Tests associated with new C-U install

[STEVEROG]

What are considered to be the minimum tests that should be carried out when a new C-U is installed?

How do these tests compare to those needed for a periodic inspection (or whatever this is called these days)

 

[JohnW2]

What are considered to be the minimum tests that should be carried out when a new C-U is installed? How do these tests compare to those needed for a periodic inspection (or whatever this is called these days)

I think many would probably suggest that an Electrical Installation Condition Report ('EICR' - that's what PIRs are now called!) should be undertaken before a CU is replaced.

Kind Regards, John

 

[ericmark]

In the main corners are cut other wise it would take longer to test than do the job but most people get a feel for what needs testing.

For example before I start if there are two fuses for the lights I remove one and test two way lights in case supply taken from two fuses for one lamp.

Insulation test is a must last thing you want if after fitting to be running around looking for earth faults before you can set the RCD.

When fitting a consumer unit you are really taking over responsibility for the wiring unless you point out the faults. There are two conflicting rules first is you should not leave the house in a dangerous condition and second is you must not make a house uninhabitable without making alternative arrangements for the occupants.

So you need to be aware of all faults before you start so your not going to have to argue or foot any bills for faults which only come to light after the change.

The Electrical Safety Council has issued guide lines about what to do if for example you find the lights have no earth wires. Personally since there should have been 5 PIR/EICR since the rules changed in the 1960's I think it's time to say enough is enough but others feel that adding a RCD has to help and to refuse to change a CU means more not less danger so it should be changed even if the wiring is not to current regulations.

However this is a watch your back era so any faults need careful documenting so you can show any court you made the owners aware of any faults.

I would read Electrical Safety First Best Practice Guide No. 6 (Issue 2) then re-ask on any points your not clear on.

Although I don't agree with all they say if something goes wrong and you can point to the guide and say I followed the advice given in the guide likely you will not be held responsible.

 

[swampy2]

I now put my clamp meter on earth leakage setting and fit onto main earth, then turn on heavy duty appliances.

 

[PrenticeBoyofDerry]

What are considered to be the minimum tests that should be carried out when a new C-U is installed?

How do these tests compare to those needed for a periodic inspection (or whatever this is called these days)

They will be the same!
There is no short-cut testing procedures when commissioning a new CU install.
First of all safe isolation, this may require the main fuse to be removed if it is an existing installation, note this fuse belongs to the DNO and permission will be required to have it removed.
The procedures known as CRIPPLER are then carried:
* Dead test:
C. continuity of earths including main and supplementary bonding.
R. continuity of ring final circuit.
I. insulation resistance.
P. polarity
* Live tests:
P. polarity of tails
L. loop impedance.
E. earth fault loop & earth spike (if a TT earth arrangement)
R. rcd functional tests.
Also functional test on outlets, switches and sockets etc...
There would also be a requirement for a schedule of inspection to be made, prior to testing.

 

[ericmark]

* Live tests:
E. earth fault loop & earth spike (if a TT earth arrangement)

I would have said this should be tested before power is turned on. To test an earth spike means disconnecting it and to have power on with spike disconnected is dangerous so this is a dead test.

OK use the DNO live to loop impedance meter where a proper earth rod meter is not available or impracticable but the power should be off to house when this is tested. Also of course the earth spike pit should be guarded during the test as dangerous voltages can be generated on the spike during the test.

Once all is live yes I would select the odd socket and re-test but again aware that the earth loop impedance testing can produce dangerous voltages during the test.

Where the lights don't have earths we are supposed to use stickers on the CU warning. However I question how far we should go with testing? Selecting a lamp close to the consumer unit on each lighting circuit we will test the earth. But if earth exists then to test every lamp is questionable. I have seen where out houses and sheds still have no earth to lights where house has been re-wired but not out building. This would need checking with full EICR but I would consider beyond the remit with simple CU change.

This is a personal point of view would like to see what others consider on this.

 

[STEVEROG]

Plenty of food for thought.

I guess its a straight choice for me then......

(a) Install the new CU myself (after of course obtaining permission to pull the main fuse) then get A periodic inspection done (as requested by BCO).


(b) Get a sparky in with the test and inspection qualification to do the CU installation AND the periodic inspection which as you've all pretty much pointed out, goes hand-in-hand with the CU install anyway.

Option 'b' is perhaps starting to look sensible given that the periodic inspection goes along with the CU installation anyway.

