Need advice with replacing old electrical terminal

[zenonithus]

Ok guys bad news for me. I looked under the floorboards and the wires for this run into the bedroom next door. So I would have to lift planks nailed in to view it. Trouble is I have the carpet fitters coming to do the bedroom tomorrow!! So worst case scenario can I just leave this wire in a terminal (placed under floor) and it should be relatively ok? What are the major downfalls leaving it in the terminal if its been like that for years?

 

[zenonithus]

pic of the wires. Are these grey ones used for anything specific? Cheers

 

[endecotp]

What do you think it is heading towards in the bedroom? Sockets maybe? Other junction boxes?
Unscrew any sockets and see what you find. How many cables going to them, for example.

 

[sparkwright]

You said you used a mains screwdriver to test with.

Can you tell which size circuit breaker or fuse at the consumer unit serves the old junction box?

It should be noted these mains screwdrivers are for guidance only and must not be relied on as they can give misleading results.

 

[zenonithus]

I think the white cables go into the plug sockets. My best guess would be this grey feeds into another round junction box in the bedroom under the nailed down floorboard. There are three double plug sockets only in that bedroom. Maybe they all feed into that? I'm thinking of lifting the board before they come, though cutting it as its a nightmare to put back again. You guys really think its that bad to leave the wire there?

 

[zenonithus]

You said you used a mains screwdriver to test with.

Can you tell which size circuit breaker or fuse at the consumer unit serves the old junction box?

It should be noted these mains screwdrivers are for guidance only and must not be relied on as they can give misleading results.

I just did a test with screwdriver. Read as live current, then switched off sockets on circuit breaker and the screwdriver didn't read anything. So definitely connected to plug sockets. It has to be via junction box no?

 

[Taylortwocities]

Could be, might not be.
As mentioned above, it could be something to do with the heating system. This may be fed from a socket circuit via a fused connection unit. It could be something els entirely.

What are the major downfalls leaving it in the terminal if its been like that for years?

The major downfall is that if the screwed connection fails, they can do that over time as the copper material of the cable is softer than the brass terminal screw.
That means that your nice new carpet has to be pulled up whenever (whatever it is) fails, to access the terminal block.

That is the main reason why Maintenance Free terminals are mandatory in these situations.

 

[zenonithus]

so would these wires feed directly into a socket or terminal junction? Here is a pic I took under the floorboard in the room. Down the bottom is where the wire is fed through the gap in wall. You can see some sort of white thing down there. Does it look like something?

 

[zenonithus]

Ok guys the carpet has been laid

So I'm going to just replace the junction box and leave it under the floor. Though can anyone explain the wiring in this junction box? Why is one of the black wire (in blue tape on the left) left out and both the ground wires put in the screw instead? The bare copper ground wires should not be screwed in correct? How should I put these wires in the new junction box? Cheers

 

[PrenticeBoyofDerry]

Cannot really explain anything, as you was instructed in earlier replies, testing of cable was required to establish what, where and why?
It seems that advise was ignored/overlooked.
There are a whole number of what could have beens, but without testing, everything else is guesswork.

I would say the black conductor has been taped to prevent it from accidentally coming in contact with other conductors to prevent any dangerous or potentially dangerous hazards.
As there was no other spare terminal. ideally this should have been terminated to a separate connector but still enclosed.

The bare copper wires are very very likely to be the circuit protective conductors (CPC, aka earth). They should have been sleeved green (back in the day) or green/yellow (present day).
And yes they should be terminated together so continuity is preserved of the CPC.

I hope you have not in anyway altered this for the worst, hopefully improved it?

It really should have been removed at upstream source, if possible.

 

[Taylortwocities]

Last Friday, before this all got so immediate, you were advised by Sparkwright

A maintenance free Hager junction box (20 amp) would be ideal.

Be certain you have safely isolated the supply to this old jb fully. If in doubt get an electrician in.

Sitting in front of a computer screen It is impossible to say what that JB is for, what it does or even if it is still in use.

Get a electrician in, you should have sorted this before the carpet got laid. Sorry, I don't have any sympathy.

 

[PrenticeBoyofDerry]

Yes you was also advised to get in an electrician in, if in any doubt. Which in this case there seems to have been plenty of doubt. That advice should have been acted on, before a carpet fitters was employed.
Do not want to sound rude or harsh, but why ask questions if the answers/advice are going to be ignored?

 

[endecotp]

Though can anyone explain the wiring in this junction box? Why is one of the black wire (in blue tape on the left) left out and both the ground wires put in the screw instead?

We don't know.
To understand it, you need to work out where the wires go.
Like we said days ago.
But you ignored our advice, and now it is too late.

 

[zenonithus]

Hey guys, thanks for the replies. I didn't ignore your advise as I spent most of the morning testing junction boxes I could access and trying to figure out the source of the wire. I though I found it in the hallway, so disconnected the wires from the JB only to find they were not the other end. I did manage to disconnect some cut off wires in the hallway JB that were still connected but just cut off. Though this whole electrical wire didn't come to mind until after I arranged to get the carpet fitted and by then time was against me to rip that floorboard up as I have a newborn baby sleeping in the flat below it's not the sort of thing I could do at 7am. Also I think I was worried about being charged for canceling the carpet guy. I totally wanted to get to the source of this wire. I can always pull up the carpet to get to the floorboard and re-kick it back. I will bring in an electrician either way as I don't want to mess further with this. cheers

 

[zenonithus]

Just to add the only two grey wires that came out of the room I disconnected and the wires in the living room JB still had current. There was one singular white wire coming out of the room next to the grey wires that went into its own junction box and connected to the toilet. I think this must be the source of the living room JB and there is probably another JB under that floorboard. Also one of the sockets in the room had grey wires.