# Electrical Safety: Your house and your appliances



## grumpydaddy (Oct 20, 2014)

In the relatively short time I have been a member here I have seen a number of posts that concern me with regards electrical safety.

Let me start by saying I am an electrician but I don't work on houses generally but more typically on workshops and something more akin to hotels etc.

One of the things that has come to light here is that there seems to be a large number of people living in houses where the wiring and fuse board installation is quite old. These older designs worked fine in that they protect the circuits from overloads but that is where the protection stops.

Somewhere along the course of history the wiring regulations changed and later installations started using MCB's instead of fuses in homes. There was also the introduction of RCD's which added another level of protection in that these were designed to protect the occupants from electric shock in the event of a faulty appliance. Mostly these were fitted in the "fuse box" also known as a consumer unit and offered protection on all the sockets in a house at once.

These days one can get systems using RCBO's fitted to each circuit individually to achieve the same level of safety on all circuits.

In my experience appliances such as Irons, Kettles, Toasters, all of which have heating elements fitted are the usual culprits when I attend a failure. *Coffee machines* are most likely to fall in this group.

Here are a couple of links to help clarify:

http://www.electricalsafetyfirst.org.uk/guides-and-advice/electrical-items/fuseboxes-explained/

http://www.electricalsafetyfirst.org.uk/guides-and-advice/electrical-items/rcds-explained/

http://www.diydata.com/electrics/fuses_mcb_rcd_rcbo/fuses_mcb_rcd_rcbo.php

So, what am I saying here? For your own safety and that of your loved ones you should at least consider some sort of RCD protection, preferably for the whole house but if not then RCD sockets which you can plug in those items I listed above. Having the Consumer Unit replaced is not cheap but in doing so you will get an inspection done which will confirm the condition of the house wiring is good.

Other members that are electricians might have better links and explanations but the bottom line is....

I want all of us and our families to still be here tomorrow.

EDIT: for the more technically minded among you: http://www.westernautomation.com/DemystifyingRCDs.pdf


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## Dallah (Jan 31, 2015)

Would it be worthwhile to have a portable RCD for my machine to plug into, even if the consumer unit already has RCD within it? I'm wondering if it adds more protection or if it is just overkill? Would it also help protect my machine if a spike came through the power supply?

I ask because recently within our neighbourhood, a transformer was hit by lightening. A power surge went through to all the house served by that transformer and blew out phones, tellys, computers etc.. Would an additional RCD help to protect my expensive toy from another hit like this?


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## Thecatlinux (Mar 10, 2014)

Nope the only additional protection you would get from 2 RCDS in parallel would be if one was to fail, The test button will reveal if the RCD is working correctly .

An RCD will not provide you any protection from a fault upstream , if you wanted to protected from surges you would need a surge protection device such as the ones used for IT/computer equipment .


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## Dallah (Jan 31, 2015)

Thecatlinux said:


> Nope the only additional protection you would get from 2 RCDS in parallel would be if one was to fail, The test button will reveal if the RCD is working correctly .
> 
> An RCD will not provide you any protection from a fault upstream , if you wanted to protected from surges you would need a surge protection device such as the ones used for IT/computer equipment .


Thanks for that. I had no clue (obviously) that an RCD does not provide protection from surges. You may have saved my toy in the future.


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## grumpydaddy (Oct 20, 2014)

In a house with no rcd protection a portable plug in unit is better than nothing in that it protects one item (provided you remember to use it) It could also be used as a basic fault finding device for http://coffeeforums.co.uk/showthread.php?24731-Gaggia-Classic-Electric-Shock&p=316479#post316479 which I assume has no other.

I was recently faced with another problem that has arisen because insurance companies are thinking that PAT (testing) is a panacea and a great get out of jail card when having to pay out.

Let us suggest for a moment that we PAT test (a misnomer I know) a kettle. To do so we switch it on and test.... Said unit either passes or fails

Now let us suggest that we test an item like a washing machine or a coffee machine that has electronic control: We switch it on and test..... while the controller is telling it to fill maybe so it may well pass and the test is complete before the heating phase of its cycle begins. Faulty heater circuits may well not be found by "PAT testing".

Whole house or individual circuit protection probably seems expensive until someone is hurt...... and yes I have an electrical burn on my wrist from a good few years ago. Yes it hurts, yes it CAN kill, but for me the true frightener was ... I COULD NOT LET GO.

