**CU Changes And YOU**

[pete433]

The Pir will vary but we would look at around a day to complete the inspection with the paperwork (easycert). After PIR we will explain the issues found and produce an estimate for repair.

The consumer unit change will take around a day this includes overall install and testing.

I agree I heard of a sparks who undertook four inspection and tests in a day including completion of paperwork, he must of run around and missed a lot!!!!

 

[malcolmsanford]

You still have not really answered my question concerning 412.2.3.2. Yes you are correct that no class I type of equipment should be use, but the reg clearly states that a CPC must be at every point of the circuit that supplies one or more Class II items of equipment.

Your opening statement that by doing your PIR and remedials, which will leave the installation conforming to the regs is perhaps not quite correct, unless for every non CPC lighting circuit you encounter you advise the client that it must be re-wired to conform to the current regulations, which IMO is a money making scheme, as the regulation are not retrospective.

I would be most miffed if you changed my CU change and then extraed me for fitting over sleeving on switch lines, over sleeving on bare CPCs, as you picked that up on your PIR and as it now fails the current Regs it should be redressed.

A PIR is not done to ensure that the existing installation is to the current regs, it is done to ascertain the conditgion and continuing use of the installation.

 

[pete433]

As per your last comment about the PIR the penny has hopefully dropped, you test the installation to ascertain the condition of the property, you then are required to bring the property up to BS7671 before a consumer unit is installed, then on completion an eletrical installation certificate is issued. There are a few caviates as explained in the ECA with regards to CPC and lighting, we as a company will not replace a fuse board if any circuits are missing an earth. Also it is good practice to check all connections and denotation of switch wires can be undertaken whilst doing this, good luck.

If you as a company choose to install a CU without an earth to lights the below reg in extreme circumstances can be used

Regulation 412.1.3, where, under the strict conditions imposed by that regulation, Class II or equivalent insulation is used as the sole means of protection against indirect contact for a whole installation or circuit.

 

[malcolmsanford]

So you do not as a whole change a CU unless the lighting circuit is upgraded to have a CPC?

Your work as to conform to BS 7671-2008 and your work is a CU change, not the existing installation. How do you know even after an a thorough PIR that there is not an un-accessible junction box under the floor or even buried in a wall? Are you going to start to dismantle everything to ensure before you change that CU the installation is now compliant in every detail.

So if an entire house on your CU change did not have sleeving you are quite prepared FOC to undo every connection to every appliance that required sleeving?

Your CU change is just that a CU change unless every customer you deal with is totally prepared to pay for perhaps 2-3 days labour cost, for bringing the existing installation upto the current standards, then your remit is to ensure that the alteration to the installation will not adversly effect it, I would be interested to see you post the relevant Regs that insist that an existing installation as to be upgraded to the existing BS standard before any alteration or addition can be done.

 

[Chr!s]

Pete 433

Please try link :http://www.esc.org.uk/industry/industry-guidance/best-practice-guides/

Read Guide 1 and 6 these may help.

Regards Chris

 

[High Tower]

Havent read the whole thread, but here is what i do,

Group L&N from upper lighting circuit, gropu the same for the lower, and test to 250v IR test, this usually shows any borrowed neutrals

 

[pete433]

5.3. However, circuits that are defective or noncompliant
with the requirements of BS 7671 in a
way that would result in real and immediate danger
must not be connected to the consumer unit.

How could you adhere to this regulation without inspection!!!! You can obviously can do an insulation test visually!!! Or do you just wait for the RCD to trip and then talk to the customer.

 

[Octopus]

"The is no legal requirement, and no regulation in BS 7671, requiring an existing installation to be upgraded to current standards"

Extract from Snags and Solutions Part 3 - Inspecting and testing from the NICEIC. (a book I would recommend that all new/recent qualifiers buy and read -its about £15.00 delivered and full of useful tips).

