"Electrical Fault" Definition

[JohnW2]

Actually I do wonder about that in relationship to the plastic back. What could have happened in other words if it was a true electrical fault.

Although the OP tarted this thread was asking about 'electrical faults', I think that fire brigades much more commonly talk about 'electrical fires' - and by that they mean that the heat which initiated the fire (heat is obviously always needed) was generated by electricity - rather than by a blowlamp, cigarette, match or whatever.

There aren't many options if the electrics are up to date and they usually come lead attached with a plug. Our new fridge freezer has one.

One hears reports that the moulded plugs which usually come with appliances are particularly prone to overheating - so I wouldn't be too reassured by the fact that an appliance "comes with an attached plug"!

Kind Regards, John

 

[ericmark]

I do wonder where the fluff goes in a washer drier? Our drier has a large filter to collect the fluff, but not the washer/drier. I also wonder if some fires due to filter not fitted correctly, or left out.

@JohnW2 I think nail on the head, electrical fire very different to an electrical fault.

I think we have a major problem in the electrical trade with definitions, transformer, driver, ballast, bulb, lamp, and the list goes on, we have seen changes decimate use to mean kill one in ten, or remove one tenth, today people seem to think it means retain just one tenth. Meaning change.

I was told a circuit was "An assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s)." however it seems I don't need to notify to add a FCU to a ring final to make a radial.

People look for loop holes, and try to twist definitions to suit what they want, so again as @JohnW2 unlikely to use the word fault, as if there is a fault then some one is responsible, so electrical fire means they are not saying anyone was responsible.

 

[JohnW2]

I was told a circuit was "An assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s)...."

BS 7671 still tells you that.

... however it seems I don't need to notify to add a FCU to a ring final to make a radial.

Well, quite apart from the common sense, FCUs are, more often than not, used to supply a single load, and I'm not at all sure that qualifies as supplying "an assembly of equipment" (any more than {usually} does a fuse in a BS1363 plug).

Kind Regards, John

 

[ericmark]

I have used and seen used FCU to supply a number of sockets we seem now to call it a fused spur, I would have called it a radial. The approved Part P documents have left a lot to be desired, they seem to be some ones attempt to translate the law into layman's terms, but electricians are not layman.

The used of works like RCD also causes problems, Recreational Craft Directive is also refereed to as RCD. As to RCCD and ELCB-c and calling them type A and type AC one some times wonder if the aim is to confuse. As to consumer unit, it seems crazy to use that phrase when listing what can be done with or without notifying, as if you don't follow the manufacturers recommendation it will not comply with type testing so is no longer a consumer unit it is just a distribution unit, we all know they should have called it a distribution unit to cover all, but they didn't.

 

[JohnW2]

As to consumer unit, it seems crazy to use that phrase when listing what can be done with or without notifying, as if you don't follow the manufacturers recommendation it will not comply with type testing so is no longer a consumer unit it is just a distribution unit, we all know they should have called it a distribution unit to cover all, but they didn't.

Since (unlike BS 7671), the Building Regs don't define "Consumer Unit", it can (in the context of notification) probably be taken to refer to any sort of DB in domestic premises, whether 'type-tested' or not.

Kind Regards, John

 

[ajohn]

Consumer Unit seems to refer to a household distribution board. We consume electricity in our houses so little matters in terms of what they actually look like they need to contain certain things and meet certain aspects of the building regs - metal and safety aspects etc

 

[JohnW2]

Consumer Unit seems to refer to a household distribution board. We consume electricity in our houses so little matters in terms of what they actually look like they need to contain certain things and meet certain aspects of the building regs - metal and safety aspects etc

It's not quite as simple as that. BS 7671 defines "Consumer Unit" as being a distribution board ion domestic premises which satisfies certain specific criteria, the most important one being that it has been 'type tested' - i.e. it must only contain components (MCBs, RCDs, RCBOs etc.) of the same make as the 'CU' (box!) and recommended by the manufacturer for use in the CU.

Kind Regards, John.

