Are broken breakers safe?

[Deadeye]

I have an electrical fault (my wife would argue several).
This one is a breaker permanently tripping on a ring of sockets.
I've had the fronts off all and checked the wires are in firmly. I've also checked the cables (they are in the ceiling and I can get in the roofspace; just). All looks ok, but even with all the sockets off, the breaker won't stay on.
Might the breaker be broken? Would that mean it always defaulted to off?
Other ideas?
Or do I need to wait for electricians to become available once more?

 

[jimmy_s]

Presuming its a MCB rather than a RCBO? could be faulty device. Also check in case anything has been spurred off the ring cct such as a boiler or a fan etc.

It might be worth buying a replacement and just swap it over, if its just a MCB they are generally quite cheap.

Do you have a multimeter?

 

[porker]

When you say breaker, I am assuming you have MCBs on each circuit and one of these is tripping? Or is this an RCD tripping a group of circuits caused by earth leakage? It could also be an MCBO which are less common on older installs that could trip due to either overcurrent or earth leakage.
Breakers can go faulty but it is more likely you have a real fault.
There are some things you can do (safely) to narrow down what might be the problem but turn the power off first. If it is an overcurrent breaker and I suspected a faulty breaker I would turn off the CU and swap another breaker of the same current rating into the slot where you are having the problem. If that trips then you have a fault.
Sorry if I am making wrong assumptions but being as you had to ask I would say get an electrician in. They will have a tester that should be able to narrow down the fault.

Please don't open the CU unless you know what you are doing.

 

[Rorschach]

Electricians are still available, get one in, don't mess with it yourself.

 

[mbartlett99]

Breakers do break - I've had replace two this week and they were less than 10 yrs old - but not generally as you describing ie tripping with no load at all. They are safe in as much as they've opened but not a lot of good in that state.

Do you access to an amp clamp or even a decent multimeter? If so, with the breaker 'off', test for resistance to ground from the load side to ground. Or with the amp clamp measure amperage when you close the breaker but with all sockets off.

 

[Deadeye]

Thanks everyone! Still here and not fried!

It's a 30mA CUCRB20
It's a set of sockets (6) in series; I'm not messing about in the CU (after all, Clint did say "a man's gotta know his limitations")

Sounds like time for a pro. Thanks again everyone.

 

[nev]

I have an electrical fault (my wife would argue several).
This one is a breaker permanently tripping on a ring of sockets.
I've had the fronts off all and checked the wires are in firmly. I've also checked the cables (they are in the ceiling and I can get in the roofspace; just). All looks ok, but even with all the sockets off, the breaker won't stay on.
Might the breaker be broken? Would that mean it always defaulted to off?
Other ideas?
Or do I need to wait for electricians to become available once more?

Disclaimer: not a certified electrician.
Did you unplug everything from all the sockets? or just switch them off?
Turning a socket off only disconnects the live terminal leaving the earth and neutral connected. If something plugged into a socket has a neutral/earth fault it may still be detected by the RCD and trip.
Fridges/freezers and irons are the usual suspects.

 

[HappyHacker]

Thanks everyone! Still here and not fried!

It's a 30mA CUCRB20
It's a set of sockets (6) in series; I'm not messing about in the CU (after all, Clint did say "a man's gotta know his limitations")

Sounds like time for a pro. Thanks again everyone.

That is an RCBO which apart from being a MCB (20A ) and a 30mA RCD in one unit. It is probably the RCD bit that is tripping with a fault to earth. Unplug everything that is on that circuit and see if it still trips. As If it still trips it can be a faulty RCBO, a faulty appliance on the circuit that you have not yet found or a fault in the wiring. External lights, central heating pumps, ovens, fridges are amongst the most usual appliances that cause problems. As has been said turning the sockets off does not always disconnect the neutral and a Neutral - earth fault in the wiring or appliance can cause a trip.