 

[malcolmsanford]

5.3. However, circuits that are defective or noncompliant
with the requirements of BS 7671 in a
way that would result in real and immediate danger
must not be connected to the consumer unit.

How could you adhere to this regulation without inspection!!!! You can obviously can do an insulation test visually!!! Or do you just wait for the RCD to trip and then talk to the customer.

Testing a circuit is completely different to carrying out a PIR. No one in here is disputing the fact that on a CU change your more than likely changing the characteristics of the protection and therefore you need to issue a EIC.

An EIC does not require you to carry out a full PIR on the existing installation, and it does not need to be upgraded to the current regs, it as simple as, this is now 3 of us telling you this.

So I assume you are considering that a lighting circuit that does not have a CPC and does not have any class I equipment fixed, is presenting a real and imidiate danger?

 

[pete433]

If you all can honestly say that the correct course of action is just to replace a consumer unit without prior inspection then good luck for the future, this is why the buisness i own is currently as always expanding as it has for the last fifteen years. The one man bands i can see have to make a living and not offering the correct solution to allow there property to be adherent and most of all safe for the future is a choice for your buisnesses. We offer a package that updates properties to regs we will not leave properties with faults that in the future could be an issue.

Strive to offer a quality solution is my advice and your buisnesses will move in the right direction, a full IEC makes you liable for all circuits after install. All the major electrical bodies will advise an inspection before CCU change, call them and they will confirm this.

 

[Ohmyword]

My 82 yr. old Mother has recently had a "walk-in shower" installed in her bathroom. If I can give you all the background info.; her place is an end of terrace, small, two-bed, "Wimpey" type building. (Purpose built estate of cheap, family housing).
It has a Wylex 604N consumer unit (therefor re-wirables and 60/80 Amp main switch) on 16.0m.m. tails and 10.0m.m. main earthing cables.
A 6.0m.m. T&E had been wired from this unit for a shower point at some time after original installation. This circuit was protected by a 40Amp circuit breaker within the 604N.
She was able to "get a grant" to have the shower room altered.
The "body" that arranged everything, use "their registered" contractors.
The firm that carried out the work "brought in" their own NICEIC contractor.
There were three circuits in the shower room; lighting, heater & shower.
I queried some of the decisions made and work carried out, but because, in theory, my Mother was not "the employer", there was little I could do.
They re-used the 6.0m.m. T&E for the new 9.5Kw shower unit. (It was only a 10/12mt length). They left the 604N consumer unit exactly as it was, but to "get over" the "every circuit in a bathroom should have 30mA RCD protection" recommendation, they installed a 80Amp-30mA RCD as the main incomer/isolator between meter and 604N.
I can only assume that the electrician provided his certificate for the shower room, with his test results, to the "builder" who would have passed this on to the "body" that arranged the grant monies?
This surely does not allow for the fact that if there is ANY problem with ANY circuit, it will "take out" the whole house electrics?

 

[Octopus]

My 82 yr. old Mother has recently had a "walk-in shower" installed in her bathroom. If I can give you all the background info.; her place is an end of terrace, small, two-bed, "Wimpey" type building. (Purpose built estate of cheap, family housing).
It has a Wylex 604N consumer unit (therefor re-wirables and 60/80 Amp main switch) on 16.0m.m. tails and 10.0m.m. main earthing cables.
A 6.0m.m. T&E had been wired from this unit for a shower point at some time after original installation. This circuit was protected by a 40Amp circuit breaker within the 604N.
She was able to "get a grant" to have the shower room altered.
The "body" that arranged everything, use "their registered" contractors.
The firm that carried out the work "brought in" their own NICEIC contractor.
There were three circuits in the shower room; lighting, heater & shower.
I queried some of the decisions made and work carried out, but because, in theory, my Mother was not "the employer", there was little I could do.
They re-used the 6.0m.m. T&E for the new 9.5Kw shower unit. (It was only a 10/12mt length). They left the 604N consumer unit exactly as it was, but to "get over" the "every circuit in a bathroom should have 30mA RCD protection" recommendation, they installed a 80Amp-30mA RCD as the main incomer/isolator between meter and 604N.
I can only assume that the electrician provided his certificate for the shower room, with his test results, to the "builder" who would have passed this on to the "body" that arranged the grant monies?
This surely does not allow for the fact that if there is ANY problem with ANY circuit, it will "take out" the whole house electrics?