 

[ericmark]

I think we all know Part P is referring to a distribution unit, however we are talking about definitions, where a installation is in the control of an ordinary person type tested units should be used. However I am sure there are many cases where they are not used. I have every intention to use an old consumer unit to fit some sonoff units into to work some of my lights, since I am not an ordinary person they is no rule to say I can't, and since it is not being used as recommended by manufacturer it is not a consumer unit, it is simply an adaptable box. It is not even a distribution board.

I thought for years the L on a plug meant live, but seems all those years I had been getting it wrong it means Line. As to 110 volt plugs with L and N marked on them, seems really an odd marking, what does N mean? It is line two, there is no neutral on a 110 volt system, we would not use the yellow plugs for any other voltage, same with the cable we know it should be green/yellow, brown and black, try buying any, the outer is yellow so clearly for 110 volt but it has a blue coloured core.

We all ignore it, we know it's wrong, but who cares? We all know 110 volt site power is either 55-0-55 or 63-0-63 depending if from split phase or three phase, if the colours are wrong it really does not matter, or does it, if the colour does not matter there then does over sleeving a blue wire to a light switch matter?

It only really matters when an ordinary person is involved.

So we have adopted a name, transformer, they in the main transform either between voltages or currents, but then we have an odd one out, the isolation transformer which does not transform anything all it does is isolate, we know it should not really be called a transformer but it is made the same way as others so we retain the same name.

This has been done again and again, and in the main we have some way to differentiate when we use some new device to replace the old, so where a simple wire wound 50 Hz transformer is replaced with a high frequency transformer and other devices to turn the 50 Hz to high frequency we add a word, we call it an electronic transformer, that's OK, name does not matter as long as we know what it is.

However the ballast and driver are not so easy. We don't say voltage or current in front of word driver we don't even say AC or DC, I worked on aircraft ground lights and understand the whole idea of a current to voltage driver so all lights are the same brightness, current control was always called drivers, now we have units which control voltage called drivers, and no one can tell you what your going to get when you order a driver unless you read the spec.

We by a LED tube, and it says with magnetic ballast simply replace the starter with the new one provided. But how does the ordinary person know if it's a magnetic ballast? OK we know, but there is nothing on the fluorescent fitting that can be read without using a tool to say if fitted with a magnetic or electronic ballast. And often the replacement starter is a fuse, but no label saying fuse, and even the marks that are on them rub off, so very easy to get a fuse and starter mixed up.

It is hard enough for people in the trade, but these definitions must be very confusing to ordinary people. I remember ordering a head lamp, I had been told bulbs grow in the garden, I got a head lamp, minus the bulb, so we look to history, and we had a spigot onto which the lamp fitted, and inside the lamp with has a wick, mantle or bulb depending if oil, gas or electric, so I now always call them bulbs or tubes. Even a cob which is not bulbous I still call it a bulb.

I remember working in Algeria with a fleet of Chev's, trying to work out what a track rod is called in USA was a problem (push pull bar) so we want standard international names. In Algeria we had to have lights on the side of wagons, we called them flur de gabre may be spelt wrong, now used in UK, I have not a clue what they are called, only know the French name.

What I am saying names and definitions matter, we all need to be singing from same song sheet, and when some one asks for a MR16 we need to know what that means, so we can then ask what type of MR16 and not give them some random unit which may or may not work.

 

[JohnW2]

I think we all know Part P is referring to a distribution unit ...

I presume that you are talking about the notifcation rules in the Building Regs, not "Part P" (which says nothing about anything specific).

... however we are talking about definitions, where a installation is in the control of an ordinary person type tested units should be used.

As I said, the Building Regs have NO definition of "Consumer Unit", and certainly say nothing about "ordinary" or "non-ordinary" persons. You are talking about BS 7671, which is a totally different kettle of fish.

I don't think one would get very far trying to convince an LABC (in England) that replacement of a 'something' did not require notification because the 'something' was a non-type-tested DB, hence not (by BS 7671 definition) a "Consumer Unit"!

Kind Regards, John

 

[ajohn]

It's not quite as simple as that. BS 7671 defines "Consumer Unit" as being a distribution board ion domestic premises which satisfies certain specific criteria, the most important one being that it has been 'type tested' - i.e. it must only contain components (MCBs, RCDs, RCBOs etc.) of the same make as the 'CU' (box!) and recommended by the manufacturer for use in the CU.

