cu change

[martinsayer81]

quick question

if i was changing an old fuse board to a new c/u, and i was installing 3 new circuits,
would i have to fully test all the old wiring before connecting it all up?

and what if the old wiring keeps tripping the new rcd?

how would you guys go about it??

 

[Richard Burns]

but i wouldnt be responsible for livening up an existing circuit that has a 230V fan in zone 1 of a bathroom, would i?

in that situation would i advise the customer of the dangers and make a note on the certificate

A 230V fan is allowed in zone 1 of a bathroom (if it is IPX4).

You do not have to have the circuits installed to BS7671 but they must be safe to use, you cannot fully assess a circuit for complete compliance but you should ensure that it will meet ADS requirements and does not present an immediate danger, you should mention when doing the initial survey, that the following.... will need to be corrected before changing the CU at x cost.

Geoffsd you need to explain to the customer that it is necessary to ensure that the system is safe for the CU change and rectification of faults may cost more. I did a very thorough EICR for one property before changing a CU and never heard back from him after that, but at least I was not asked to leave a dangerous situation.

 

[Strima]

Inspecting before hand will also tell you what size/type of CU you will need. No telling how many circuits have been jammed into the old one over the years, not unknown for garage supply to be jumped of the back of the cooker fuse etc.

You can then design the board to suit your needs and a bit of future proofing, all well and good shooting down to the bog orange shed for a BG £50 special but you may end up with lots of unused MCB's and not enough of the ones you need. Nothing wrong with BG boards but they don't give you many options on the populated ones.

 

[telectrix]

most populated boards come with "standard" MCBs. as you would want in a usual installation. my last BG board install needed a couple of 20A for 2 radials, but 1 of my suppliers stocks'em, so no sweat.

 

[Mark_Burgess]

quick question

if i was changing an old fuse board to a new c/u, and i was installing 3 new circuits,
would i have to fully test all the old wiring before connecting it all up?

and what if the old wiring keeps tripping the new rcd?

how would you guys go about it??

I think you should have a good read of this thread.
http://www.electriciansforums.net/e...ctrical-regulations/12971-cu-changes-you.html

If you take the time to browse the forum "stickies" (The top section of posts at each part of the forum) you will be surprised at what you can learn.

 

[telectrix]

surprised nobody's yet mentioned earthing and bonding requirements, or did i miss it , going for a refill?

 

[Octopus]

surprised nobody's yet mentioned earthing and bonding requirements, or did i miss it , going for a refill?

I was going to but was waiting for someone else to stick their oar in!

 

[oldtimer]

Not quite with you on this.
If you do tests and find all's well, what do you tell the customer?



Generally,though, I've always been a bit mystified about the recommendations to do a full EICR first.
If you find several or lots of faults and tell customer it'll cost so much if they want new CU how do you get them to pay at least £150 for the EICR if they decide not to pay for repairs and new CU after all?

Well with a TNCS supply you have to upgrade the earthing and with a global IR I get the circuit with the lowest reading all good stuff for me but I am not exactly going to tell the customer my findings and yes there should be a full EICR befor any work commences but thats just not the way it goes I also check the state of the DBs cables and do a couple of Zs tests at some sockets

 

[Guest111]

Also if changing a board it,s worth explaining what an rcd does,as it may save you getting a call back saying "the electric goes off when I plug in my iron etc and it never did with my old one(wylex) had that once or twice.

 

[Strima]

surprised nobody's yet mentioned earthing and bonding requirements, or did i miss it , going for a refill?

I did think about it but then that would be obvious wouldn't it??? :lol:

 

[needasparks]

I did think about it but then that would be obvious wouldn't it??? :lol:

You would think so but then so many questions on here are. assume and all that.......

 

[Steve_P]

I did think about it but then that would be obvious wouldn't it??? :lol:

The only obvious reply is the one the OP says DUH! to, other than that, nothing is obvious. Same as there's no stupid question, only a stupid answer?

 

[DNG]

Quick answer is yes all circuits should be tested. With this job two certificates would be produced (if required) "arguments will ensue" one an electrical installation cert ( through the EICR docs.) for the three new ciruits, and a periodic electrical cert (again through the EICR docs.) for the changing of the CU. It must be stressed that the changing of a consumer unit is a change in an existing installation and should never be covered under an electrical installation cert. which is for NEW installations only. Then with regards to possible old wiring tripping, then fault finding will have to be carried out. viz. unplug all appliances and megger between live and neutral to earth of all circuits. Ensure that the main neutral is disconnected from system, either by the double pole main isolator, or by disconnecting from main neutral connection.

 

[RISElectrical]

Somebody mentioned quoting 2 days for a CU change? That's gonna be expensive!

Just do some test beforehand as mentioned. Personally there aren't many customers IMO that would pay for an EICR as part of the job. As for walking away from a job if they won't pay for one, sod that. Just make sure on the test sheets for the cu it clearly states cu change only. Ensure bonding is all good and that zs complies. You'd have already done the IR bits and would more than likely have the r1 r2 also. So test sheet done.

New circuits need a seperate EIC

 

[telectrix]

changing of a consumer unit is a change in an existing installation and should never be covered under an electrical installation cert. which is for NEW installations only​

sorry mate, thats rubbish. an EIC is necessaryt for a CU change. what else would you use?

​

 

[Octopus]

It must be stressed that the changing of a consumer unit is a change in an existing installation and should never be covered under an electrical installation cert. which is for NEW installations only.

So please enlighten me as to how you would certificate a CU change??