Maybe you should have started a new thread with this.

40A and 6mm is probably OK, but the final decision would be based on seeing the "run" of the cable.

As for a single RCD now protecting the whole house - I wouldn't have done that.

 

[telectrix]

cheapskates. should have fitted a new CU.

 

[Ohmyword]

Maybe you should have started a new thread with this.

40A and 6mm is probably OK, but the final decision would be based on seeing the "run" of the cable.

As for a single RCD now protecting the whole house - I wouldn't have done that.

I posted on this thread because I too would have changed the consumer unit and wanted to hear other comments. Is what I have described, common NICEIC practise?

The other circuits in this Wylex 604N (two feeding circuits in the shower room) are still on re-wirable fuses.

Should they have installed a 17th edition, high integrity unit?

I would also have upgraded the 6.0 m.m. (on shower) to 10.0 m.m. (just as a "in case the shower is ever upgraded" reason).

 

[malcolmsanford]

The existing circuits in the bathroom which I believe you said were lights and heating, as long as they never worked on them then as per the 17th BS 7671-2008, they have no need to RCD protect them, though with a elderly customer I would have advised that.

As for the work that was done which was repalcing the old shower with that new 9.5KW. That at 240volts which most showers are rated to gives you 39.6 amps. The only way that 6mm cable will be sufficient is if it is clipped on the surface, is it??

As for the single 80amp up front RCD well IMO that contravenes regulation 314.1 Division of installation and should not have been done.

If I were you after checking the cable run for the shower and if any of the cable goes through a wall or is buried or is in trunking, then a strong letter to the body should be sent, highlighting the issues i've raised, I would be pleased to help you draft this letter, quoting relevant Regs to get this circuit and installation done to the standards and safety your mother deserves.

While your checking the cable also see if there is a Yellow/Green cable attached to the main water pipe and if she as it the main gas pipe, and is it the same size as the main earth cable. We will touch on the chance of it being plastic or not later.

Also as it was a shower circuit, are all the pipes in the bathroom have green/yellow cables, again we will cover the part about them being extraneous conductive parts later.

 

[Spudnik]

Hmmmm yes, division of circuits should have been thought about, however, if a client is not prepared to pay additional costs for the installation of a new CU, i dont see any reason any a 30mA RCD upfront cant be used.

Normally in these situations i install a stand alone CU with 30Ma RCD MS and swap the new circuits and any worked on, to it.

Tin hat on

 

[malcolmsanford]

Hmmmm yes, division of circuits should have been thought about, however, if a client is not prepared to pay additional costs for the installation of a new CU, i dont see any reason any a 30mA RCD upfront cant be used.

Normally in these situations i install a stand alone CU with 30Ma RCD MS and swap the new circuits and any worked on, to it.

Tin hat on

That is exactly what I would have done Jas, either henley blocked the tails, or if the existing board was rated for it, removed the Shower circuit from it, and fed a new shower board from the way in the CU and diverted the shower circuit into the new RCD/RCBO one. But fitting an up front RCD that if there is any fault within the installation,would leave an 82 yr old woman without heating, lighting or any power is just plain crazy IMO

 

[jonesyc894]

is it ok for me to pull main fuse to accomplish this i know supplier should but as the seals are missing anyway would i get away with this

Just take out the main fuse and if questioned IF. Tell them you had to perform an emergency isolation.

 

[wade88]

Quick Q,

Under what circumstances are you obliged to upgrade the tails of a CU? Apart from the obvious such as they are too small.