I believe I am right in saying that houses sold recently or tenants changing in a property is an event that requires an electrical inspection BUT as it is not my area of work I am not sure if just that is enough to require the property to meet current regulations, probably not. Any alterations to said property should though. For those of you that rent that would include provision of fire alarms and perhaps emergency lighting

Happy to see additions or clarifications from you guys that do houses


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## risky (May 11, 2015)

This is a bit of an eye opener for me. My house is Victorian with a 'fuse box' that isn't much newer. There are no switches, I have to physically pull the fuse out of the box to disable the downstairs lighting for example.

Any ideas how much an electrician would charge to update this? Am I looking at needing the house rewired?

Also is there somewhere you would recommend for buying a plug-in RCD? I don't even have one for the lawnmower which means I'm likely to get an electric shock if I accidentally mow the cable, is that right?


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## Jon (Dec 3, 2010)

Think a consumer unit is about 300 fitted around here?


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## jeebsy (May 5, 2013)

risky said:


> This is a bit of an eye opener for me. My house is Victorian with a 'fuse box' that isn't much newer. There are no switches, I have to physically pull the fuse out of the box to disable the downstairs lighting for example.
> 
> Any ideas how much an electrician would charge to update this? Am I looking at needing the house rewired?
> 
> Also is there somewhere you would recommend for buying a plug-in RCD? I don't even have one for the lawnmower which means I'm likely to get an electric shock if I accidentally mow the cable, is that right?


I know a cracking guy if you decide on a rewire, he did mine and my sister's (well, her fiancee's - some of the wiring there was almost 100 years old and and wasnt earthed - said it was one of the worst he'd seen)


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## 7493 (May 29, 2014)

Risky, I cannot comment on the likely cost of a new consumer unit or potential re-wiring, however, you can purchase a plug-in RCD for the lawnmower from many outlets e.g. B&Q and I strongly advise that you do so! I've cut through a hedge cutter cable a couple of times and the house RCD has stopped the machine in milliseconds with no detriment to me.

If you cut through a cable you are unlikely to get a shock if the machine is double insulated. (Most are.) However, without the RCD, the exposed end of the cut cable would most likely remain live and pose a considerable hazard.


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## grumpydaddy (Oct 20, 2014)

Those plug in units tend to be about £8. Getting a rewire or part rewire is completely dependent on what needs to be done but a turn of the last century property around here would cost £2K ballpark but you might find there are options like do some prep yourself if the old is going to be discarded later. Lots of factors may change that price though.


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## risky (May 11, 2015)

Blimey. Here's hoping it doesn't come to that. Thanks for all your info.


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## Rhys (Dec 21, 2014)

I remember my grans old Victorian house had bakelite fuse holder that you unscrewed, then wrapped fuse wire around terminals. Once over, some people used any old bits of metal if they hadn't got fuse wire. In those days, you had two types of round pin plug, normal sized 13A and smaller 5A. The plugs didn't have fuses in them at all!


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## grumpydaddy (Oct 20, 2014)

I remember them well.



> BS 546, Two-pole and earthing-pin plugs, socket-outlets and socket-outlet adaptors for AC (50-60 Hz) circuits up to 250 V is a British Standard for three pin AC power plugs and sockets. Originally published in April 1934, it was updated by a 1950 edition which is still current,[1] with eight amendments up to 1999. BS 546 is also the precursor of current Indian and South African plug standards. The 5 A version has been designated as Type D and the *15 A* as Type M.* BS 546 plugs and sockets are still permitted in the UK, provided the socket has shutters.*


I also remember plugging things into the lights with a bayonet style adapter that had a twisted pair of cloth covered wires leading away so, no earth at all.

Risky: Let me try to give you a little hope...

My father rewired the house he rebuilt about 35-40 years ago (with some help) That has twin and earth cables but still had rewireable fuses until more recently.


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## risky (May 11, 2015)

I've got some of the smaller sockets. Weren't they usually for lamps? Also a couple of points where there was some kind of heater. There is a spare fuse box in the cupboard with each fuse labelled for a different heater.


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## grumpydaddy (Oct 20, 2014)

Probably the old economy 7 storage heaters. At one time there was probably a separate meter and time clock that heated these overnight on a cheap rate for the power then you opened the heater through the day for warmth.

That you still have round pin sockets is not great news though.


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## grumpydaddy (Oct 20, 2014)

Anyone with small children needs to read this:

http://www.fatallyflawed.org.uk/


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## aaronb (Nov 16, 2012)

Completely agree with you OP, but if you think here is bad try posting on Reddit - there are some real idiots on there who have narrowly avoided death (I hope~) by not doing what they intended when pointed out how unsafe it was.

If you are intending to use a plug in circuit breaker do check that it is rated for wherever power your espresso machine is using with the heating element on. A bigger machine can probably draw close to the full 13a and some cheaper ones may not be able to handle that.

