New Home Electrics - Faulty Wiring ?

[steevo_Tabasco]

[SIZE=medium]Hi all, [/SIZE]

[SIZE=medium]1st[/SIZE] post please be gentle …

[SIZE=medium]Recently have moved into a new house (property is recent build 2yrs old)[/SIZE]

[SIZE=medium]After the move we noticed the electrics kept tripping (even just switching a light on would overload the system)[/SIZE]

[SIZE=medium]After a bit investigating we found out the electricity supply enters our house from the street into our garage > then into a breaker box > one of these breakers feeds into the utility room where it terminates into a another breaker box with all house ‘electrics’ controlled from here [/SIZE]

[SIZE=medium]We contacted our electrician to come have a look as im alittle worried something may not have been done correctly – see main extract as below : -  [/SIZE]

[SIZE=medium]The main incoming 25mm cable supplies a 5 way garage consumer unit, the load supply from the main switch in this consumer unit which feeds the MCB’s and RCBO’s is linked with 6mm single cable and not a busbar as you would expect,  the 6mm cable is undersized for this installation. The house consumer unit is then supplied from the garage consumer unit with a 63amp MCB and cabled with 16mm twin and earth, again this is undersized for this installation due to the loads present from the property. The 63amp MCB is currently tripping under load conditions.[/SIZE]

[SIZE=medium]To summarise; the main incoming cable should supply the house consumer unit and the garage consumer unit should be fed from an RCBO within this consumer unit. The garage consumer unit should be repaired or replaced to allow a busbar to feed its devices.[/SIZE]

[SIZE=medium]after contacting previous owner he returned with his own electrician to diagnose rectify the problem - he diagnosed the tripping problem to be a faulty mini-breaker / RCD out in the garage (after replacing we have had no further incidents, but I am worried from the sparky’s report that we may have a poorly ‘wired’ up house or potentially a fire hazard if wires are undersized ?!?)[/SIZE]

[SIZE=medium]Can anyone advise whether my home electrics have been done on the cheap or is second sparky inventing work ? - what should be my next steps ?   [/SIZE]

[SIZE=medium]Thanks, [/SIZE]

[SIZE=10pt]Steven[/SIZE]

 

 

[ProDave]

It's important to determine if it's an MCB or an RCD that's tripping (an RCD will have a little "test" button on it as well as the on off "switch")

If it's a 63A MCB that is tripping, then you must be running some VERY large loads in the house, i.e electric shower, oven, microwave, toaster and kettle all at the same time. Very unlikely.

If it's an RCD that's tripping it most probably points to some appliance in the house that has a fault.

More information please.

A 16mm cable can carry up to 76A (depending how it's installed) so that is probably okay. And in any case, an under sized cable would just get a bit warm and would not trip (unless it's got warm to the point of melting) but that would only happen if you have all the aforementioned heavy loads running at one time.

The missing busbar in the garage CU really wants replacing, but again, having a single core cable instead will just get a bit warm under haeavy load, and will not be the reason for your tripping.

EDIT:

Just re read it, and he says the "63A MCB is tripping under load conditions"

Did he do any other testing? If not, try a better sparky.  I would expect him to do some current measurements to determine exactly what load is being drawn when it trips.  It's also possible you have a short circuit somewhere, again I would have expected him to do some more testing to try and find that.

 

[SLIPSHOD & SLAPDASH]

Agree with Dave here. Do you have electric heating. It would be very unusual  for a house to  trip a 63A breaker due to overload as the breaker would probably hold nearer 85A before it would trip.

 

[wozz]

There are a few badly worded things in your electricians statement. Also he is suggesting the supply gets moved to the utility room, I do not know the layout of your house but I would have thought this is very unlikely to happen. 

 

[Blue Duck]

Also agree with the above, sounds like your spark was fishing for more work.

Did you get an electrical installation certificate either from the previous owner or as a part of the mortgage agreement? If not It way be worth getting an inspection done for piece of mind?