 

[Des 56]

If they are "buried less than" etc where an Rcd would then have to be employed and discrimination issues with the consumer unit Rcds become a problem

 

[BP Electrics]

The tails and earthing conductor are the customers/your responsibility, the DNO's won't change them.

I recently completed a 1st fix re-wire where as part of the job I had changed some dusty old 10mm tails for a nice new set of 25mm brown and blues. In between then and returning for the 2nd fix, the DNO had sent an engineer to upgrade the meter. To my surprise, I returned to find my new shiny copper tails had disappeared, only to have been replaced by a pair of red and black 16mm tails supplying from a BS88 100A fuse.

 

[Des 56]

Out of interest
Is that the tails between the meter and cut out,or between the meter and your consumer unit ?

 

[BP Electrics]

They were from a Henley block bridging between the meter into the new CU.

 

[Ohmyword]

I recently completed a 1st fix re-wire where as part of the job I had changed some dusty old 10mm tails for a nice new set of 25mm brown and blues. In between then and returning for the 2nd fix, the DNO had sent an engineer to upgrade the meter. To my surprise, I returned to find my new shiny copper tails had disappeared, only to have been replaced by a pair of red and black 16mm tails supplying from a BS88 100A fuse.

I've never known any DNO engineer to get anywhere near touching a consumer unit (they are not allowed to). I would even consider asking all who has access to this mains equipment if they know who has "nicked" your tails.

On the subject of 16.00mm or 25.00mm tails. The EDF engineers I "come across" here in West Cornwall will not use 25mm tails at all! (Only 16's) Regardless that I have installed 25's into my c/u.

 

[Octopus]

I recently completed a 1st fix re-wire where as part of the job I had changed some dusty old 10mm tails for a nice new set of 25mm brown and blues. In between then and returning for the 2nd fix, the DNO had sent an engineer to upgrade the meter. To my surprise, I returned to find my new shiny copper tails had disappeared, only to have been replaced by a pair of red and black 16mm tails supplying from a BS88 100A fuse.

Are you saying you changed the tails from the DNO fuse to the meter?

 

[Deleted member 26818]

Would using 16mm² tails instead of 25mm² limit the Ze to any apreciable amount?

 

[BP Electrics]

Are you saying you changed the tails from the DNO fuse to the meter?

No Sir, correct me if I'm wrong, but I am of the opinion that everything up to the distributor's meter is within their own jurisdiction? The tails I'm referring to were connected directly into the CU main switch via a Henley block. I was a tad perplexed as to why they changed them, but never chased it up as I got very drunk that night and forgot about it until now.

 

[daiplayer]

perform an IR test between the earth an neutral bar (ensure the main earthing conductor has been disconnected)

this is likely to be done so that when you install RCD's or RCBO's with your new CU then your not likely to get any nasty susrprises with the RCD's tripping all the time due to a previous issue that is irrelelevant to your new CU change

Never knew that !!!! ?? ...how come it dont damage anything then ?

 

[Spudnik]

Because you should test at 250V and in theory the two should not be connected.

 

[RobMax]

Very useful info

 

[Boberto]

Really interesting thread. There is alot of mixed opinion on what you are responsible for with regards CU changes/upgrades.

I would be interested to know peoples opinions on the following scenario...

What if you carry out a CU change and there is a N-E fault that causes the RCD to trip. The fault is on the downstairs ring but due to the way it was wired years ago (not a perfect ring), lots of additions and spurs, possible interconnections, junction box minefield - it is not easy to pinpoint the damaged leg of cable just by splitting the ring etc without taking up floor boards and tracing the cables. You manage to narrow it down to the kitchen which was wired by a kitchen fitter when the kitchen was done 12 months ago. Cables buried. The RCD holds when two kitchen sockets are dead/removed from the ring so it seems the fault is a cable spurring to these from the ring final.
You explain to the customer the fault, remind her that you did say there would be fault finding work as you carried out some pre board change IR tests. Customer isnt happy that 2 sockets dont work in her kitchen, nor is she keen to have a new cable installed to over come the problem. Her kitchen is nice and new and those sockets were working fine before I installed the new board. She doesnt want trunking or walls chased to install a replacement cable. You remind her that you are working to regs and that she agreed to the board change because it complys and makes the whole installation a lot safer.

