Socket ring circuit extended by me, RCB now trips

JMSE

Hi folks, I'm after extending the upstairs ring circuit in my 1983 3 bed semi.

I installed 5 more double sockets in the teenagers room and 3 more in the boxroom. Some of these doubles have USB charging points in them. I stayed fairly true to whats required for spurs, i.e. no more than one spur per socket on the ring? I used a few junction boxes when it was necessary, the new USB sockets are a tight fit and theres no way I could get 3 cables into those in the limited space so if a particular USB socket wasnt a spur, I still only brought one cable to it from a junction box.

Also removed the old ceiling pendant/rose in the boxroom and installed 2 new wall lights instead. These are Class 1 so I needed to bring an earth into the lighting circuit where there wasnt one before. I brought a sheathed earth wire from one of the junction boxes mentioned above across to the nearby 'lighting junction box' where I was splitting the Line to go to 2 separated wall lights.

Although I had both the lights and socket circuit trip switchs in the off position, the rest of house was live. So anytime while I was wiring I crossed wires the RCD would trip. That was expected so I tried to avoid but it happened, and it was good to know that it was working too.

So I tried the lights the other night, no problem. Last night I finished the socket circuit job but when I went to reset the trip and power up the circuit, the RCB tripped.

Am in the process of going back around everything to see where I've crossed wires (but I dont expect to find this).

Anyone have any spotlights to shine on where they think I might be making common mistakes? Do these USB sockets have issues with RCBs?

Thanks for reading....

Risteard81

Is the installation north or south of the border?

JMSE

Risteard81 wrote: »

Is the installation north or south of the border?

????

Risteard81

I doubt I can clarify my question any further. Whereabouts in the country is the electrical installation?

JMSE

Risteard81 wrote: »

I doubt I can clarify my question any further. Whereabouts in the country is the electrical installation?

Meath risteard

Risteard81

OK. By spurs are you referring to unfused (aka non-fused) spurs?

JMSE

Risteard81 wrote: »

OK. By spurs are you referring to unfused (aka non-fused) spurs?

Yes unfused spurs

Risteard81

OK. ET101:2008 incorporating Amendment No. 1 (2011) and Amendments 2.1 and 2.2 (ETCI National Wiring Rules) does not permit non-fused spurs from a ring final circuit.

JMSE

Risteard81 wrote: »

OK. ET101:2008 incorporating Amendment No. 1 (2011) and Amendments 2.1 and 2.2 (ETCI National Wiring Rules) does not permit non-fused spurs from a ring final circuit.

Does my rcd know that?

Risteard81

I haven't got to that bit yet. But you claimed to have stayed fairly true to the rules for spurs from a ring circuit which clearly is untrue. So now we have to establish what actually has been done. It seems clear that it is a wiring fault.

JMSE

Risteard81 wrote: »

I haven't got to that bit yet. But you claimed to have stayed fairly true to the rules for spurs from a ring circuit which clearly is untrue. So now we have to establish what actually has been done. It seems clear that it is a wiring fault.

In the process of rechecking all

Risteard81

As always I would strongly advise the use of a Registered Electrical Contractor (REC).

JMSE

Risteard81 wrote: »

As always I would strongly advise the use of a Registered Electrical Contractor (REC).

Will do thanks. I did ask one to do the job, I agreed to run the cables first. He said he would drop a roll of cable to me.... And never did. In the end I bought my own stuff from CWE and stayed at it. I don't claim to be up to speed on regs, But for this type of stuff I do a fairly neat job so am confident up to a point.

Doolittle51

One of the cables may have come loose or was pinched when you screwed on the sockets.
Did you sleeve the earth conductors?

Are you sure it was ring circuit? What size is the MCB? It's not really a ring circuit anymore if you've added a lot of spurs so the safest option is to change the MCB to 20A.

JMSE

Doolittle51 wrote: »

One of the cables may have come loose or was pinched when you screwed on the sockets.
Did you sleeve the earth conductors?

Are you sure it was ring circuit? What size is the MCB? It's not really a ring circuit anymore if you've added a lot of spurs so the safest option is to change the MCB to 20A.

Am onto something now, I had wanted to remove a cable between two sockets and extend the previously tiny ring (just 3 sockets). In error I disconnected one of those sockets from the fuse board and the other socket from its neighbour. Going to fix what I can see is wrong and take it from there.

To answer you Doolittle, I have 6 Spurs out of 16 sockets in the ring. I've sleeved the earths, mcb was already 20amp, rcd was tripping with no load though.

JMSE

That's done, problem still there. I flip the switch to power the circuit and the RCD immediately trips

eurokev

What type of cable did you use, twin and earth? Check at points where you stripped back the cable, you may have damaged insulation and it is now touching off the unsheathed earth. I did this before myself.

eurokev

A ring socket should be on a 32A MCB also fyi

JMSE

eurokev wrote: »

A ring socket should be on a 32A MCB also fyi

I used 2.5mm2 twin and Earth. Sheathed the earths. Have visually checked all JBs and sockets. There's nothing plugged into any of them when I try to reset the Rcd so would changing the mcb be a suspect at all?? What's the likelihood any electrician won't hang up when I tell him what my problem is...

brightspark

Try replacing the USB outlets with normal ones.

