Ze too high

[kme]

Are you suggesting that selecting a 100mA RCD would not comply with 5431.2.4?

100mA specifically? no. But one RCD at the origin - debatable.

Do you believe that there is likely to be more than 100mA protective conductor curent during normal operation?Are you suggesting perhaps a 300mA RCD be installed?

Pardon? OH! can you post reg.5431 for me? My BRB doesn`t seem to have that one........

As far as I'm aware, there is no intention to install any socket-outlets.As such the lack of compliance with 411.3.3(i) should be noted on the certificate under comments on the existing installation.

415.1.1 refers to the provision of additional protection.

I am not aware that provision of earth fault protection is classed as additional.

No? Read words 10 through 15 on the third (last) line of that reg.

Yes socket-outlets, circuits of special locations and cables concealed in walls etc. will require 30mA RCD protection.As none of these are being installed, they are existing, the lack of such protection should be noted as per the requirement of Regulation 633.2.

BUT

The earthing of the installation is being altered from TN to TT - Do you really believe that "leaving the install in no worse condition than it was" can be assuaged by installing 100mA in the tails?

Sorry mate -I`d consider that bad practice at best, at worst its negligence IMO.

KME

 

[spinlondon]

Steps please go away and read BS7671.

There is no requirement for you or anyone to upgrade existing installations.

I would not consider that providing earth fault protection for an installation where there is none at present as changing the means of protection.

Installing a 100mA RCD is not outside of BS7671/2008, I have already provided you with the Regulation No. that requires it.

It is not a departure, it is a compliance.

Again read the Regulations, and stop wasting your time making insults. All you are doing is proving just how ignorant you are.

 

[Manator]

Debate without personal insults and the debate will be allowed to run. Otherwise I and any other moderator will close or delete posts, so those who wish to debate can do so.

 

[kme]

Sorry. :coat

I`m outta here.

`night all

 

[Manator]

Thread now closed.

 

[soulman]

hi i dont want to open a can of worms im just finishing my third year so still learning be gentle:|. i was enjoying larkysparkys thread but it reached no conclusion. In those circumstances where there was a poor connection or no connection to earth. i would have put in a rod and a upfront 30ma rcd after doing a quick insulation resistance test LN to E as a temporary measure until a new consumer unit was purchased and noted on the cert would this be the correct procedure as if you put a rod in and no rcd protection would that be potentially lethal?

2, if during an insulation test you found faults that could not be easily rectified would you still do above but leave those circuits disconnected?

 

[PC Electrics]

Yes, shame it got closed, I was hoping to make a contribution this morning.

---------- Post Auto-Merged at 12:11 ---------- Previous post was made at 12:03 ----------

hi i dont want to open a can of worms im just finishing my third year so still learning be gentle:|. i was enjoying larkysparkys thread but it reached no conclusion. In those circumstances where there was a poor connection or no connection to earth. i would have put in a rod and a upfront 30ma rcd after doing a quick insulation resistance test LN to E as a temporary measure (1) until a new consumer unit was purchased (2) and noted on the cert would this be the correct procedure as if you put a rod in and no rcd protection would that be potentially lethal?2, if during an insulation test you found faults that could not be easily rectified would you still do above but leave those circuits disconnected?

(1) does not comply with BS7671. One RCD covering the whole of an installation does not cut it. And as for "temporary" measures - NO - because once you've left the client will forget about the new CU 'cos it's working fine and I'm safe and anyway the kids need new shoes and the car needs an exhaust.............................

(2) This is the proper way to do it. At least a dual RCD board, assuming the existing board cannot be converted or RCBOs added.

Oh, and any RCD protection you add must comply with BS7671, ie any <20A sockets and bathrooms and buried cables must be provided with additional protection by a 30mA RCD, NOT a 100mA.

It is true that there is no legal or regulatory requirement to "upgrade" any installation (the [domestic] owner can leave it as dangerous as he likes), but once you do start working on it then the work must comply with BS7671:2008.

 

[Mr Smith]

mr electrics

the thread was closed due to the moderators being unwilling or unable

to monitor the thread throughout the night

as long as the discussion can be kept civil

i see no problem with re opening the thread

and merging mr mans thread

with the original one

however

if last nights unpleasantness reoccurs

we will have no other option than to close the thread again

gentlemen

it is in your hands

mr smith

 

[Sidewinder]

I think we should open it for the day and the last mod to bed tonight can close it again, just in case?...

 

[Manator]

Mr Smith has given a very good answer as to why the thread was closed. It is now open so those who are interested in this debate can take part, again I would remind all who post to stay friendly as this forum is built on that and other great attributes.

 

[gordy71]

SW , I would have agreed with that up until a few years ago,up until then anytime I had ever rang DNO about a high earth they have been out within an hour at most,

then on one occasion they came out, ****ed about for an hour or so, got the earth to 0.7 and issued the householder with a notice serving disconnection of earth after 14 days,

dunno what it was all about but tenant apparently sought advice on it and anyway we were back the following week to TT it.

Why did they want to disconnect the earth when they managed to get it down to an acceptable reading? Sure it is still higher than you might want and you may struggle to get acceptable zs readings on some circuits but doesnt make sense to me? Could you just leave the tns in place and tt it as well as a backup or is this a nono?

 

[steptoe]

Why did they want to disconnect the earth when they managed to get it down to an acceptable reading? Sure it is still higher than you might want and you may struggle to get acceptable zs readings on some circuits but doesnt make sense to me? Could you just leave the tns in place and tt it as well as a backup or is this a nono?

most likely a case of they bodged an earth from somewhere,

perhaps by temp linking the neutral in or rodding it somewhere, or they simply didnt want to be responsible if the earth dropped out again,

either way, it no longer left the caveat on them to have any responsibility once they had served the notice of disconnection I suppose.

 

[SLIPSHOD & SLAPDASH]

How do they intend to withdraw the earth connection after 14 days ? I doubt they will return & its just a get out for any time in the future there may be a problem.

 

[steptoe]

How do they intend to withdraw the earth connection after 14 days ? I doubt they will return & its just a get out for any time in the future there may be a problem.

i said the exact same at the time.

just a way of negating their responsibility.

 

[LarkySparky]

Hey Guys, thanks for the replies and advice.

DNO is not helpful and basically wants nothing more to do with the situation-

quote: " well there was never an earth to the property in the first place so a mains upgrade will be needed and the installation will be made TNC-S "

So why do you have it down as a TNS then?? Does that not mean a separate incoming earth?? MAINTAINED!!!!!! (Be it the armouring or the like) anyway, sigh, bar a