Found one leg of ring main disconnected | on ElectriciansForums

Discuss Found one leg of ring main disconnected in the DIY Electrical Advice area at ElectriciansForums.net

input33

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My friend was moving into a new (to him) house and wanted to change a cracked socket, so I went to show him how - straight swap - seems straightforward. I'll call this socket A.

There are two sets of twin and earth in the back of the socket (as you'd expect), but one leg was wired into a chock block to blank it off and pushed into the corner. This seemed strange to me as it would break the ring.

I turned the power back on and tested both legs - there was power to the connected leg, but none to the disconnected leg.

I decided to check the other two sockets. One had both cables connected, and the other (Socket B) had the same chock block and disconnected leg. This leg was also dead. Additionally, this socket has a spur coming off it and feeding something else (which I think is non compliant if the ring is broken).

I then tested continuity and resistance between disconnected leg on A and disconnected leg on B. There was continuity on Live Neutral and Earth, and low resistance.

My question is why do you think this would have been left like this? An electrician probably wouldn't have done it as it would have made the spur non compliant?

The trunking for the spur is a poor job, badly cut and not straight, and the cable has been stripped with a knife and peeled back, rather than wire strippers (can tell by looking at it).

My thinking is that a DIYer without enough knowledge has been at it and I can reconnect it. Thoughts?
 
TL;DR
Disconnected leg between 2 sockets - continuity and low resistance on them. Can I reconnect?
Disconnected because there's a screw or nail through the cable possibly.

What's the rating of the MCB / RCBO in the consumer unit?

Does friend own or rent the house?
 
Disconnected because there's a screw or nail through the cable possibly.

What's the rating of the MCB / RCBO in the consumer unit?

Does friend own or rent the house?

There are no visible screws or nails in the walls anywhere, but I guess that doesn't rule it out.

It's on a 16A RCBO with 30mA protection.

I have connected it back up and all appears well, but reluctant to leave it.


He rents from a housing association. I've told him he may need to call them. They'll have done an EICR but possibly just sampled?
 
There are no visible screws or nails in the walls anywhere, but I guess that doesn't rule it out.

It's on a 16A RCBO with 30mA protection.

I have connected it back up and all appears well, but reluctant to leave it.


He rents from a housing association. I've told him he may need to call them. They'll have done an EICR but possibly just sampled?
It's OK on a 16 amp rcbo it's a radial now not a ring
 
So would you connect it or leave it disconnected
If you are not able to answer that question [and you are clearly having doubts about your actions] it would be best if you left it alone and as need be seek competent assistance. That competent person can then decide on the best way forward.
Speaking only for myself, I would not be happy to advise anything other.
 
There are no visible screws or nails in the walls anywhere, but I guess that doesn't rule it out.

It's on a 16A RCBO with 30mA protection.

I have connected it back up and all appears well, but reluctant to leave it.


He rents from a housing association. I've told him he may need to call them. They'll have done an EICR but possibly just sampled?
Are all 3 cores L(R1), N(RN) and E(R2) continuous? Have you done a 500v insulation resistance test on this disconnected leg R1 to RN and R1&RN to R2? What were the readings?
 
Are all 3 cores L(R1), N(RN) and E(R2) continuous? Have you done a 500v insulation resistance test on this disconnected leg R1 to RN and R1&RN to R2? What were the readings?
They are. I have not done a 500v resistance test as I don't have the equipment. I have only checked continuity with a multimeter (which isn't enough when I'm not certain there wasn't a good reason for disconnection). I think I'll leave it disconnected and get him to ask landlord to have it tested by an electrician.
 
It has been disconnected for a reason which is almost certainly a fault which results in the protective device tripping. The fact you have connected it and all appears well may not result in a permanent fix as it maybe an intermittent fault which may reoccur. At present it is not posing a danger as the protective device is only rated at 16A.
 
It has been disconnected for a reason which is almost certainly a fault which results in the protective device tripping. The fact you have connected it and all appears well may not result in a permanent fix as it maybe an intermittent fault which may reoccur. At present it is not posing a danger as the protective device is only rated at 16A.


Yes, think I will disconnect it again as the 16A protection makes it okay to leave it. Out of caution, check the Electrical Cert. All I've done then is swap a socket like for like (for mainly cosmetic reasons).

Thanks for the help all
 

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