of overhead supplies in the UK) installed to get over the fact that the incoming earth is not good enough, I suspect this is why they have to fit them abroad. The UK has the best regulations in the world in my view, much safer than most of Europe.

Sorry again to be picky, xbond, but the British Standards are not lagging behind the regs - the IEE Wiring Regs are a british standard. BS 7671 to be precise. And a very good one too In fairness it used to be seperate, though!

I have to agree with Breezer once more. I sincerely hope and trust you guys are competent at what you are doing, but people do some incredibly dangerous things. I have honestly seen many, many DIY jobs where they were incredibly lucky not to have burned thier houses down, or electrocuted themselves. A little knowledge is a dangerous thing sometimes. .

Hope you've found this interesting - and xbond, glad you're going to get an NIC guy to do the work. Believe me, it makes sense.

Finally, Scoby, There may well come a time when only qualified sparks can work on electrics but I doubt it. If the law ever says that you have to pay a sparky to unplug your kettle, I am going back on the tools!! mmmm, I can smell the money.

Take care guys, hope you found some of this interesting. If it p***ed you off, I'll shut up in future

Paul

 

[breezer]

to find out how an rcd can save your life read this
a fuse is there to protect from over loads and short circuits

 

[Scoby_Beasley]

Finally, Scoby, There may well come a time when only qualified sparks can work on electrics but I doubt it. If the law ever says that you have to pay a sparky to unplug your kettle, I am going back on the tools!! mmmm, I can smell the money.

Paul

paulfromswindon,
Am I too old for an apprenticeship in my 40's ??

 

[masona]

Have to agreed on all of above posts.

I used work along the side of the electrician and have learnt about electric as you go along.Like most diy'er we know what to do with some electric work BUT don't really know what does it do and I have to admit I didn't realise how dangerous electric is.I've heard many times electrican saying "oh yeah I had 240v go thru' me blah blah".I don't want to put a damper on this interesting debate but sadly my electrician mate with 29 years experiment was killed last week on building site teaching his son for his apprenticeship.Now I'm seriously thinking twice about electric and hope all you diy'er out there really know what you're doing and if you don't then DON'T do it.

Does any of you guys know, is it rare for electrician to be killed as you must hear it sometime ?

ps Scoby_Beasley, I don't think you need a apprenticeship to unplug your kettle

 

[Tindog]

Don't know what anyone else thinks - but this stuff is really interesting and human beings are prone to learn through experience and not because someone tells us not to do something (kids are the perfect example although adults are just as bad)...

So Paul, when you write these long responses, I think it really helps because if we understand what's going on (with the electrics) then we're able to make informed judgements about what we should do as DIY'ers or when we should call in the professionals - so as far as I'm concerned, good on you for taking the time to explain it without being condascending! Top stuff!

Cheers

 

[xbond]

Paul, sorry I don't mean to start a polemic on the UK regulatory topic, but I strongly disagree that BS7671 are some of the 'best standards in the world and much safer than most of Europe'.

A mandatory combined 30Amp main circuit breaker & RCD has to be safer than a 100Amp fuse -for the network, the installation and people-.

The 30Amp limit works for most houses I've seen -that's 7000W power-, of course in houses using multiple power hungry appliances simultaneously (oven, washing machines...), that limit is increased accordingly by the electricity supplier.

 

[paulfromswindon]

Hi Chaps, glad you found my waffling essay useful.

Masona, sorry to hear about your mate. I have heard of electricians being killed, but I've never known one personally. The truth is, most electricians who get killed on site are not killed by elecrticity, but from falls from scaffolding and ladders and the like. I think it's rare for an electrician to get killed by electrocution, I've only heard of one or two. Having said that, I don't know a single electrician who has not had an electric shock, I have had about 4, one of which really hurt. As I said before, even pros make mistakes - Usually cause by complacency. Understandably, when we work on 415 volts in commercial buildings, we tend to be much more careful, because we know we wouldn't get a second chance.

Interestingly, there was a high-profile case in the trade some years ago where a sparky's sloppy work caused a customer to get killed by electrocution - he did something wrong (inexcusably wrong), then made the situation worse by not correctly earthing the metal sink. He was convicted of manslaughter and I believe imprisoned for six months. It's sobering to remember as a sparky that one could kill someone if a mistake is made.

xbond, sorry, but I can't let it lie The UK wiring regulations place much more emphasis on what happens when a fault occurs. Our earthing requirement are better, the equipment used is better, and the method of cabling is better (in general) - we could debate the pros and cons of each for a long time, but that is my opinion. I'm sure some elements of European regs may be better. It is for each to decide thier opinion, but in fairness, mine is based upon 4 years learning those regulations, and 16 years working to them. Sorry to be patronising, but to say UK regulations are poor is just not the case. The only thing wrong with them in my view is that only a small part of the regs in mandatory. The fact that anyone could legally do some of the things they do is shocking (pun intended)!! That would not be allowed in some European counties. Eg, I saw one person who wired a 34 amp shower in 4 amp flexible cable, then wondered why the cable caught fire when he tested it. Hard to believe people can be that stupid, but believe me, they are out there. The reason I contribute my views to this site is because at least you guys are sensible enough to want to know how to do things safely.