Get Dave round

 

[kme]

Concur with my colleagues.

Although I`d be unhappy with the 6mm interlinks; and the house being subbed from the utility (though there ARE acceptable reasons for doing that) - it`d be interesting to know how much load you`ve got in the house - enough to trip a 63A MCB is a HUGE amount of power to use!!!!

However - if the original sparks fitted 6mm wire in the utility DB - I don`t trust HIS work as far as I could throw him.

The second sparky, who`s comments I assume you`ve posted verbatim, doesn`t seem to have done much testing - in his position, I`d have been VERY interested in HOW you were overloading a 63A breaker, to be honest.

My recommendation would be to get a time-served, competent electrician, to perform an "electrical installation condition report" - NOT a " visual condition report". The results of the testing & inspection involved should highlight any issues with the installation, and the best way to proceed with "making safe".

Where are you? Perhaps one of our members is somewhere near?

 

[steevo_Tabasco]

Thanks for the comments ...

previous owner sent out his electrician who replaced a faulty circuit breaker (the 63A breaker in garage) this breaker feeds the whole house thru the 2nd breaker box in the utility room - this was done last week - had no issues since then (I had to set the reset 'lever' on this breaker to about 2/3's on to get it to stay on - setting lever to the fully on position tripped the power - which got me thinking it was a diodgy breaker in 1st place ?!?)

as to whats running in the house - heating is gas & I aint running anything mega in the house (no welding generators or flux capacitors )

1st was during the nite on our 1st nite woke up to no power (thoguht we had been cutoff?!?)

2nd trip was learly evening > TV > dishwasher may may not have been on  > think the trip happened when 1x of my kids switched toilet light + extractor on   

3rd trip was switching on electric shower upstairs

4th trip was late @ nite so lights were going off sky box + tv off ...  

in our sparkys defence he did the inspection / observation job as a freebie so we could go back to our solicitor (as we were worried we are runnign out of 'snagging period')

thanks for the advise guys - will try to obtain the Electrical Installation Cert. of previous owner & get a EICR done by ourselves

will post a conclusion part when i get it all fixed ?

Cheers,

SteevO

P.S. property is in Glenrothes (Fife)

 

[ProDave]

It sounds like the major issue, replacing that faulty 63A breaker, has been done.

the only thing I would probably worry about now is getting that busbar replaced.

To be honest, if you want the job done, pay an electrician to come and do it. Anyone doing a freebie for a mate, will do the very minimum he has to to "fix" it.

 

[Evans Electric]

It sounds to me as if its wired up "arse about face"    .  The mains into a garage unit and the house board wired as a secondary item .  It should be the other way round  , the incoming mains feeds the house consumer unit and the garage is just a sub-main or final circuit from there.    

I was about to say if its only two years old it should have been wired by a "competent person " and the installation notified to Local Building Control but then saw that you are in non Part Peeland.  

 

[ProDave]

It sounds to me as if its wired up "arse about face"    .  The mains into a garage unit and the house board wired as a secondary item .  It should be the other way round  , the incoming mains feeds the house consumer unit and the garage is just a sub-main or final circuit from there.    

I was about to say if its only two years old it should have been wired by a "competent person " and the installation notified to Local Building Control but then saw that you are in non Part Peeland.  

In Non Peeland, Building control demand to see an EIC from the electrician before they will sign it off as complete. So that's going to be no better or worse than any EIC issued in the UK.

In fact 10 years ago, before anyone was peed, ALL that BC up here wanted was ANYONE to sign a single sheet of paper saying "the electrics are okay" So now the fact they require a copy of a proper EIC is a tightening of standards.

I agree the arrangement of consumer units sounds unusual, but nothing actually "wrong" with it.

