Switch from RCD to RCBO consumer unit?

[niceandripe]

Hello, i wonder if anyone can help, firstly i just like to say i have recently started a 2330 course but its early days so bear with me. Right I have a on going problem with the the power tripping at home , i have had a new RCD consumer installed to try and help the problem, if anything it has made it worse. Ive had several electricians around, one from EDF to check and reinstall the supply cable, one increased the fuse to i think 100ma and the most recent one changed the meter. All this has seemed to make it worse. the RCDs normally always both can trip 10-20 times a day now. Futhermore now sometimes when it trips and i reset them the power doesnt come back on at all, even though they are all in the 'ON' position. After doing some research myself I found that if the RCDs are changed to RCBOs this should help solve the problem? I understand that the RCBOs are MCBs and RCDs combined. But If this is so are they generally less sensitive then RCDs otherwise this might not help the problem? Do i need a specific board to use RCBOs or can i replace the RCDs directly? Please can someone help!
Before anyone says im not going to attempt to do this myself, i will have a qualified sparks carry the work out.
cheers Greig

 

[robskiing]

Whats your location be better if someone off the forum near to you had a look and advise you on your next course of action hard to tell just by reading your thread

 

[white armour]

Hi niceandripe, is there any particular time or occasion when the RCD trips? A little bit more info about when it happens may help shed a little light on things, other than that agree with rob above.

Regards wa

 

[madrid]

could be one of many things see below

1) Nuetral earth fault

2)Neutrals connected to the wrong neutral bar in board.

3)borrowed neutral on lighting circuit

4)Live to earth fault.

5)about a dozen other things

When it trips switch all mcb's off and reset rcd.switch mcb's on one by one and operate equipment on each circuit as you go.sooner or later the rcd will trip and that way you can narrow down the fault to the circuit concerned.replacing the board with an all rcbo board will cost a few bob and is surely avoidable.

 

[niceandripe]

hello thanks for the replies, it happens at any given moment, yesterday when opening the microwave. when nothing is being switched. Next door have been drilling and that also makes it trip! Doesnt anyone think replacing rcds with rcbos would help?
I read this online - If several devices of this type are fed from a consumer unit with only incoming RCD protection, it’s not long before the leakage currents add up to very close to the tripping current of the RCD. In this situation, regular nuisance tripping is virtually inevitable. Feeding individual circuits with separate RCBOs is, once again, the answer.
Can anyone give me any more advice on RCBOs and can they be directly fitted to a RCD CU?
Ive had half a dozen electricains come round all costing time and money and the problem still remains, so im looking for online help atm
Cheers

 

[timo1]

You could save yourself some money by getting some RCBO'S from ebay. Wylex ones are normally about £12 each compared with £25 or more at a wholesalers. The benefit of an RCBO will mean that only the circuit on the fault on would trip as opposed to several circuits that are controlled by an RCD.

Has it always been like this or did something happen to make it worse? It would be best to get someone to do a PIR (periodic inspection report) and this will give an idea to the faults as if you have faults on the circuits then an RCD will never hold as it is doing its job by detecting a fault. I can only agree with what has been said, if you post your location I'm sure someone from the forum could help.

 

[timo1]

RCBO'S can sometimes be fitted to an RCD board depending on the boards configuration. If you take a photo of your consumer unit then it will be easier to advise.

 

[telectrix]

the money spent on buying RCBOs would be better spent on an electrician who can fault find. there is quite probably more than 1 fault. it's not a 5 minute job. all circuits need IR testing, any borrowed neutrals finding, as said previously. if you post your location, there is probably a forum member close to you, to have a look and advise accordingly.

 

[mickys86]

hello thanks for the replies, it happens at any given moment, yesterday when opening the microwave. when nothing is being switched. Next door have been drilling and that also makes it trip! Doesnt anyone think replacing rcds with rcbos would help?
I read this online - If several devices of this type are fed from a consumer unit with only incoming RCD protection, it’s not long before the leakage currents add up to very close to the tripping current of the RCD. In this situation, regular nuisance tripping is virtually inevitable. Feeding individual circuits with separate RCBOs is, once again, the answer.
Can anyone give me any more advice on RCBOs and can they be directly fitted to a RCD CU?
Ive had half a dozen electricains come round all costing time and money and the problem still remains, so im looking for online help atm
Cheers

Seems strange to me that "Half a dozen electricians" can't find the problem

 

[telectrix]

if it was tripping before the RCD/s were fitted. what was tripping? fuse, MCB? several visits by EDF can only find problems up to the house, not on the installation itself.can't see how whoever fitted the new CU didn't test and find the fault/s.

 

[electromonkey]

Hi Niceandripe,
As said above, replacing MCB's for RCBO's is unlikely to solve your problem of nuisance tripping. Testing all circuits above may help but wont necessarily give you the answer. Have you any problems with damp in the property? I'd be willing to wager that it could be a straight forward problem like a loose connection in one or more of your sockets.

 

[niceandripe]

Hello the guy who fitted the CU found a fault and uprated the fuse, then the problem come back.
The board is E M M A bsen 60439-3, will RCBOs fit into this? Thanks!

 

[telectrix]

whilst they will fit in, fitting RBOs won't cure the problem. waste of money trying. like putting a bandage on a severed artery. you need to get the fault found and sorted. this will require the correct test gear ( MFT or Insulation Tester ). and the knowledge to use it.

 

[Engineer54]

Whilst i agree with Telectrix in many respects here, i'm not keen on split CUs at the best of times, i much prefer an RCBO CU's!! ...Yes there more expensive, but any faults are always going to be limited to the individual RCBO circuit the fault is occurring on....


Getting back to this threads matter, ....it seems that there has been a lot of activity from various electricians inputs that have achieved little to nothing. It's sad to hear that there can be half a dozen sparks in this area, that have no fault finding expertise. Let's face it, domestic installations ain't exactly rocket science. The problem is, the O/P managing to find an electrician that CAN and does know how to fault find basic domestic circuitry!!!!


So, in this case i fully agree with the suggestion that he tries to secure the services of an electrician from the forum, that lives or covers his area. Hopefully, this will be the last electrician this guy will need to employ for a long time to come... lol!!!

 

[Geoffsd]

Is it possible that the absence of a main switch, whilst not, in itself, a cause of the problem, might indicate that the CU may not be wired correctly?

Also, if I have read the next inspection date of Dec. 17 correctly, this would indicate that the CU was fitted three and a half years ago.
Has the tripping been happening for all this time? As the installer has used a NICEIC sticker why did you not keep getting him back until the problem was solved?

Although why nobody seems capable of finding the cause is a bit odd.