Wiring query

[jstrong]

I need to move my consumer unit to an opposite wall as the wall it's on is going to be demolished and therefore I need to extend all the rings and radials. An electrician said the best thing to do would be to put a bank of junction boxes within the ceiling void with a trap door. Here's the query, The first ring I worked on was the first floor power circuit, I've taken the two supply cables from the CU which fed the FF ring and connected both these cables in a 3 terminal junction box with the two ring cables leading from here and returning to the same JB.

The ring worked briefly but is now no longer working, the RCB that feeds this ring isn't tripping but there doesn't appear to be any current when checked with a neon!

Was I wrong to connect all four ring cables in one junction box i.e. the two that come from the RCB and the two that supply the ring? Should I have had one cable from the RCB going into one junction box and then the ring starting from there and returning to a second junction box with a cable returning to the RCB from there?

Would using just one Junction box cause a fault in the RCB?

I just need to know the correct procedure for extending these rings and what has caused the RCB to malfunction?

Thanks for any guidence before I get the electrician to do the actual reciting.

 

[roderz]

Junction boxes !!
I'd go for DIN rail mounted blocks + enclosure.
Google DIN rail mounted blocks

 

[bernardgreen]

An electrician said the best thing to do would be to put a bank of junction boxes within the ceiling void with a trap door.

But the "electrician" didn't tell you the details of how to make the connections ?

You need two junction boxes per ring if you do this method. What you have done is created a figure 8 circuit.

Loss of power ? What size junction box did you use ? 10 amp. 30 amp 60 amp ? Has it melted or charred ? are the screws tight. New cable to the MCB ? Isi properly connected to the MCB terminals.

Neons ( assume a neon screwdriver ) indicate only the person holding it and the metal it is touching are more than 100 volts different in potential. They can light when touching an earthed piece of metal if the person is close to some live wires such as a light switch. Throw it in the bin and get at the very least a multi-meter.

Sorry but you appear to lack the necessary knowledge to do this work in safe manner. Find an electrician who will replace the cables from end of ring sockets to the consumer unit and thus avoid the need to have junction boxes.

 

[ban-all-sheds]

You've energised the circuit - could you scan and post your schedule of test results?

Or tell us what readings you got for continuity and IR?

Was the electrician who gave you some vague advice and then left you completely to your own devices the one you got following on from this:

Thanks for all the advice and guidence, I shall now contact an electrician and ask him to prepare a design with agreed intervals of inspection before finally signing off.

Thanks again.

?

 

[jstrong]

ban all sheds
I am trying to do as much of the donkey work as possible, the electrician will be doing the kitchen wiring, I am just creating a bank of JB's for the electrician to connect to for the rest of the house.

 

[HERTS P&D]

Even though this is a DIY site, some jobs need to be done by a tradesman. This is one of them.

Andy

 

[jstrong]

In response to my first post all is now well! I have used two seperate JB's, one for out going and one for the return.

The power circuits are on B32's can I use 20amp JB's and 5amp JB's for the lighting radials?

 

[ban-all-sheds]

You have to ask your electrician.

He is going to be putting his professional reputation on the line by signing a declaration to say that the design of the installation complies with BS 7671, and that he exercised reasonable skill and care when doing it.

Nobody may make design decisions on his behalf - not you, and not us.

 

[seasickstevie]

... two seperate JB's, one for out going and one for the return.

Which is which?


Clue: Is there a difference?

 

[bernardgreen]

The power circuits are on B32's can I use 20amp JB's and 5amp JB's for the lighting radials?

Is 32 greater or less than 20 ?

32 amps through a 20 amp terminal ?

And yes if there is a fault on the ring then the entire 32 amps ( 8 kilowatts ) or 24 amps ( 6 kilowatts ) could have to go through one of the two junction boxes.

I assume your "electrician" is on holiday and cannot advise you on how to do the work he (or she ) will have to sign off as compliant.

 

[jstrong]

Thanks for the replies.

The JB's are a temporary measure until I get the time to extend the rings correctly.

30 amp JB's for power and 5amp for lighting it is then.

 

[ban-all-sheds]

32 amps through a 20 amp terminal ?

20A is considered an acceptable Iz for the cables being joined there.....

 

[jstrong]

ban all sheds

Thanks, it's ok to use 20amp then, and 5amp for the lighting radial? if that's safe i'd prefer that as 30's are a bit bulky for the space.

thanks again

 

[sparkwright]

It is the norm to use 30 amp junction boxes on ring circuits.

Instead of b o l l o x i n g around joining these cables without knowing what you're doing which you now tell us is a temporary measure, why don't you just get the electrician who's doing the rest of the job to do it?

No offence.

 

[RF Lighting]

There is no electrician is there?