trip switch on electricity blows

[Kassee]

My main trip switch on my electricity has blown twice recently, we are suddenly plunged into total darkness - and there doesn't seem to be any obvious reason for it. But both times it happened I was doing the ironing and my son was in the shower. And its night time with a few lights turned on etc. Would the iron and shower together cause this to happen, or what. Does anyone know ??

[jomifl]

An electric iron of itself woul not cause an overload trip as it would be about 4 amps or less and the main trip would be al least 40 amps. An electric shower plus something like an electric heater or immersion heater might possibly do it. Are you sure that it isn't the RCD that is tripping?

[Clanad]

First thing I'd do is check with your power supply company and see if they've been experiencing power surges. It's highly unusual for the main circuit breakers to trip.

Here in the U.S. we find that older circuit breakers can actually wear out. Sometimes it's due to the spring breaking or becoming corroded and the tension lessens or there may have been a defect in the manufacturing process that's just now showing up... I think that's unlikely, but a possibility.

Personally, I'd check with the supplier for any anomalies...

[Old_Geezer]

I think it unlikely that a combination of things being used would blow the circuit breaker. Sounds more probable that one of the appliances you had on at the time has an intermittent problem causing a spike on the supply. Maybe the iron, maybe the shower, or maybe something permanently plugged in that switches on occasionally, like a boiler or freezer. May need some detective work to find.

[jamesnan]

My iron caused the same problem, that was the only thing being used at the time, and it is the second iron that has caused the same problem. New iron for you I would think!

[Whickerman]

IF you're talking about your RCD tripping, you need to get that checked - it only happens with an electrical short and is a safety feature.

[johnk]

It's probably your iron tripping the RCD. Try ironing when no one else is around. Anything with elements in water could be suspect.

[buildersmate]

It isn't normal, though, for the RCD to be protecting ALL the circuits of the house. An RCD is generally connected to protect all the sockets, leaving the lighting circuits alone. The OP is saying the whole house is plunged into darkness.

[The Builder]

I agree with BM.........unless, it's a VERY new house built under the newer 17th edition Elec. Regs. The house may have had some electrical work lately which would have necessitated the whole thing being brought up to the new standards.
Sorry about all this waffle, but today, ALL circuits have to be RCD protected.
Kassee ....... perhaps you have an RCD as your main incomer switch?

Anyway, back to the plot. Assuming it's an RCD that's tripping out, most likely to be earth leakage. Elec cookers, and freezers are the most common causes of "nuisance tripping". During their normal use, they leak a small current to earth ........ sometimes enough to cause a 30ma trip to operate.

I had this recently. I did a test on their RCD, and it was operating at around 20ma instead of 30ma. I just replaced the RCD and all was fine.

Of course it could still be the iron. Process of elimination. Has it tripped without ironing?

[Kassee]

Thanks for all your answers. Not sure what an RCD is - but we are not a new build. We have all electrics on separate circuits - light switch, elec. points etc etc, all can be turned off separately, and then we have an outside trip switch which turns the whole lot off - and it is this that went. We just went back outside and turned it back on again - but nothing had blown - so not sure why it went off.
The electrics are probably about 20 years old - as had it rewired then.

[AlBags]

Isolate stuff to find out what circuit it's blowing on.
Even could be damp in an outside lamp fixing .. or a nail/tack skinned a cable in wall somewhere!

[The Builder]

Good point. Outside lamps are often the problem.

I'm really intrigued about having to go "outside" to operate a switch. Do you mean outside in the rain, or in a lobby outside your flat/house?

(An RCD is a Residual Current Device. It detects only leakage to earth (for your safety). It doesn't detect overload or short circuit. Your fuses/circuit breakers do that.)

Can you describe the switch?

[AlBags]

Maybe they have one of those outside boxes in the wall.
I can't see it can be difficult at least finding the bad circuit.
Once you find the circuit, you can disconnect loads on it .. or disconnect outside or unknown wiring to test.
Logic and patience .. all that is needed.

[BRIGHT SPARK]

You have a distribution board that was fitted between 1980 and 2000 ish.It has a.30ma rcd fitted as a main switch.These trip at around 25ma.You should test each appliance in turn to determine the culprit.

[BRIGHT SPARK]

Just read about the external switch....you may have a voltage operated trip next to the service head.Determine the fault ...save some cash then have the system updated to 17th edition.Are you or were you on an overhead supply i.e.TT

[BRIGHT SPARK]

Me again.......come on AL the speed must be going to your head...if it were a circuit fault then the trip would not reset.....its an intermittent appliance fault....my bet the iron

[AlBags]

I agree mate ... but I 'have' seen damp cause intermittent tripping before.
But likely it's a permanently plugged in/connected load/motor/element, etc, etc.

[Old_Geezer]

ALL circuits have to be RCD protected ? Wow, glad my freezer isn't. Don't want something minor tripping the lot when I'm on holiday, allowing me to come home to a freezer full of garbage.

[Maydup]

Give up ironing - that's the answer to a happy life.