I also don't get the fascination here and on reddit with buying 110v appliances. Again you probably need a heavy duty transformer as the cheapo ones cant handle much, and then you have to pay import fees and duty anyway so its not really a bargain.


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## 7493 (May 29, 2014)

If you have the very small round sockets feeding switched lights they are still in use today with dinky little plugs that have half insulated pins. If you have the larger 5 amp and 15 amp ones that is not good news.


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## jlarkin (Apr 26, 2015)

Great thread, thanks for posting many things to consider here already.


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## mrsimba (Mar 17, 2014)

Thankyou!

I've just been out and bought a 'circuit breaker' plug to go onto my coffee machine socket as I still have the 'old' style fuse board - so many thanks again for the thought provoking information!

Cheers

Simon


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## grumpydaddy (Oct 20, 2014)

Glad to hear this has been of use or at least thought provoking to at least some of you.

Remember RCD plugs, adapters and sockets are just like those consumer unit types in that they need to be tested by pushing the test button regularly.

If your interim measure is to use these then start with equipment that uses water and is made of metal then move on to items that get handled like toasters and stuff with heaters in.

For outdoor stuff like mowers and pond pumps this is also a possibility.


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## risky (May 11, 2015)

aaronb said:


> I also don't get the fascination here and on reddit with buying 110v appliances. Again you probably need a heavy duty transformer as the cheapo ones cant handle much, and then you have to pay import fees and duty anyway so its not really a bargain.


Is this not 110V as used commonly (legally) in industrial/commercial applications? I'm not sure why people would be obsessed with this but in industry it obviously makes sense. Device does not require 240V to run, therefore by lowering it to 110V there is less risk to the user if they are electrocuted.



grumpydaddy said:


> Anyone with small children needs to read this:
> 
> http://www.fatallyflawed.org.uk/


Very interesting indeed! Although I'm sure when I was little I got an electric shock off a socket, but perhaps my parents had socket covers on that I had partially removed.


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## aaronb (Nov 16, 2012)

risky said:


> Is this not 110V as used commonly (legally) in industrial/commercial applications? I'm not sure why people would be obsessed with this but in industry it obviously makes sense. Device does not require 240V to run, therefore by lowering it to 110V there is less risk to the user if they are electrocuted.


Grumpydaddy or thecatlinux can explain it better and more accurately than I can, but its more to do with the current then the voltage. 50v with a high amperage could give you a nasty shock as well.

In an industrial setting with a properly installed 110v supply there shouldn't be an issue, I was more aiming that at people who buy coffee grinders and plug them into a cheap 110v transformer from Maplin, then wonder why everything goes pop.


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## Rhys (Dec 21, 2014)

risky said:


> Is this not 110V as used commonly (legally) in industrial/commercial applications? I'm not sure why people would be obsessed with this but in industry it obviously makes sense. Device does not require 240V to run, therefore by lowering it to 110V there is less risk to the user if they are electrocuted.


I've always disagreed with this. You lower the voltage and the amperage goes up. Amperage is more dangerous than voltage. Interestingly enough, as far as I know they have scrapped the law that says all site equipment should be 110v. Maybe they've (whoever dreams this stuff up) have woken up to this fact. Always makes me laugh on site that they go nuts about 110v but everyone has 240v battery chargers for their cordless drills and radios.

We still use 110v though for our mixing drill and cement mixer as we've had them a while. we had to buy a lower KV tranny box as our old bigger one always trips consumer units.


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## risky (May 11, 2015)

aaronb said:


> In an industrial setting with a properly installed 110v supply there shouldn't be an issue, I was more aiming that at people who buy coffee grinders and plug them into a cheap 110v transformer from Maplin, then wonder why everything goes pop.


I wasn't aware people did this. Very strange behaviour!


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## grumpydaddy (Oct 20, 2014)

Goodness such a lot at once.

110v as per USA is generally designed to run at 60hz so a cheap converter that does not change the frequency too may well cause issues. .....depends on the kit.

110v as per UK building safety rules is in fact just 55v over and under Ground potential. Theoretically then you get a 55v shock to earth if there were a fault. No reason then to drop this safety rule

Smaller transformer was needed due to the larger one having too great an inrush current at switch on most likely.


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## 4515 (Jan 30, 2013)

One of the first jobs that we did when we moved into this house was to rip out the old dis board and replace it with an RCD protected board. We split a lot of the circuits at the same time and added a second board to supply the kitchen

The garage was fed by a metal conduit around the side of the house which had a L and N single cables which were not very heavy duty. What was more worrying was that the conduit was really rusty / corroded and this was used as the earth. When we replaced the feed to the garage the fluorescent tubes started much easier as there was less voltage drop with decent spec cable used.

