Socket outlet connected to 2 circuits
- Thread starter Mikey_A
- Start date
I was spuring off a downstairs socket outlet to supply an outdoor socket outlet.
I didn't want to isolate the whole house so i decided to remove the mcb that was protecting that circuit, 32a.
Once i removed the mcb I tested the outlet and i was still getting 230v. I thought i'd removed the wrong mcb. The only other mcb that would be supplying sockets was a 16a mcb.
So, i put the 32a mcb back in and removed the 16a mcb. Tested the socket outlet again and it's still live reading 230v. It only became dead when i removed both the 32a & 16a mcb.
I didn't want to isolate the whole house so i decided to remove the mcb that was protecting that circuit, 32a.
Once i removed the mcb I tested the outlet and i was still getting 230v. I thought i'd removed the wrong mcb. The only other mcb that would be supplying sockets was a 16a mcb.
So, i put the 32a mcb back in and removed the 16a mcb. Tested the socket outlet again and it's still live reading 230v. It only became dead when i removed both the 32a & 16a mcb.
Sounds like a cross connected ring. This needs to be put right as there is a potential to overload the circuit cables, and also the problem of isolation
It's my Nans house and I know for sure that apart from a chairlift and shower being installed there have been no other alterations, especially to the ring circuits. Both the chairlift and shower are on there own circuits.
I'm just wondering - is it possbile that the 32a mcb should be supplying the downstairs ring and the 16a should be supplying the upsatairs ring. But the return phase on the circuit protected by the 16a mcb has been terminated in the 32a mcb and the return phase on the circuit protected by the 32a mcb has been terminated in the 16a mcb?
I'm just wondering - is it possbile that the 32a mcb should be supplying the downstairs ring and the 16a should be supplying the upsatairs ring. But the return phase on the circuit protected by the 16a mcb has been terminated in the 32a mcb and the return phase on the circuit protected by the 32a mcb has been terminated in the 16a mcb?
Sounds like it may be, or upstairs may be a radial circuit with one leg of ring being terminated into the 32 MCB along with the radial circuit, and the other leg of the ring ending up in the 16A MCB.
Just becuase it hasn't been modified, doesn't mean it was done right to start with
Just becuase it hasn't been modified, doesn't mean it was done right to start with
unfortunately this (potentially lethal) mistake does occour with some frequency.
Usually, in my experience, it is that two seperate rings are cross connected at the consumer unit.
Picture the scene.
Two rings each with two outgoing legs or so you think but unfortunately one leg of each ring connected to one OPD (Fuse/MCB) and the other leg of each ring connected to another fuse/MCB.
Each ring is fed off two outgoing ways which give no isolation from a single device (Isolation is not the correct term but for illustration purposes here) and each ring has an unusually large overcurrent protection during earth fault , short circuit or overload conditions.
You appear to have this problem (or a variation of it)
Usually, in my experience, it is that two seperate rings are cross connected at the consumer unit.
Picture the scene.
Two rings each with two outgoing legs or so you think but unfortunately one leg of each ring connected to one OPD (Fuse/MCB) and the other leg of each ring connected to another fuse/MCB.
Each ring is fed off two outgoing ways which give no isolation from a single device (Isolation is not the correct term but for illustration purposes here) and each ring has an unusually large overcurrent protection during earth fault , short circuit or overload conditions.
You appear to have this problem (or a variation of it)
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ebee said:
Usually 50Hz.
Rectified this problem today. The return phase of the ring was terminated in a 16a MCB which was supposed to be for the combi boiler circuit and the combi boiler phase was terminated in the 32a MCB protecting the ring.
RF Lighting said:
Do I get a gold star?
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