 

[batty]

A couple of roads from where I live they have a similar set up. These houses are probably worth at least 400k. They have a 60 amp switch fuse in garage, from this a piece of 16mm TW/E goes underground to fuse box in house. I know for a fact the cable doesn't even go through a duct absolutely disgraceful. Whoever designs these jobs wants shooting.

 

[SLIPSHOD & SLAPDASH]

A couple of roads from where I live they have a similar set up. These houses are probably worth at least 400k. They have a 60 amp switch fuse in garage, from this a piece of 16mm TW/E goes underground to fuse box in house. I know for a fact the cable doesn't even go through a duct absolutely disgraceful. Whoever designs these jobs wants shooting.

I also know a whole estate in Stevenage where the supply is into the detached garage and then a buried 16mm tw&e feeds  a 2nd  board in the kitchen

 

[Sidewinder]

Thing is by the time anyone figures out that it is wrong, any "warranty" has expired.

The case should be that if it is wrongly designed & installed at the outset there should be no statute of limitations or warranty that will protect you.

Do it wrong and it will come back to bite you and will be rectified at your cost, that is not far off the consumer rights regulations that exist now TBH.

 

[batty]

Trouble is the original builder went bankrupt so not sure if the finishing builder could be sued for poor work he may not have done that stage of the build. 

 

[pewter]

In Non Peeland, Building control demand to see an EIC from the electrician before they will sign it off as complete. So that's going to be no better or worse than any EIC issued in the UK.

In fact 10 years ago, before anyone was peed, ALL that BC up here wanted was ANYONE to sign a single sheet of paper saying "the electrics are okay" So now the fact they require a copy of a proper EIC is a tightening of standards.

I agree the arrangement of consumer units sounds unusual, but nothing actually "wrong" with it.

sounds strict up there, having to show an EIC, and even sign something.

Down here in relaxed P world i just need to log on tinternet, put in an address and cert number and it all done. The cert might not even exist.

 

[binky]

[SIZE=medium]The main incoming 25mm cable supplies a 5 way garage consumer unit, the load supply from the main switch in this consumer unit which feeds the MCB’s and RCBO’s is linked with 6mm single cable and not a busbar as you would expect,  the 6mm cable is undersized for this installation. The house consumer unit is then supplied from the garage consumer unit with a 63amp MCB and cabled with 16mm twin and earth, again this is undersized for this installation due to the loads present from the property. The 63amp MCB is currently tripping under load conditions.[/SIZE]

[SIZE=medium]To summarise; the main incoming cable should supply the house consumer unit and the garage consumer unit should be fed from an RCBO within this consumer unit. The garage consumer unit should be repaired or replaced to allow a busbar to feed its devices.[/SIZE]

16mm FTE is correctly sized for 63Amp MCB.

you don't need to change fuse board to insert a bit of busbar - I have lots of offcuts in my tool bag from various board changes, and probably wouldn't even bother to charge you for inserting a small length into the board. You can even buy 1m lengths of busbar from wholesalers for about £10.

I would trust your sparky as far as I can wee, either the guy isn't fully competent with the regs or he's trying to put the frighteners on you. Either way avoid!!!

 

[SLIPSHOD & SLAPDASH]

16mm FTE is correctly sized for 63Amp MCB.

I would trust your sparky as far as I can wee, either the guy isn't fully competent with the regs or he's trying to put the frighteners on you. Either way avoid!!!

You cant comment like that without knowing length of run & installation methods .

 

[jackl86]

You cant comment like that without knowing length of run & installation methods

If its a housing project and their own garage it's not going to be 100 metres away is it 

 

[SLIPSHOD & SLAPDASH]

If its a housing project and their own garage it's not going to be 100 metres away is it 

100M !  , last one i worked on similar to this had about  20M run of tw&e buried in an insulated floor. Work out that.

 

[jackl86]

100M !  , last one i worked on similar to this had about  20M run of tw&e buried in an insulated floor. Work out that.

Point being its going to be a relatively short run so unless its something nobody has ever seen before 16mm would be ok