I enjoy a debate, so I just have to carry on: What I also disagree strongly with is that any modern house could cope with a 30Amp main fuse. 7000 watts is nothing - your kettle uses 3000, your washing machine another 3000, your telly probably 1000, if you have 5 lights on, there is another 500. If you have an 8.2KW electric shower, you will pull 34 amps (8200watts) just by having a shower. Do you really feel that the supplier can install a different fuse depending on what equipment you have, then come an upgrade it if you change from a gas cooker to electric, then again if you add a shower? It just isn't practicable. Would customers have an obligation to advise the boeard if they remove a shower so that they can come out and make the fuse smaller? If so, would they do it? The suppliers used to fit 40Amp fuses in the days before showers, toasters, etc. As electric use became higher, they had to upgrade them, and the infrastructure to cope. Nowadays they install a 100Amp fuse because they have decided that a household could require (and is allowed) anything up to this level. All the protection for you is from the consumer unit and plug-top fuses, and RCD if you have one. The 100Amp fuse is not really there to protect the installation (although it may if all else fails), it's to protect the network, and is fine for the job. The network can easily handle the fault current that would occur before that 100Amp fuse blows - it is designed that way. It's a balance between protecting the network, and not putting a fuse in that keeps blowing and inconveniencing customers. How would people feel if the board installed smaller fuses then charged customers 50 quid to come and replace it every time it blew (which it would), or 200 quid to upgrade it every time you installed additional equipment?

There's also the risk of overloading a fuse - you should consider that a 30 amp cartridge fuse could probably carry well in excess of 45 amps or more as a steady load and not blow - they only blow quickly in fault situations. I have been in houses that still had old 40Amp main fuses, and on one or two occasions, they were too hot to touch.

Sorry, I appreciate all this sounds patronising, it's not meant to be, but as i said, I enjoy a debate - ask my wife!!!! Don't take it the wrong way, it's meant to help and inform.

There may come a time (if not already on new sites) when the suppliers install Isolators, but I don't believe that they will ever fit RCDs. The suppliers provide you a safe, high-capacity supply, it is for individuals to provide the protection for the installation. If the suppliers start fitting RCDs, which people would regard as installation protection, how many people will start suing the suppliers if the RCDs fail to trip if something happens because the customers own installation is not correct? Or if they start nuisance-tripping and defrosting the freezer regularly? (and they do go wrong - how many people ever even press the test button regularly on them, let alone get a sparky to do a proper test on them?). It may one day be mandatory for RCDs to protect the whole installation, but it will still be the customer's responsibility and property. I would bet my wages on it.

I really don't mind debating it - quite enjoying it, to be honest, but please trust me that the way things are done have evolved over many years, and have become better and safer with each evolution. There can always be views on whether stuff can be safer, but life is a balance. If you followed the regs to the letter on a domestic installation, it is very very safe, and could very well save your life one day.

Have a nice day folks

Paul

 

[Gees]

Just a note.. European plugs for domestic appliances lamps etc. Dont have ANY protection in the plug at all. At least not the ones I have seen.
So say for instance a short in table lamp flex would probably produce a very hot mains flex. ( before the fuse blows, provided of course that Pedro has fitted a fuse and not a 6 inch nail in the supply....)

Enjoy your holiday...

 

[paulfromswindon]

Quite right Gees, I've seen some sockets with no shuttering as well (so people can stick pins in them and stuff). Better be careful here, or we'll start up a pro/anti Europe debate!

Thought for the day, an example to highlight the subject: how many people have studied the way a UK plug top is wired? Awkward, yes, but not without thought - have a look. They are designed so that if you trip over the flex and pull it out of the plug, the live will come out first, then the neutral, then the earth. Therefore no risk of appliance casing going live. Very clever, methinks.

I have too much time on my hands.............................

Have fun

 

[breezer]

should i keep quiet about the Americans then?


ok, i wont

they are "just as bad" they also have plugs with no fuses, yes ok so they have 110 v but to get the things to run at 110v you have to double the current (that is to say that if you compared the same appliance from here to there, theirs would draw nearly twice as much)

also each socket is has its own fuse (or its supposed to) give me a good old ring main any day

 

[paulfromswindon]

Quite right Sir! I think the americans just wire stuff using wet string!!! Never been there, but seen photos of massive tangles of overhead wires. shudder... Seems they aren't so fussy cos of the lower voltage.

It's settled then. The brits are the best at Lektrics. Shame about football, cricket, making cars, making movies and all the rest, eh? Still at least we (half) built Concord (yey), then scrapped it (boo). Sorry, totally off-topic but couldn't resist.

Have fun