# Earthing



## bmat (Feb 6, 2008)

I found that when working for local authority (council), they find it good practice to install a bathroom fan. Their preferred method is to have a fused spur outside the room (for maintenace) and a double pole pull cord switch to switch on or off when required.


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## chrisb271 (Jul 6, 2007)

Hi chaps , strange isn't it that we can use twin and earth with a reduced cpc,this as you point out is the only acception to the rule of equal sizing but i'm sure that somewhere down the line someone will want to change it.

I've always thought it strange that having a switch just outside the door of a bathroom was acceptable be it for a fan or a light switch , does everyone dry their hands everytime before they come out of the bathroom and switch off/on the light ?

Also now with the 17th edition out every circuit going into a bathroom has to be RCD protected , think the IEE or is it the IET now ? has got some deal going for the inclusion of RCBO's :laughing: 

Awhile ago there was talk of getting rid of the ring main for the use of radial circuits , must be the step back in time idea.

Wonder what they will change in the ammendments ? ( should be due out any time now for another 50 quid stump up :laughing: )

Its a mad world 


Chris


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## chrisb271 (Jul 6, 2007)

Ps

Refering to stepping back in time 

Well the 17th edition says that if your twin and earths are less that 50mm deep then you have to protect them with an RCD ( GFCI ) BUT to wire a house and NOT have to protect the cables with an RCD then the cable needs a steel covering like conduit ( capping isn't good enough as we have always known )

How many homeowners are going to want the whole house doing in 20mm galv conduit or will the manufactureres bring black enamel back into full production.

Not so very long ago everyone was ripping out the old 5/8ths conduit systems in their houses,maybe in hind sight we ought to have let them be :laughing: 

Chris


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## Trimix-leccy (Dec 4, 2007)

This is where the 'open to interpretation' falls down.
I read it that RCD is only required if less than 50mm coverage *AND* outside prescribed installation zones:blink: unless ccts are in a bathroom then you need an RCD anyway.

I have still to get my head around an economical AND compliant way of RCD protection without dropping other ccts out

I am thinking
Local RCDs outside bathroom for bathroom ccts
No RCD on lighting [if in zones]
RCBOs for socket ccts and showers
Radial for fridge / freezer
Radial for washing machine /tumble dryer on 2 spurs

Could use split board but then we have 1 socket off-all sockets off
Other option is 2 split Boards with upstairs power and downstairs lighting off one board and vice versa 

What are the views of the UK Jury:whistling2:


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## cornishsparks (Oct 14, 2007)

It seems hard to comprehend.
Front end main switch 30ma RCD is not allowed to control the whole board.
But every circuit above 50mm must have RCD protection, seems like two 30ma rcd,s is the only answer? Do you put one RCD for sockets and one for lights. os split the house up and down, or fit individual expensive RCBO.S.
What about the smoke alarms? RCD OR NOT
What abour meter tails, its not always possible to put the CU right on the back of the outside wall, if the cables run down the wall to the DB do they need to be in steel conduit(32mm) ? or RCD protected,where do you put the RCD cant put it in the REC box.
Personally i never put a cooker on an RCD, you never know how good the customers elements will be, Always fitted 45A switch and not a cooker control unit,
Every socket you fit up to 32A must be proteced by RCD
WHETHER DOMESTIC OR INDUSTRIAL.


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## chrisb271 (Jul 6, 2007)

Sorry trimmy , thats how i read it too , i was just taking the pi55 out of the regs and the [email protected] that knocked it up.

I'm glad i gave up the domestic stuff as i see problems arrising with clients questioning their bills mainly,think of the hassle having to explain to them why you had to put three RCBO's in the consumer unit " hell yeah ,they only cost 32 quid each but in my little red book it says i have to put them in ! " 

How many people do you do jobs for who say " 7000 quid , yeah sure , here you go mate , will need the garage wiring next week and its only going to cost me 2000 quid , bargain ! " 

So the government in their wisdom was to introduce something called Part P so you can't fiddle with your electrics in certain places and you have to get someone qualified in to do it ,that will cost the householder a wadd thus we'll try and stamp out the DIYer, next we'll bring out the new regulations that say you have to stump up buckets full of cash to fit some stuff in your consumer unit called RCBO's or something like that,that will triple the cost so we come back to square one with DIY Dan trying to save himself a quid and doing something dangerous ! Simple :laughing: 

Chris


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## chrisb271 (Jul 6, 2007)

cornishsparks said:


> Every socket you fit up to 32A must be proteced by RCD
> WHETHER DOMESTIC OR INDUSTRIAL.


 
easy , just fit 63 amp sockets in everyroom then cornish ! :jester: :laughing: 

Chris


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## Trimix-leccy (Dec 4, 2007)

Sorry, just driven 400+ miles today to see my youngest in the England Uni Team Hockey trials, set off at 0500h and just got back. Not thinking clearly as the Red Bull [ASDA variant] is wearing off.

I meant switch fused spurs not 'spurs', so no sockets.
Apparently some RCBOs are SP and I think we have to use DP....it gets worse and worse:no: 

NICEIC were meant to contact me about an update seminar , filled all the ****e in on their 'portal'!! [think it may have been tonight, whoops] they seem keener on the multitude of 'come and take the Kings shilling and join our merry throng' seminars for the great unwashed than the ones for the people who have been paying in since 1956 ......rant finishes:laughing:


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## gilbequick (Oct 6, 2007)

Wow, just reading that makes me dizzy. My how different the terms are from the UK to the US! 