I think I'll get a couple of quotes from some local sparks and see what the cost looks like compared to inspection only. The only issue I then have is making sure I don't end up with an untidy CU wire-up. I've seen some pictures of tidy work on here, maybe one of those chaps with pride in their work lives local enough to me to do my C-U.....?

 

[PrenticeBoyofDerry]

(a) Install the new CU myself (after of course obtaining permission to pull the main fuse) then get A periodic inspection done (as requested by BCO).

You would need to notify the work prior to starting and pay the fee required in your area. Ideally an "electrical installation condition report" (EICR), would be best done before you even attempt to swap out, there might be every chance that a straight swap is not possible without extensive work to the existing system, also on completion of the install it is an "electrical installation certificate" (EIC), that needs to be issued.

(b) Get a sparky in with the test and inspection qualification to do the CU installation AND the periodic inspection which as you've all pretty much pointed out, goes hand-in-hand with the CU install anyway.

As above and EICR would be done prior to removal of existing unit, and remedial work that requires attention will be flagged up on this and dealt with prior to swap, on commissioning an EIC can then be issued. If the electrician is a member of a "competent persons scheme" then they can notify for you for a small charge, if they are not, then likely to be a hefty one, which again will need to be applied for and approved prior to work starting on replacing the existing unit.
And it is inspection and test not vice versa!

Option 'b' is perhaps starting to look sensible given that the periodic inspection goes along with the CU installation anyway.

Option 'b' is the wise option if you have little knowledge on inspection and testing and do not own the calibrated equipment needed to do the tests, plus there is always the notification fees that can be a deciding issue.

I think I'll get a couple of quotes from some local sparks and see what the cost looks like compared to inspection only. The only issue I then have is making sure I don't end up with an untidy CU wire-up. I've seen some pictures of tidy work on here, maybe one of those chaps with pride in their work lives local enough to me to do my C-U.....?

An inspection only will serve little purpose for what you propose, you require inspection, testing and certification.
I would go down the 3 quote route, word of mouth is always the best option when making a choice, recommend you ask if they can prove quality of work and have testimonies from clients. Also to avoid the additional procedure of having to apply prior to work starting and the often hefty notification fee, it would be worth using an electrician that is registered as competent. http://www.competentperson.co.uk/

 

[nickjb]

Plenty of food for thought.

(a) Install the new CU myself (after of course obtaining permission to pull the main fuse)

just add a bit more food for your thought... You might be able to get your supplier to fit an isolator switch. They fitted one for me for about £70. Means I could isolate to fit the new CU and attach the existing circuits then periodically isolate it again to add the new circuits when I was ready.

 

[ericmark]

The LABC as name suggests is local and the rules they work to vary county to county. In Liverpool my son had no problem doing work. In Chester a little more strict. In Flintshire it was really hard to get the inspector to accept what was being done.

So looking at the rule book only the guy would installs the installation can sign the installation certificate. Clearly there has to be some leeway when some one becomes ill or dies but where the person who installs can then he and only he will fill out the certificate.

So if you install then you inspect and test and fill out the installation certificate. The building inspector can then select parts to re-test to satisfy himself you have done it correctly. He can also lay down what qualifications you must have.

Liverpool was easy we did the job and the building inspector selected a few items and when the results matched he assumes you have done the job correct.

Flintshire would not let my son test he only had a C&G2391 (Level 3 inspection and testing) only I was allowed to test because I had a level 5 degree in Electrical and Electronic engineering. He also wanted to see the test equipment we would be using.

The rules have changed to start with the cost of inspection and testing to show your results were OK was born by the council. Today they can charge extra so if it fails they can charge each time they come to re-test.

Some councils will accept an Electrical Installation Condition Report in place of the installation certificate others will not. Clearly if you get an Electrical Installation Condition Report done you could copy the results onto an electrical installation certificate and sign it. But really what should be done is use a three signature certificate so design, installation and inspection plus testing can all be done by different people.

Some scheme operators will now allow there members to test but many required the electrician to use a single signature form only. So the form would need submitting to LABC not the scheme operator and you would have to pay both the electrician and LABC.

In the main the LABC charges have resulted in it just not being cost effective to DIY. Wales has a standard charge it was £100 plus vat for the first £2000 worth of work. Add to that the electricians charge and your talking about more to get it signed off than to get a scheme member electrician to do the whole job.

Because the work I was doing was for the disabled it was FOC so yes worth doing but in the main just not worth the effort.

Do remember it does vary county to county so always worth asking at county offices but I would be surprised if worth doing DIY.

