Pyro Help Please

[Welshsparky]

Hi all

Changed a consumer unit today, Advised customer on PIR first but to no avail, so i changed the old consumer unit for a 17th edition dual rcd one, All circuits fine apart from the lighting circuit which trips instantly, Did the standard tests and found allsorts of problems with the neutrals and earths throughout the circuit , Now the problem i have is the entire installation is Pyro , Theirs no loft or floorboards ( second floor flat) so i have no minimal access to cabling, Advised the customer the lighting circuit needs rewiring, But they dont want to go for it and keep explaining to me " It worked before" ( May i also add the customer is polish!!) Now as a temporary measure until i get back their next week ive put the lighting circuit on the mainswitch side of the consumer unit , to atleast give the tenant lighting, Can anybody advise me on the best way to go about this as this work has to be certificated and i dont want to put my name anywere near this lighting circuit !

Many thanks

 

[rich.250]

No its not I hope you fitted a FCU with a 5 amp fuse please say you did if not then you have a 60-100 amp fuse protecting the circuit

I interpreted this as on a cb on main switch. Could be wrong. If no cb I take back what I said lol

 

[oldtimer]

I interpreted this as on a cb on main switch. Could be wrong. If no cb I take back what I said lol

Well if he has configured it this way the circuit is now being protected via a CB instead of a 3036

 

[RISElectrical]

Silly question but are you sure you haven't damaged the pot when changing cu?

 

[Guitarist]

If nothing else, always check LN-E IR before accepting a CU change. No good to u now, but any lesson learned is a good one

 

[Engineer54]

As i see it, you need to progress a testing exercise through the circuit, marking and inspecting each core as you go. As others have stated this sounds more like something has been disturbed, a pinched cable, or a previously damaged sleeve that's now allowing the conductor to come into contact with something. It's a bummer i know, but it needs to be fixed at the end of the day.... lol!!

 

[Des 56]

All sorts of problems throughout with neitrals and earths will in all probability be one or perhaps two sections.it can and should be traced with little effort and they can decide on remedial action if agreed

As far as doing tests prior to a consumer unit change,its each to his own,I personally do nothing other than a cursory glance at the installation,but with the attitude that if something is amiss,I will sort it

If there has been no disturbance to the pyro pots.it probable its not cable faults,rather poor connecting or faulty fittins
It seems to be you took the job on and should try and pin down where the faults are arising,rectifying those faults is a different matter
With the required work needed to put it right explained to the customer.its their decision.if they dont agree to problem sorting, then you have done all that could be reasonably expected
Leave it with overcurrent protection and note the problem on the Eic and get paid

 

[Welshsparky]

Lights were left on a 6 amp cb , thanks for all the information guys , much appreciated , will be back on the job Wednesday , shall let you know how it go's.

 

[oldtimer]

Welshsparky i was not giving you a hard time but I have come across this once to often 90% of the time for burglar alarms and the rest for door entry systems and I have seen one on a RCD board where the guy did it as a stop gap and never went back and that was 4 years ago

 

[Adam W]

Surely this is precisely the reason an EICR needs to be done beforehand? If it were optional very few customers would go for it (or at least pay for it), after all there doesn't seem much point testing an old CU which is going to be changed straight after anyway.

 

[spark 68]

after all there doesn't seem much point testing an old CU which is going to be changed straight after anyway.

True, but this should not stop some basic checks such as IR L+N-E, Ze, and checking for borrowed neutrals etc., how in depth you check depends on the condition and age of the installation, how much DIY bodgery has been done and so on before carrying out a CU change, this is in my own interests.

I rarely carry out a full blown EICR or full I&T because as you say, most clients would not pay for it, but I always test as much (or as little) as I think I need beforehand at the survey stage, as mostly these installations did not have RCD protection before the CU change, and I don't like nasty suprises, Besides some of the test results may not change and can go on the EIC.

I also explain, before the change, that any faults found will need to be rectified at further costs to the client.

 

[Strima]

I've the learnt the hard way, as many others probably have. Test before installing, even basic tests will give you and idea if the new CU will function properly without any remedial work. You can then advise the customer that there are problems that need sorting and not try to argue the point after the new CU is fitted.

In the grand scheme of things a few basic tests can save hours of headaches and arguments.

 

[Risteard]

you are saying trhat you are leaving the lighting curcuit non-rcd protected. it's no less safe than before, but cover your arse and make sure it's noted on the EIC as a fault that the customer refuses to pay for rectification.

There is no requirement to RCD protect a lighting circuit wired in MIMS cable.

 

[Adam W]

There is no requirement to RCD protect a lighting circuit wired in MIMS cable.

We had this discussion when I did the 2382 - MI may have an earthed sheath but it still isn't capable of withstanding penetration by a screw or nail or suchlike.

 

[Adam W]

True, but this should not stop some basic checks such as IR L+N-E, Ze, and checking for borrowed neutrals etc., how in depth you check depends on the condition and age of the installation, how much DIY bodgery has been done and so on before carrying out a CU change, this is in my own interests.

I rarely carry out a full blown EICR or full I&T because as you say, most clients would not pay for it, but I always test as much (or as little) as I think I need beforehand at the survey stage, as mostly these installations did not have RCD protection before the CU change, and I don't like nasty suprises, Besides some of the test results may not change and can go on the EIC.

I also explain, before the change, that any faults found will need to be rectified at further costs to the client.

I meant from the customer's point of view. You should carry out the relevant inspections and tests before changing the CU to identify these problems and deal with and charge accordingly.

 

[malcolmsanford]

We had this discussion when I did the 2382 - MI may have an earthed sheath but it still isn't capable of withstanding penetration by a screw or nail or suchlike.

It doesn't have to withstand penetration from a screw/nail, the same as T + E can not withstand penetration.

MICC cable is BS 60702-1 and therefore comes under regulation 522.6.100 with regard to being buried less than 50mm, and so does not need RCD protection.

But regardless of that, if there is a fault then it should be found. If it is a case of borrowed neutrals etc then stick it on an MCB.