Rcbo ?? Outside of CU.

[joesoap13]

Hi Guys, in need of some advice please.
Bare with me, I am no electrician.
Been in house 26 years, it was rewired before I moved in.
I bought it of an electrician.
Beginning of this year, had new kitchen installed, the electrician was needed to instal 6 ceiling lights, and new appliances.
The CU had not any rcd’s, only fuses, so he advised I replace with rcd’s .
There was/is no rcb for whole house, is it rcd or rcbo ?
I said it would be just as cheap replacing the CU, which has it in ?
He said, to do that, he would have to spend a lot of time checking all switches, plugs etc, to issue a certificate, and didn’t seem keen !
He recommended putting a rcbo between the meter and CU, which he had, and could issue a cert, for his work,so I agreed, wanted the cert.
Cut a long story short, when he had done all the wiring, he tried installing rcbo,”But, he said the ring main and light circuit were tripping, but, the new rcd’s in CU were not.
Some thing earthing probably.?
Never unplugged any devices, to see if it was any of them, just took rcbo out again.
He didn’t show me it tripping !
Out come, no cert.

I asked if he wanted to find the faults,to issue the cert, and give me peace of Mind I was up to date, I know a cert is required if I should sell the house ?
He didn’t really want to, busy, he does offices, and only houses, occasionally, as a favour to kitchen fitter.
He said it could take days, and still not find the faults.
I have mice all the time, could have chewed cable, anything could be at fault ?

Covid hit!kitchen finished just in time.
So, no workmen.
Payed I’m off.
Wife shielded, still is.
I would like the faults found and a cert, at some stage.
How difficult is it to find the said faults.

I would like some advice, whether to ask him back to do work or get someone else ?
I am happy with his work.
Is an rcbo outside of CU ok to issue a cert.?
One relies on what the professsionals tell them, I went with his.
Sorry it’s so long.
All electrics are ok, and always were.
Just not up to date.
Appreciate any advice in advance.

 

[EFLImpudence]

Your terms are not clear enough.

Post a picture of the CU and anything else that has been fitted.

Just copy and paste or drag pictures.

 

[joesoap13]

Thanks for reply, much appreciated.

 

[JohnD]

It can be quite difficult to track down earth leakage faults, which means that the time, and therefore the cost, cannot be determined in advance. Rodent damage to cables is a common cause.

The consumer unit you show is rather an old type and not suitable for RCBOs.

Putting a single RCD in the supply to the CU is a very bad idea because as you have found, it is quite likely to trip, and will turn off everything in the house.

It would have been possible to add a new CU and connect just your new lighting circuit to it, and issue a certificate just for that lighting circuit. That might be your simplest and cheapest option. Sometimes people do that, adding quite a large one so that the remaining circuits can be transferred into it when time and funds permit.

But I have a feeling that the electrician you used is either inexperienced, or unwilling to solve your problem, so maybe ask around for personal recommendations from people you know and trust.

Online paid-for advertising companies, masquerading as recommendation sites, are not a good source.

(an RCBO protects a single circuit, and provides both overload/short-circuit protrectn, and earth leakage protection. RCD is a broad term, but in your case would mean a single device that provides earth leakage protection only, to one or more circuits which have their own overload/short circuit protection in the form of individual fuses or miniature circuit breakers).

 

[sparkwright]

In your existing consumer unit, the individual breakers on each circuit are MCBs. These are used instead of fuses. They offer no RCD protection.

Sometimes an MCB can be replaced with an RCBO, which offers overcurrent AND RCD protection.

Unfortunately RCBOs will not fit your CU.

The RCD that apparently was to be fitted between your meter and CU is called an RCD or more specifically an RCCB.

The trouble with this arrangement is that one faulty circuit would cause total power loss, which is inconvenient.

If a faulty socket circuit causes an RCD to trip, the obvious thing to do is to unplug every appliance, and then see if the RCD re-sets.

 

[EFLImpudence]

The CU had not any rcd’s, only fuses, so he advised I replace with rcd’s .

What you have is MCBs (Miniature Circuit Breakers) which plug in to the old fuse holders.