What's a spur?


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## Trimix-leccy (Dec 4, 2007)

Spur either a {switched} fused connection unit to allow individual control / protection of an appliance off a ring main [or radial cicuit] OR a radial cicuit tapped off a ring main OR radial circuit sometimes gets called a spur just to make thing awkward:whistling2: so in theorey you could have a spur on a spur:laughing: 

.....and my daughter did not make the Team either:no: so I am now on a downer


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## frank (Feb 6, 2007)

Glad I don't install in residential/domestic anymore. You can't beat the simple life. By and large the Regs covered in Industrial are covered in one simple sentence - 'non standard circuit'. In other words . design anyway you want but do the calculations first.

Frank


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## Trimix-leccy (Dec 4, 2007)

Just got a letter from the NIC. My free seminar is next tuesday. So I will report back and start a new thread, should be funny. I once got banned from NIC seminars for being 'confrontational and asking awkward questions' 

I think I asked a question to which the NIC blokes answer was 'well, how long is a piece of string?' he then chuckled and tried to belittle me THIS WAS NOT A GOOD MOVE 

When I said that the piece of string in question was 'exactly twice as long as it was from its middle to one end' I received a round of applause, but not from him:thumbup: 

There are NO questions that are difficult, only the answers


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## cornishsparks (Oct 14, 2007)

*17th ed*

Im going to an NICIEC seminar in two weeks in a local 4 star hotel.appparently they did one in Plymouth not long ago and didnt even feed and water their delegates.
NAPIT would love me to join their crazy gang so i am blagging a free pass to a meeting next week that has a buffet.
No point going if you dont get **** all out of it.
Do what Frank does, dont do domestics stay awy from twat house holders that want it done for nothing.
If you fit MK non standard T pin sockets then that equipment is only for that socket and not portable, am i wrong?


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## Trimix-leccy (Dec 4, 2007)

I like your thinking on the T socket:thumbsup: 

But does it not come under the ...all circuits of 32A or less....yahda yahda yahda...rcd ....yahda yahda yahda? 

Good idea though


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## chrisb271 (Jul 6, 2007)

I think the midlands are having an NICEIC seminar shortly,i might go along and gatecrash just to heckle the host 
:devil2: :whistling2: :laughing: 

I decided to get away from domestics when the ODPM came up with the delightful idea of Part P,what a load of sh*t ! Good old two fat jags prescott,what a prize tw^t ! 

I will always remember when it had just come into force and i had " The inspector " round from the local council,he was all of twelve and still very wet behind the ears,he quoted me some stuff from a book,infact everything was read out the book,he spouted on about this was the way it was going to be from now on.
Well i had to get the soap box out didnt i :laughing: 

"40 odd years in the trade blah blah before you were born blah blah time served apprentice blah blah insult to my intelligence blah etc ,i think i ended up boring the lad into submission and he went away :laughing: 


I was disgusted with the whole thing at the time but now realise what a complete joke it all is,lots of the local contractors here are " REGISTERED INSTALLERS " Sh*t WoW ! all cutting each others throats for a crabby kitchen or bathroom install and for all that hassle you get to have a nice niceic sticker on your van of a house , well wooooopey f ' ing doooo.

Still if thats what floats your boat !

Chris


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## Trimix-leccy (Dec 4, 2007)

Couldn't agree more:thumbsup: 

We do very few domestics because of the reasons you state. The ones that we do do are for some very good clients. You know the sort, 'we are off to the villa in .........If you get chance while we are away can you....here are the keys, you know where the brew stuff is' and they pay straight away, no hassle. Few and far between I know 

Mainly commercial, Data, Telecomms, Fibre etc. nowadays. cleaner...more bunce...nicer work. Shop refits are quite good, also a lot of factory maintenance. But Domestics....PITA !!


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## cornishsparks (Oct 14, 2007)

The thing with Domestics is that when you tell the customer something lke they need their voltage operated trip replaced with an RCD.you see the look on their face change knowing they where watching last nights "rogue traders or house of horrors" . We all get tarred eith the same brush.
Only do new build domestics but only for one long time developer mate.
Dont bother with the odd domestic job only do commercial and industrial mainly.


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## [email protected] (Feb 8, 2008)

meggerman said:


> Just a quick hello to all the other forum members out there. This is my first time on this forum and I think it is a great way of sharing views on various electrical related subjects. I'm sure we've all come accross certain scenarios in the electrical field where the OSG or BS7671 is not always that clear. Here are 2 (for now...):
> 
> 1: In the OSG it is mentioned that with general earthing you use up to and equal to 16mm the same size cpc as the phase condutor. Then from 35mm and up you use half of the phase conductor size. When wiring with singles you usually use the same cpc and phase sizes. Why then can we use twin and earth with a reduced cpc to wire circuits?
> 
> ...


Hi,is the first time that im talk in the forum bicause I'm not now inglish very well sorry if mistake.
Im electrician in Italy and i'm plesure to learn how to work in hother country
In bathroom the aspirator in ITALY when only the bathroom withot windows


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