**CU Changes And YOU**

[oldtimer]

Just to sober everyone up here in Glasgow today a Sherif found a "handyman" at fault for the death of a 21 month old toddler after the child put a "disconnected" oven supply cable in his mouth so heres the deal as far as I am concerned this forum is not a pi&&ing contest its for electricians to help each other out and yes there is some old heads like me are big on safety so when advice is given the person asking it needs to realise the they are tapping into a wealth of knowledge yes I know that sometimes advice can sound condisending but remember this is not a game people can and do die with house electrics and over the years every apprentice I have had I have said "do you trust me when I tell you its isolated ?" and when I get the "O yes" reply I tell them wrong answer I add you are your own safety man so the answer I want to hear is "well fine but I will still be checking it" and far from being insulted when they question me I am pleased hence why I am still alive today

So do not take it the wrong way if you are questioned about how you are doing something because its not a personal attack but more of a concerned individual wanting to make sure things are done correctly remember we get posts on this forum daily from people who may want to cut corners or have a pretty neat idea how to do something and sometimes they will say "But why not" and thats fine but at the end of the day we are not reinventing the wheel

 

[Ohmyword]

Just to sober everyone up here in Glasgow today a Sherif found a "handyman" at fault for the death of a 21 month old toddler after the child put a "disconnected" oven supply cable in his mouth so heres the deal as far as I am concerned this forum is not a pi&&ing contest its for electricians to help each other out and yes there is some old heads like me are big on safety so when advice is given the person asking it needs to realise the they are tapping into a wealth of knowledge yes I know that sometimes advice can sound condisending but remember this is not a game people can and do die with house electrics and over the years every apprentice I have had I have said "do you trust me when I tell you its isolated ?" and when I get the "O yes" reply I tell them wrong answer I add you are your own safety man so the answer I want to hear is "well fine but I will still be checking it" and far from being insulted when they question me I am pleased hence why I am still alive today

So do not take it the wrong way if you are questioned about how you are doing something because its not a personal attack but more of a concerned individual wanting to make sure things are done correctly remember we get posts on this forum daily from people who may want to cut corners or have a pretty neat idea how to do something and sometimes they will say "But why not" and thats fine but at the end of the day we are not reinventing the wheel

A man after my own heart!
I tend to follow the quote of "wrong answer" with a clip round the earole just to make it certain that the message has sunk in ;-)
They can't (and mustn't) rely on ANYBODY in our trade. They MUST learn to take responsibility for their own safety in this game.

 

[impecc]

Sorry if this has been answered before. If changing a CU with 100A double pole isolator, are you saying that is not composory to compel the DNO to change the tail to 25mm2 and supply earth to 16mm2?

 

[truckster]

Sorry if this has been answered before. If changing a CU with 100A double pole isolator, are you saying that is not composory to compel the DNO to change the tail to 25mm2 and supply earth to 16mm2?

The size of the isolator is not the determining factor but the size of the fuse in the cut-out. Nominally these are 100A whilst in reality they are more likely to be 80A or even 60A. The 25mm tails debate has been stirred by the OSG stating tails should match the nominal rating. The DNO's are usually happy with 16mm as they know they will only supply an 80A fuse.If you are concerned about it you need to get a definite answer from the DNO in question.

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

 

[pete433]

Hi

The correct procedure should be as follows:

1 - Periodic inspection & test
2 - Remedials works repaired
3 - Fuse board can then be changed as the house will be to regs
4 - Final testing and electrical installation certificate issued.

 

[malcolmsanford]

Hi

The correct procedure should be as follows:

1 - Periodic inspection & test
2 - Remedials works repaired
3 - Fuse board can then be changed as the house will be to regs
4 - Final testing and electrical installation certificate issued.

Welcome to the forum but though a good practice not every client will pay for a PIR, and certainly on a CU change only what remedials would you expect?

What if the house installation does not have a lighting CPC, This would contravene regulation 412.2.3.2, so would you not continue with the CU change.

 

[pete433]

When a conumer unit is replaced the electrical contractor is responsible for all circuits that are distributed from it, if a lighting circuit has no CPC with class I fittings then the consumer unit should not be replaced as you are leaving the installation in a dangerous condition, unless you are willing to replace all fittings to class II and note on the fuseboard and certificate there is no earth you should not go ahead. If a periodic is undertaken first, all issues will be found, this is a transparent way of working for you and the customer.

Remember that this is standard practice, also remember that you cannot issue an electrical installation certificate with faults applied to it.

 

[nikmet]

pete, what sort of average price are you ending up at after carrying out a cu change, pir and repairs to 'standard practice' and how many hours on average do you spend without taking any faults into account?

 

[pete433]

The regulations are there to be adhered to, I have found over the years that if you give customers the right information and inform them of the correct format for a consumer unit change probably over 90% will apreciate the information and we will gain the contract. Some installs after the PIR can be a few hours work others a few days for remedial, are main concern is that the property is to regulations and that the installation certificate will hold up to regulations. The days of just slapping a consumer unit in are long gone and rightfully so. All of the relevant bodies will back-up the pir,remedial,ccu change, test procedure.

 

[nikmet]

The regulations are there to be adhered to, I have found over the years that if you give customers the right information and inform them of the correct format for a consumer unit change probably over 90% will apreciate the information and we will gain the contract. Some installs after the PIR can be a few hours work others a few days for remedial, are main concern is that the property is to regulations and that the installation certificate will hold up to regulations. The days of just slapping a consumer unit in are long gone and rightfully so. All of the relevant bodies will back-up the pir,remedial,ccu change, test procedure.

I agree 100% with what you are saying, i was just genuinely interested as to how many hours for, pir, cu change, final testing, completing certificates, I am constantly hearing of sparks doing cu change in 4hours complete, (2 a day) and I think this is impossible to do it correctly in 4 hours?

 

[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