hi. can anyone tell me how to find a fault within the ring circuit for the sockets only, i think we have had a rodent chew through the main cable which on my house supplies both upstairs and downstairs sockets (bieng a concrete floor) 1 trip switch turns off both up and down stairs. i am not sure which way the ring is wired. the first socket nearest the fuse board in the hall is ok as is the socket in the living room behind the hall socket, 1 socket in upstairs bedroom works if i remove 1 red wire???. any suggestions
mains ring circuits
- Thread starter steve16
- Start date
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If it is a ring and removing ONE wire from a socket that has two wires apparent "clears" the fault then you have two faults in the circuit. The short circut that is causing the trip to trip and another break in the ring. ( they could be at the same place )
Best advice for you is to get an electrician to find the fault and repair as necessary.
Best advice for you is to get an electrician to find the fault and repair as necessary.
Is the MCB tripping
Is the RCD tripping (do you have an RCD?)
i.e Tell us what it says on the device that you switch off to cut the power to the circuit.
Is it only one socket that works if you remove the single wire? (and is the single wire live when removed?)
Do some sockets work and others dont?
For a socket on a ring not to work you should expect TWO faults.
Is the RCD tripping (do you have an RCD?)
i.e Tell us what it says on the device that you switch off to cut the power to the circuit.
Is it only one socket that works if you remove the single wire? (and is the single wire live when removed?)
Do some sockets work and others dont?
For a socket on a ring not to work you should expect TWO faults.
To eloborate, and maybe educate.
A finale ring circuit consists of a cable that originates from a CU (consumer unit / fuse board) fuse position (the cable is normally 2.5mm twin and earth TE), goes out and round various sockets and then returns to the same fuse position.
So power travels down both cable paths and as such one complete break would split the circuit in to two parts. Since the power travels along both cables, one brake would not appear obvious to a user.
Rats tend not to be small enough to get in to a socket back box, so if rats have meddled with a cable the only way this would be evident is if the rat in question has shorted any of the cores of the cable with each other causing circuit failure. A complete break is unusual, since the rat will go 'fizz, pop' when it gets 230v
If you have a socket that doesn't work then that could be something entirely different.
As for faulting a ring circuit, that's easy if you have access to a decent continuity tester and have the skills to remove the fuse board cover, isolate the board and circuit and carry testing.
End to end testing of each wire will determine if there's continuity r1, rn and r2 (live, neutral and cpc / earth),
If, on the above test a fail is noted, then continuity across the cores is tested at the sockets having opened the ring and joined cores together to provide a loop.
It might help if you explain (as others have asked) why you feel it's a rat issue, and what symptoms have you noted ?
Consider things like any DIY drilling done recently, water in sockets, damp, humidity, ageing fittings, aged wiring...
A finale ring circuit consists of a cable that originates from a CU (consumer unit / fuse board) fuse position (the cable is normally 2.5mm twin and earth TE), goes out and round various sockets and then returns to the same fuse position.
So power travels down both cable paths and as such one complete break would split the circuit in to two parts. Since the power travels along both cables, one brake would not appear obvious to a user.
Rats tend not to be small enough to get in to a socket back box, so if rats have meddled with a cable the only way this would be evident is if the rat in question has shorted any of the cores of the cable with each other causing circuit failure. A complete break is unusual, since the rat will go 'fizz, pop' when it gets 230v
If you have a socket that doesn't work then that could be something entirely different.
As for faulting a ring circuit, that's easy if you have access to a decent continuity tester and have the skills to remove the fuse board cover, isolate the board and circuit and carry testing.
End to end testing of each wire will determine if there's continuity r1, rn and r2 (live, neutral and cpc / earth),
If, on the above test a fail is noted, then continuity across the cores is tested at the sockets having opened the ring and joined cores together to provide a loop.
It might help if you explain (as others have asked) why you feel it's a rat issue, and what symptoms have you noted ?
Consider things like any DIY drilling done recently, water in sockets, damp, humidity, ageing fittings, aged wiring...
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In the absence of any obvious reasons (recent DIY etc) then I would isolate the circuit and check every connection at every outlet.
If all seems ok then it could be rodent damage or a hidden junction somewhere.
If all seems ok then it could be rodent damage or a hidden junction somewhere.
Probably worth checking every socket for loose and/or burnt wires.
Even if you find and fix the problem, some people recommend a Periodic Inspection Report (PIR) each time a house changes hands and every 10 years in between.
Even if you find and fix the problem, some people recommend a Periodic Inspection Report (PIR) each time a house changes hands and every 10 years in between.
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