I have read in this thread of fellow sparks saying that in the long run they have improved the safety of the overall installation by upgrading the CU. The individual wiring of every circuit does not become their responsibility. All the other circuits in this scenario are now RCD protected. The fault remains on the ring but the customer doesnt want her two kitchen sockets left out of service, regs or no regs. In order to keep the customer happy and get paid, how would you resolve the situation?

 

[Deleted member 26818]

The simplest method would be to remove the RCD protection.

 

[Boberto]

Agreed. But is it acceptable to notify the customer that the ring would therefore not be RCD protected, configure the CU, leave the ring unprotected and make a note on the certificate of the fault, reason for outcome and advise the fault needs to be rectified in the near future??

 

[Ohmyword]

Well Boberto, it's probably not what you want to hear, but, 'horse, stable door & bolt' comes to mind!
I have been 'caught' in this situation myself on more than one occasion, therefor I carry out some 'basic prelimary' tests before completely dismantling and removing the existing consumer unit(s).
If one discovers any 'problems' that cannot be easily overcomed, or the customer is not in agreement with the possible extent of the work and/or price involved, then one can walk away from the job. You can make a report and statement that you had provided the householder with all the relevant information (and report) and quote for the remedial works needed, but they had declined.

I'm sorry that this doesn't help you with your current problem, but it could be the way for the future?

 

[Octopus]

Agreed. But is it acceptable to notify the customer that the ring would therefore not be RCD protected, configure the CU, leave the ring unprotected and make a note on the certificate of the fault, reason for outcome and advise the fault needs to be rectified in the near future??

How about asking your customer to see the certificate that the kitchen fitters gave her?

 

[Boberto]

Just to clarify. Its not a situation I am in now. I experienced it in the past. Just wondering what your opinions were and where we stand as competent people if we were to leave the Ring unprotected on the new board?

 

[Boberto]

Murdoch, from memory there was no certificate. Surprisingly.

 

[malcolmsanford]

To be honest most sparks now, after the extensive use of RCDs in domestic installation will not, or should not be faced with this now. I'm sure in the beginning a few sparks were caught out like this but now we are 4 yrs down the line with extensive RCD protection, and most guys will test for this as was posted above.

But for your hypothetical question I think I would split the ring into radials, and give the at least one of those radials RCD protection, and the other one would be marked down on the EIC under "comments on existing installation" and quote the reg your deviating from and leave it on it's own. I would prove though that it did disconnect within the 0.4secs by doing the Zs and that would be me.

 

[BP Electrics]

To be honest most sparks now, after the extensive use of RCDs in domestic installation will not, or should not be faced with this now. I'm sure in the beginning a few sparks were caught out like this but now we are 4 yrs down the line with extensive RCD protection, and most guys will test for this as was posted above.

But for your hypothetical question I think I would split the ring into radials, and give the at least one of those radials RCD protection, and the other one would be marked down on the EIC under "comments on existing installation" and quote the reg your deviating from and leave it on it's own. I would prove though that it did disconnect within the 0.4secs by doing the Zs and that would be me.

+1 to this solution.

Historically, whenever my pre-change IR tests have shown poor results and I advise the client, they usually think I'm making up crap just to bloat the quote, and the job gets lost. I should brush up on my people skills...

 

[Ohmyword]

+1 to this solution.

Historically, whenever my pre-change IR tests have shown poor results and I advise the client, they usually think I'm making up crap just to bloat the quote, and the job gets lost. I should brush up on my people skills...