(It goes without saying that you have broken the law and probably invalidated your house insurance etc.)

JMSE

brightspark wrote: »

Try replacing the USB outlets with normal ones.

(It goes without saying that you have broken the law and probably invalidated your house insurance etc.)

Being a driver by trade I'm well used to being an outlaw daily. Then you have pubs crammed an hour after closing every weekend. I don't loose a whole lot of sleep over this stuff but thanks.

JonnyM

At a guess I think it's the usb sockets. Possibly the small traffo in the usb socket.
It may only be 1 of the new sockets you installed. You could try taking a usb socket out of the circuit 1 by 1 and when you have taken the socket out of the circuit try reset the rcbo.

2011

JMSE wrote: »

I installed 5 more double sockets in the teenagers room and 3 more in the boxroom. Some of these doubles have USB charging points in them. I stayed fairly true to whats required for spurs, i.e. no more than one spur per socket on the ring?

As has already been stated the ring circuit should have been maintained or the spur should have been fused. Best practice would be to install an additional socket circuit.
This will mean that every socket on the circuit will have two cables, making it relatively easy to connect.

I am not a fan of ring circuits, there is far more potential for something to go wrong.
If I was the electrician doing this I would turn the ring into two radial circuits (each fed from a 20A MCB) and I would install a fresh circuit for the additional sockets.

I used a few junction boxes when it was necessary

The use of junction boxes is considered bad practice and should be avoided if at all possible.
Remember ever join is a potential point of failure.
If a junction box is used it should be accessible.
What you want to avoid is a junction box under the floorboards smouldering away, especially when it is on a 32A MCB :eek:

Remember a 32A MCB will not trip at 32A (it is not designed to).

the new USB sockets are a tight fit

This is not good as these devices can generate heat (just like mobile phone chargers, which is what they are essentially), the last thing you need is a fire hazard. Also cables can get crushed, which is not good either. It would be advisable to install a deeper back box.

and theres no way I could get 3 cables into those in the limited space

Three wires into one terminal would be inadvisable. If the circuit was properly thought out it would be unnecessary.

so if a particular USB socket wasnt a spur, I still only brought one cable to it from a junction box.

As above, this is against relations.

Also removed the old ceiling pendant/rose in the boxroom and installed 2 new wall lights instead. These are Class 1 so I needed to bring an earth into the lighting circuit where there wasnt one before. I brought a sheathed earth wire from one of the junction boxes mentioned above across to the nearby 'lighting junction box' where I was splitting the Line to go to 2 separated wall lights.

At least they have an earth, but this really is not the way to do it.

Although I had both the lights and socket circuit trip switchs in the off position, the rest of house was live. So anytime while I was wiring I crossed wires the RCD would trip. That was expected so I tried to avoid but it happened, and it was good to know that it was working too.

Shorting the neutral and the earth for the socket circuit should cause the RCD for the sockets to trip. However as the lights generally should not be on the socket RCD shorting lighting cables should not cause it to trip.

So I tried the lights the other night, no problem. Last night I finished the socket circuit job but when I went to reset the trip and power up the circuit, the RCB tripped.

I assume you mean "RCD".

This can happen when:
1) The lighting circuit is not fed from the socket RCD (which is normal) and the neutral for this lighting circuit is connected to the neutral of a socket circuit.
2) There is a short somewhere between earth an neutral.

Am in the process of going back around everything to see where I've crossed wires (but I dont expect to find this).

Normally this type of problem is solved with a process of elimination.

Anyone have any spotlights to shine on where they think I might be making common mistakes?

No offence, but I think you are out of your depth here.
Initially I thought that other posers were being a bit harsh, but now that I read your post throughly I don't think they are.
Remember you are dealing with a lethal voltage.
It is generally very simple to make domestic wiring "work", the skill is about making it work safely and if possible at a reasonable price.
I have answered your questions in the hope that you can gain some understanding when employing the services of a professional electrician, not that you attempt this yourself.
I don't want to be condescending, I would just rather that you and yours are safe.

Do these USB sockets have issues with RCBs?

No, but for safety reasons (as well as ease of installation) I would recommend using a quality make such as MK.

Risteard81 wrote: »

OK. ET101:2008 incorporating Amendment No. 1 (2011) and Amendments 2.1 and 2.2 (ETCI National Wiring Rules) does not permit non-fused spurs from a ring final circuit.

JMSE wrote: »

Does my rcd know that?

As you seem to have spotted this particular breach of the wiring regulations will not cause an RCD to trip

JMSE

Thats comprehensive 2011, thanks! I'm being honest when I say I wanted a pro to do this for me, I just then couldnt stop myself when I should have obviously. I take all those points on board. Theres a phone number I need to ring today . (All that said, even though theres a short between earth and neutral somewhere, I'm fairly proud of my standard of actual wiring at each point, some of it is almost dang pretty - please nobody jump in and say pretty is against regs )

Regards.

Stoner

OP, this work requires that you use a registered electrical contractor. I'm going to have to close it as it won't be allowed to develop any further for you.

There is a list of contractors in the sticky and charter.

2011

Thread reopened.

Please read the updated Forum Charter before posting.
Thank you.