In the main DIY = Illegal and dangerous. OK there are some who jump through the hoops and hire test equipment but very few and far between.

 

[STEVEROG]

Regarding notification of work, building control were made aware many moons ago that I would be carrying out all electrical work associated with the loft conversion and other renovation work to my property. They've been paid. Am I missing something here? is there some other demi-god I need to inform? Some other body of persons who want a pound of flesh?

All things considered, I think I'll get a sparky to come have a look and quote.

BTW, I'm pretty sure I already have an isolator switch fitted...happy days!

 

[STEVEROG]

Oh one final thing...

I say mention in one the replies about DIY being illegal and dangerous....

I suggest people have a look at the IET web site (they're the governing body who just happen to have written the rules....formerly the IEE). I don't recall the exact wording now but its something like "Although DIY work is discouraged it is permitted......." the whole part P is very misunderstood! IMHO it's a real carve up and will probably result in discouraging fixed wiring due to the fear of prosecution with extension lead lash ups used instead based around lots of multi-plugs and extension leads......unless there's now a law regarding the sale and use of these!

 

[ericmark]

Regarding notification of work, building control were made aware many moons ago that I would be carrying out all electrical work associated with the loft conversion and other renovation work to my property. They've been paid. Am I missing something here? is there some other demi-god I need to inform? Some other body of persons who want a pound of flesh?

All things considered, I think I'll get a sparky to come have a look and quote.

BTW, I'm pretty sure I already have an isolator switch fitted...happy days!

Then ask your LABC it's no good asking here. As I said Liverpool were very helpful and it was easy. The LABC inspector is like god what he says goes.

Simple idea is if your wiring then your testing if you can't test then don't wire. Yes we still have the apprentice system and an electrician can allow an apprentice to do work and then he signs it off. But it's all from the start of the job. So electrician designed and says do that then checks it done correct. He does not let the apprentice lose to do what he likes he is supervised.

So same applies with you. Be it the building inspector or electrician they say do that then you do it and they check done correct and sign.

The building inspector however does NOT issue an installation certificate he issues a completion certificate and there is nothing to say you MUST have an installation certificate.

 

[JohnW2]

Oh one final thing... I say mention in one the replies about DIY being illegal and dangerous....

Yes, I very nearly responded to that myself.

As for 'dangerous' (which, after all, is what really matters), I'm sure that a (perhaps very) small proportion of DIY electrical work qualifies as 'dangerous', but the majority is probably 'OK', and a significant proportion is very good.

'Illegal' is more difficult. What eric probably had in mind was that it can be argued that for any electrical work to be fully 'legal', it should be subjected to 'proper tests' to prove that it is satisfactory and safe - and only a tiny minority of DIYers have (or acquire) the equipment and/or knowledge required to undertake those tests - so the 'proper tests' do not get done. In that sense, it could be argued that most DIY electrical work is technically 'illegal'. However, that by no means indicates that it is dangerous or unsafe (in the great majority of cases it won't be), merely that tests to prove that it is safe have not been undertaken.

Kind Regards, John

 

[ericmark]

I would agree in the majority of cases DIY would will not be dangerous.

However even professional work can be dangerous if it's not tested not because what the electrician has done but what other trades have done.

It has just been reported on how a foreman has be found guilty over the death of a lady when he failed to ensure tests were done correctly. It was not the workmanship but the tests which caused the problem.

This is the report on what I am talking about there is more here as I have said it was not the workmanship but the testing and as a result missing the fact that the plasterer had damaged the cable.

There has been many discussions as to Part P and the LABC as to who is responsible. It says the local authority is responsible for site safety once you register the work. But watch any builders from hell TV series and they seem to side step the blame every time. One wonders why one pays a LABC when they don't seem to take responsibility for what is done.

In the main authorities tend not to take DIY people to court for mistakes I think the thought is they have already suffered enough. It normally is considered an accident. When a professional does it however there is no such thing as an accident some one is to blame.

But I am sure if you did a risk assessment using how many DIY jobs go wrong then the risk is quite low. I would have also said the risk of my son getting an electric shock in my house when he was 5 was also low but never the less I fitted RCD protection to all circuits 25 years ago just in case. As he grew up he became a radio ham then electrician and now an electrical engineer and at the age of around 14 when he took and passed his RAE he did trip the RCD quite a few times during his experiments. He's 30 now so looking back 25 years when I fitted the RCD's yes likely that action saved his life but I will never know that for sure.