There was/is no rcb for whole house, is it rcd or rcbo ?

It would be an RCCB (Residual Current Circuit Breaker)
There should not really be one for the whole house as tiny fault would switch off everything.

I said it would be just as cheap replacing the CU, which has it in ?

Yes it would be the best way.

He said, to do that, he would have to spend a lot of time checking all switches, plugs etc, to issue a certificate, and didn’t seem keen !

It would involve testing all circuits.

He recommended putting a rcbo between the meter and CU, which he had, and could issue a cert, for his work,so I agreed, wanted the cert.

That would be an RCCB as above.

Cut a long story short, when he had done all the wiring, he tried installing rcbo,”But, he said the ring main and light circuit were tripping, but, the new rcd’s in CU were not.
Some thing earthing probably.?

That's right. Could be difficult to find. MCBs in CU

Never unplugged any devices, to see if it was any of them, just took rcbo out again.
He didn’t show me it tripping !
Out come, no cert.

Ok.

I asked if he wanted to find the faults,to issue the cert, and give me peace of Mind I was up to date, I know a cert is required if I should sell the house ?

Well, theoretically - but if you say you haven't got one that's fine.

He didn’t really want to, busy, he does offices, and only houses, occasionally, as a favour to kitchen fitter.
He said it could take days, and still not find the faults.
I have mice all the time, could have chewed cable, anything could be at fault ?

True, on the other hand ???

Covid hit!kitchen finished just in time.
So, no workmen.
Payed I’m off.
Wife shielded, still is.
I would like the faults found and a cert, at some stage.
How difficult is it to find the said faults.

It could be very time consuming. Could be easy.

I would like some advice, whether to ask him back to do work or get someone else ?
I am happy with his work.

He doesn't seem to like domestic work so you may have to find someone else.

Is an rcbo outside of CU ok to issue a cert.?

The certificate is not the important bit - and as above, one RCCB not the best solution.

One relies on what the professsionals tell them, I went with his.
Sorry it’s so long.
All electrics are ok, and always were.
Just not up to date.

That does not mean it must be replaced.

Just get someone to find the faults first.

 

[EFLImpudence]

MCB - Miniature Circuit Breaker - Overload, Short-Circuit and Earth-Fault protection.
RCCB - Residual Current Circuit Breaker - Earth Leakage detection.

RCBO - Residual Current Device with Overload protection - both types of protection.

RCCB and RCBO are both RCDs - Residual Current Devices

 

[joesoap13]

Thanks for both your replies, very helpful indeed.


As I have no money problems, the cost is not an issue, as long as it’s right and safe, and necessary !
That’s why I suggested a new CU, in the first place,it cost £80 to replace fuses with mcb’s
If I opted for a new CU , is circuit rccb protected, so if lights fail, the ring main is still ok ?
I caught three blind mice last week, have umpteen all year round .
Learn to live with them,near stables , fields.

How does one test circuit, if fault is not visually found ?
Hidden cables etc ?
As my electrics have been without rccb’s for this long, with no problem, is it a personal safety issue or can I carry on as it stands relying on mcb’s ?


I would imagine most households only upgrade electrics to regs, when work is carried out, or house is being sold and cert required.

What is the ball park figure to replace my CU ?
finding the faults, plural, as both circuits are faulty according to him, would then have to be done , and paid for depending on time.
It could even be a fault in what he has done ??

Is this what you are both advising
What CU do I require ?

He and all the tradesmen were on day rate, cash, no quibbles, that’s why I wasn’t happy about it not being done.

 

[JohnD]

If I opted for a new CU , is circuit rccb protected, so if lights fail, the ring main is still ok ?

The finest way to do that (the most expensive) is to have one RCBO per circuit.

A fault on any one circuit will not cause any other to fail (sometimes there can be a momentary surge or pulse which may trip others if nearby, but they will reset)

If you are getting a new CU, have any other electrical work (additional sockets, outdoor lighting, shed supply etc) done at the same time.

