30A Junction box

[ban-all-sheds]

Nobody has asked where the cable was.


If, for example, it's running diagonally in a wall, or meandering about, then even joining it behind a socket or blanking plate won't do, and re-routing would be required.

//www.diynot.com/wiki/electrics:walls

 

[psarinuk]

If so and both are damaged, you can cut both sets and fit in to back box, you must connect one leg back together, so identify that leg. Then the other leg can be fitted to a socket.

This is what I understood. I was just trying to see if I can avoid connections. So a connection would be required on one leg. Fine!
Does it matter which one is connected from the two and which one is fed to a socket?

The addition of the socket could flag up issues with regards to additional RCD protection if not already existing on the circuit.

Not sure how you mean. There is RCD protection for the ring main at the consumer unit. I think its the 32A one. The total number of sockets on the ring main are far far less than 30. Am I missing anything?

Nobody has asked where the cable was.

The cables are in a SOLID wall in a VERTICAL metal conduit pipe.

 

[OwainDIYer]

The cables are in a SOLID wall in a VERTICAL metal conduit pipe.

So you've cut through a conduit?

Then you will need to reinstate the conduit which must be continuous, or terminate the conduit each side of the break with boxes having an earth terminal and bridge the gap with an earth wire, to ensure that both parts of the conduit are earthed.

 

[psarinuk]

So you've cut through a conduit?

NO, I've cut a small front section with an angle grinder to take look, so most of the conduit is intact.

Can someone please advise if I need to be careful about which of the 2 ring main cables should be used for a socket and which one left continuous. Is there like a forward and return leg or does it not matter.

Thanks.

 

[ban-all-sheds]

Then you will need to reinstate the conduit which must be continuous, or terminate the conduit each side of the break with boxes having an earth terminal and bridge the gap with an earth wire, to ensure that both parts of the conduit are earthed.

The latter might not be acceptable, as mechanical protection might be mandatory.

We still do not know where the cables were running.

 

[ban-all-sheds]

So you've cut through a conduit?

NO, I've cut a small front section with an angle grinder to take look

[gobsmack]WTF did you do that???? [/gobsmack]

 

[flyingsparks]

I'm getting confused now as to what the op has done. We definitely need photos! Are the cables singles in galv conduit and he's drilled into it, so now cut a chunk out to look inside to see the damage?

 

[OwainDIYer]

Then you will need to reinstate the conduit which must be continuous, or terminate the conduit each side of the break with boxes having an earth terminal and bridge the gap with an earth wire, to ensure that both parts of the conduit are earthed.

The latter might not be acceptable, as mechanical protection might be mandatory.

Yes.

I was thinking solely of maintaining the earth continuity to both ends of the conduit, which might not be earthed at the other end.

Mechanical protection of the circuit cables may be required in addition.

 

[ban-all-sheds]

I've accidentally drilled through the 2.5mm ring main of the house inside a wall...

Nobody has asked where the cable was.

The cables are in a SOLID wall in a VERTICAL metal conduit pipe.

So you've cut through a conduit?

So at this point, the sequence was quite clearly

"I drilled through a cable"
"Where was the cable"
"It was in conduit in the wall"
"So you've cut through a conduit?"

And the answer he gave was no, i.e. he had not drilled though it, he'd cut it with an angle grinder to see what was inside.

 

[psarinuk]

I am at work, so don't have photos.

I've drilled into a wall with a vertical metal conduit holding 2 of 2.5 mm twin & earth ring main.

To look at the damage, I cut a small rectangular section (with house's main electrics OFF) of the metal pipe holding the cables.
Can you imagine a metal pipe with a small window in the middle?

I am now inclined to cut off the two cables and pull them out of top opening of the conduit (as I have access). Then route them from outside the wall as it's a pantry with a door, so won't be visible.

Where the wires have been cut, I plan to put a dual surface pattress. Connect one of the cables with a choc box in the pattress and cover with a blanking plate. The other end of this cable would be new cable running to the other end (can be accessed).

The second cable would be turned into a unswitched spur socket for my alarm control panel (which is what I intended to do in the first place).

The only thing is I plan to run a 20mm plastic conduit for the cables now on the outside of wall.

Hope this is OK.

 

[ban-all-sheds]

I am at work, so don't have photos.

I've drilled into a wall with a vertical metal conduit holding 2 of 2.5 mm twin & earth ring main.

So you DID drill through conduit.

How on earth did you manage that without noticing it was there?

You do mean steel conduit? Not capping?

I am now inclined to cut off the two cables and pull them out of top opening of the conduit (as I have access). Then route them from outside the wall as it's a pantry with a door, so won't be visible.

Where the wires have been cut, I plan to put a dual surface pattress. Connect one of the cables with a choc box in the pattress and cover with a blanking plate. The other end of this cable would be new cable running to the other end (can be accessed).

The second cable would be turned into a unswitched spur socket for my alarm control panel (which is what I intended to do in the first place).

No - you must re-join each cable as it was, or you will no longer have a ring.

 

[psarinuk]

Don't ask how I managed that. virtues of a good drill i think.

Can't forgive myself for this.

I m going to take the advice of adding a socket with one cable and continuing the other cable as ring.
Also going to add new cables for one side of this mess.

Thx to all for their help.

 

[PrenticeBoyofDerry]

Nobody has asked where the cable was.


If, for example, it's running diagonally in a wall, or meandering about, then even joining it behind a socket or blanking plate won't do, and re-routing would be required.

I wonder how many electricians or even non-electricians, when doing repair work to a damaged part of a circuit, would actual determine where the existing cable is routed when it is buried within a wall?