What was even more concerning was that the games room is fed from a (probably 6mm) armoured cable - more than capable for the job. The issue was that the games room was fed from the garage dis board so shared the same flimsy cables in the conduit that fed the garage. A real accident waiting to happen !

Luckily my brother in law is a spark and did all the clever bits of the work - I was the labourer / tea lad.


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## grumpydaddy (Oct 20, 2014)

That is the way to do it.... be the labourer do the prep. Most sparks don't like that bit anyway


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## 4515 (Jan 30, 2013)

grumpydaddy said:


> That is the way to do it.... be the labourer do the prep. Most sparks don't like that bit anyway


Cant complain.

He rewired one of our previous houses with 'stuff' that he had left over from other jobs. Cost me £1.79 for a junction box for the total rewire .... and the beers for two nights


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## Thecatlinux (Mar 10, 2014)

110v transformers for use on construction are isolation transformers ,this means there is no physical connection to the supply .

The principle of the transformer works by induction, because you are isolated from the supply and because the voltage output is 55v (peak) it is impossible for you to receive a fatal shock.

RCD work on a different principle but used correctly will also make it very unlikely for you to receive a fatal shock.

well done grumpy dad for all you information you have posted feel a bit guilty I hadn't put any input , quite happy to answer questions just didn't want too bore people but it appears people are genuily interested.

plus if it saves someone getting hurt its a worthy thread.


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## grumpydaddy (Oct 20, 2014)

catlinux; My bag is maintenance and not very typical buildings either so your thoughts an any of this are more than welcome. I'm thinking of doing 2391 (2394 & 2395 now apparently) meantime I am somewhat behind on some stuff so again error correction is good.

Folks if it comes to safety and you have a question then ask....

We may well even be able to help


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## Brewer in training (Feb 7, 2015)

working dog said:


> Cant complain.
> 
> He rewired one of our previous houses with 'stuff' that he had left over from other jobs. Cost me ï¿½1.79 for a junction box for the total rewire .... and the beers for two nights


Have you got his number???

My mate rewired the supply to my garage for my compressor, power, lights and alarm.

Learnt all about divorced earth's, split load rcd boards, mcbo's, harmonised wiring and NIC/EIC inspections.......

Interesting stuff.....

He also checked out my coffee machine with a PAT tester and a MEGGER and pronounced it safe......

Had to put a gearbox in his van as payment....... Now that was a PITA........


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## 4515 (Jan 30, 2013)

Brewer in training said:


> Have you got his number???
> 
> My mate rewired the supply to my garage for my compressor, power, lights and alarm.
> 
> ...


The bar bill was much more than the cost of the JB - marginally cheaper than his day rate I recon


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## Thecatlinux (Mar 10, 2014)

grumpydaddy said:


> catlinux; My bag is maintenance and not very typical buildings either so your thoughts an any of this are more than welcome. I'm thinking of doing 2391 (2394 & 2395 now apparently) meantime I am somewhat behind on some stuff so again error correction is good.
> 
> Folks if it comes to safety and you have a question then ask....
> 
> We may well even be able to help


Inspection and testing is a worthwhile qualification to have ,

Basically any domestic installation built to the latest regs would require earth leakage (RCD) protection on all circuits , There has always been particular requirements for dwellings which have a garden or outside space to have Additional form of protection by the means of RCD as the likelyhood of equipment being used outside the Equal Potential zone is quite likely and therefore the risk factor much higher .

The Biggest and latest change to regulations 7671 Amendment 3 which is now in place and relevant to your conversation is the construction of fuse boards in a domestic environment Now have to be of a non combustible construction eg :all metal construction .


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## Brewer in training (Feb 7, 2015)

working dog said:


> The bar bill was much more than the cost of the JB - marginally cheaper than his day rate I recon


Bet it was more fun than swapping a gearbox on a Renault trafic on the ground.........

And you didn't spend 3hrs cleaning crud out of your ears, so he sounds like a better option.......


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## grumpydaddy (Oct 20, 2014)

I think steel dist boards or metal enclosures is from January.... to give suppliers a chance to shift old stock at half the price of the new ones


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## Jon (Dec 3, 2010)

True. January it is.


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## Thecatlinux (Mar 10, 2014)

Yup it is from January , but as default I am already fitting these , there are piles of the plastic ones in the wholesaler and the price seems to drop on a weekly basis I am sure someone will snap them up .


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