Kind Regards, John.

That is what I said but rather briefly. The metal does not apply when DNO's fit separate isolators so that electricians can work on and replace CU's. Seems an electrician can not use the plastic type that is used. The electrician can remake connections on one side - perhaps the plastic cu lesson has been learned .........

The alternative if needed is get the DNO to remove supply fuse(s) and later refit when the work is done.

 

[JohnW2]

That is what I said but rather briefly. The metal does not apply when DNO's fit separate isolators so that electricians can work on and replace CU's. Seems an electrician can not use the plastic type that is used. The electrician can remake connections on one side - perhaps the plastic cu lesson has been learned .........

I'm not really sure what you are talking about - are you talking about plastic/metal CUs, or isolators (or both)?

Kind Regards, John

 

[ajohn]

I'm not really sure what you are talking about - are you talking about plastic/metal CUs, or isolators (or both)?

Kind Regards, John

Just something I noticed when our smart meter was installed along with a separate isolator on the supply feed to the CU. I am something of a cynic at times ie one rule for electricians but not for DNO's

The isolator is also in a stupid position when and if we have a new CU installed and not exactly great as things are. Untidy in other words.

 

[ericmark]

My old house has the meter in a box built into the wall and the fuse box in garage, in both cases not really a problem with fire, new house they would have been in garage but now that's part of a flat, above the units is a concrete roof, a little more of a problem but not really a huge problem with fire, but mothers old house the consumer unit and meters were under the stairs, this was a massive problem in the case of fire, daughters the meter and CU entrance to house close to the stairs, not as bad as mothers, but still a bit of a problem in the case of fire.

We know the major cause of fire with the CU was the way the MCB clamp was made so it could end up with the bus bar being pressed against the terminal rather than being clamped, it was hard with some locations to see if inserted correctly, OK may have been the odd faulty MCB but in the main it was the clamp.

The DNO has also had problems with poorly milled screw threads where the torque driver shows correct torque but the screw was binding in the hole not clamping the cable, the fitter would have been better without a torque driver as then he would have felt it was binding.

So one the risk depends on the building, and two the quality of the equipment, and three the skill of the installer. And idea should be prevent the fire, not simply contain a fire once started, I may be wrong, but I don't remember a single fuse box fire with the old Wilex fuse box, even when the base was made from wood.

I agree it would be helpful if we had more information as to exactly why the fires started, I was called to look at one installation where the telephone was doing odd things, seemed likely nothing to do with electric supply, but wanted to show willing. Earth loop impedance readings seemed odd, so did hunt more, in the end found we had been supplied with a populated CU but the whole sale outlet had popped the MCB's into the CU for ease of transport, but did not tighten the screws, there was to be fair a notice saying tighten all screws, but for some in the consumer unit it would require dismantling to get to them, so not very practical to tighten all screws, so all MCB's had ended up without any screws tightened onto the bus bar, lucky no damage so bit of work with screwdriver and all OK.

However be if define Electrical fault, or what is considered reasonable when putting a label tighten all screws can be debated, personally think CU should have been supplied with the MCB still in their boxes or the screws should have been torqued down, as to had there been a fire would the electrician or supplier been found at fault I don't know, likely the electrician?

 

[EFLImpudence]

The metal does not apply when DNO's fit separate isolators so that electricians can work on and replace CU's. Seems an electrician can not use the plastic type that is used.

The "non-combustible material" requirements only apply to consumer units. A meter or isolator is not a consumer unit.

The electrician can remake connections on one side - perhaps the plastic cu lesson has been learned .........
The alternative if needed is get the DNO to remove supply fuse(s) and later refit when the work is done.

Yes, we know.

 

[JohnW2]

Just something I noticed when our smart meter was installed along with a separate isolator on the supply feed to the CU. I am something of a cynic at times ie one rule for electricians but not for DNO's

Fair enough, but I'm still not sure what your point is - are you perhaps observing that meter installers are still installing plastic isolators whereas electricians are not.

DNOs do, indeed, work to rules/regulations which are different from those which apply within installations. However, in terms of what you say, I'm not sure of the relevance of that, since DNOs do not install meters (or post-meter isolators).

Kind Regards, John