Tell them to get a 2nd opinion. Better that, even if you lose the job, than creating an 'enemy'.
You know how the saying goes? "Do a good job and 5 people hear about it! Do a bad job and 50 people hear about it!" ;-)

 

[Snapester]

When you guys go around to see a CU change and you carry out the test to check the installation before quoting work, do you have the customer disconnect all appliances when doing the IR tests checking for connections between L+N, as i have had problems with shorts showing on circuits because of certain items plugged in?

 

[robsparky1975]

Must be things plugged in somewhere perhaps L&N - E would be a good option here,ive had a borrowed neutral circuit recently on a board upgrade.

 

[Snapester]

Yeah, we'll checking for borrowed neutrals is easy enough but checking interconnections on ring finals with IR tests and get bad readings from plugged in items! Is a ball ache, and asking customer to unplug everything is equally a ballache! But in long run could save hrs!

- - - Updated - - -

Yeah, we'll checking for borrowed neutrals is easy enough but checking interconnections on ring finals with IR tests and get bad readings from plugged in items! Is a ball ache, and asking customer to unplug everything is equally a ballache! But in long run could save hrs!

 

[Poorle]

Hi Jason,

Thanks for the information on CU changes. I have been asked by a mate to look at his electrics. Situation is: a CU has been moved and was hanging off the wall, all circuits bar the boiler circuits removed. Flat been renovated and all cables from the existing circuits cut and left sticking out the floor boards. Owner wants all cables extended and put back into the existing CU - which has no RCDs on it. Flat has been plastered / painted and he doesn't want any damage to plasterboard or paintwork.

Would you extend these cables in junction boxes?

Would you recommend a new CU? - this one doesn't have RCD protection on any of the circuits...

 

[Octopus]

Hi Jason,

Thanks for the information on CU changes. I have been asked by a mate to look at his electrics. Situation is: a CU has been moved and was hanging off the wall, all circuits bar the boiler circuits removed. Flat been renovated and all cables from the existing circuits cut and left sticking out the floor boards. Owner wants all cables extended and put back into the existing CU - which has no RCDs on it. Flat has been plastered / painted and he doesn't want any damage to plasterboard or paintwork.

Would you extend these cables in junction boxes?

Would you recommend a new CU? - this one doesn't have RCD protection on any of the circuits...

New CU is the only way and how many cables need extending?

 

[Pete999]

Good advice many thanks

 

[Poorle]

New CU is the only way and how many cables need extending?

Thanks. All existing circuits need to be extended (around 12 cables). The cables have been cut off, none are labelled up so it's difficult to check what cables are for what circuit.

To check for a ring circuit I tried pairing up the cables one at a time and checking for continuity between lives but found none. Bit stuck..

 

[robsparky1975]

In this instance i would take a socket off for instance and do a backward continuity test,so R1 & R2 test back to the board just to help indentify or indicate circuit/s.Have had to do simliar,didnt take much longer than a standard test anyway as i dont take whats written on old boards as gospel only an indication of what it may or may not supply.Having a helping hand to do the running about would cut the time down a bit.

 

[bigbob]

Always done a full EIC stating that no new circuits or points have been installed, test results given for existing circuits are for information only.
I was told a couple of years ago by my area engineer that this was wrong, and i should not include test results for circuits I had not installed.
The next year the same area engineer asked why I had not included test results on an EIC and advised to take a look at the ESC guidance notes. I had also issued a full PIR, as not fully testing the existing install just feels wrong.

 

[Poorle]

In this instance i would take a socket off for instance and do a backward continuity test,so R1 & R2 test back to the board just to help indentify or indicate circuit/s.Have had to do simliar,didnt take much longer than a standard test anyway as i dont take whats written on old boards as gospel only an indication of what it may or may not supply.Having a helping hand to do the running about would cut the time down a bit.

Thanks, i did that and got readings of between 0.85 - 2.75ohms on all sockets connected to that ring -which is pretty high don't you think? Might be time to calibrate the fluke i bought recently!