RCD protection is valuable in reducing deaths from accidents, such as kneeling in a puddle of water and touching a pipe that is live; touching a knife-rack in a kitchen where the fixing screw has penetrated a cable in the wall; playing with the cut flex on an old plug that a person has left where a child found it; dropping an extension cable charging a tablet while having a bath; dropping a worklight into a water tank and instinctively grabbing it. These are all real-life examples of fatal accidents. Thankfully they are rare.

 

[EFLImpudence]

If I opted for a new CU , is circuit rccb protected, so if lights fail, the ring main is still ok ?

Not really you could have Main Switch and two RCCBs each protecting half the circuits.
Best as money no object would be a Main Switch and an RCBO for every circuit.

I caught three blind mice last week, have umpteen all year round .
Learn to live with them,near stables , fields.

They do chew cables.

How does one test circuit, if fault is not visually found ?
Hidden cables etc ?

You need special instruments that test the cable insulation.
A quick test can be done with an Earth Leakage Clamp Meter which will test each, or all, circuits to see if there is any, and how much, earth leakage (if any currant has "escaped" ).

As my electrics have been without rccb’s for this long, with no problem, is it a personal safety issue or can I carry on as it stands relying on mcb’s ?

Well - only if something goes wrong - like seat belts.

I would imagine most households only upgrade electrics to regs, when work is carried out, or house is being sold and cert required.

Yes, all new work must be to latest regulations.

What is the ball park figure to replace my CU ?
finding the faults, plural, as both circuits are faulty according to him, would then have to be done , and paid for depending on time.
Is this what you are both advising

Difficult to say how much.
As I said, find the faults first.

What CU do I require ?

If you mean make, I, and I think we, like Hager.
Go to this site and look at 'switchgear' https://www.discount-electrical.co.uk/section.php/100017/1/switchgear

 

[JohnD]

incidentally, I favour getting one that is bigger than you need (a large, empty tin box costs little more than a small one) because it makes it so much easier to add an extra circuit in future; maybe a garden socket, or an electric car charger, or a new shower, or outdoor lighting, or a shed supply, or a burglar or fire alarm, or a bigger cooker, or all of them.

(BTW I put some more examples of accidents in my earlier post)

 

[joesoap13]

Thanks guys, much appreciated, looks like getting someone to find the faults first, if indeed there are any.
I only have his word for it !
Finding and fixing it, could only be temporary as mice are here all year round, if they are at fault.
Then A new CU as you both suggested.
As wife is still shielded and due to be in covid 3 soon, a bit of homework necessary.

You have both been very helpful, thanks again.

 

[AndyPRK]

get a different domestic elec. in to fit you an all RCBO board (£700 ish) or do an EICR in advance (£125) to look for faults
They are very busy ATM

 

[ericmark]

You can fit RCD protection as I have done here. But that was done around 1992 when consumer units with it all built in were not around. And it has cost me around three freezers full of food when it has tripped while away.

My son has every intention of replacing it with a modern unit. This house I decided the extra £100 to have all RCBO's was worth it, specially as I need to go outside to reset anything. Tripping is such a random thing, as said I have had RCD protection for nearly 30 years, and I could go 18 months or 2 years without a trip, then trip twice a week for a month and then another 2 years without a trip and never did find anything wrong.

Here I have had it trip once, good reason, roof leaked and water got in a socket, but that was one circuit of 14, and I could manage without it. So RCBO may put a £150 pound extra on price but well worth it.

 

[joesoap13]

Thanks very much.
Can I ask for the kite mark, or registered body said person should be qualified to.
The last one went on about, “ it had to be right, his job depended on it”
He kept pointing to his pocket with his letters of his body he was qualified to.
To his defence, he said he specialised in office work, not houses, but, testing a circuit in any system would be the same surely.
Why did he not test the circuit first, instead of fitting the rccb, and removing it because it tripped both circuits ?
I may as well have left fuses in, until he had finished his wiring, he had me chasing round for green rcd holders, only to be told they are no longer in use, for the Hob!
It was £80 plus wasted for mcb’s which will be useless when board is changed.

He should have known this .!
Cheers