Why does my RCD keep tripping?

[neil100]

Hi,

I hope someone with some electrical know how can help me troubleshoot a problem!

I am getting an intermittent tripping of the main RCD in our electric box. It can happen any time
of day or night, and can go for days or weeks without happening. If it had been at consistent times
It might have pointed to a timer or pool pump or something, but it is very intermittent.
It happens whether there are people in the house or not.

How do you go about pinpointing the problem, because I am worried we'll be away for a week
and the freezer will defrost, the pool wont get chlorinated etc!

Many thanks
Neil

 

[Deena]

Sorry cannot give you any technical details. When mine has tripped before, it was a process of elimination, painful as it was. Mine was my fridge, the last thing I tested and the least I expected it to be.

Good luck in pinpointing the problem.

 

[Rixter]

Sorry cannot give you any technical details. When mine has tripped before, it was a process of elimination, painful as it was. Mine was my fridge, the last thing I tested and the least I expected it to be.

Good luck in pinpointing the problem.

Yes Deena is correct. I am a qualified electrician and its a process of elimination. You cant test for a fault when the fault is not there to be tested for. Having said that, by you saying it can happen when you are not in the house suggests its possibly coming from an appliance thats connected 24/7 (such as fridge/ freezer/clock radio/ etc etc)..Those are the areas to start looking first.

 

[Propertunity]

It is usually the fridge or the freezer. Check drip trays, check cockroaches in the back that short out the terminals at the back.

If it it when people are home it is usually, the toaster (burnt bits in the tray at the bottom that no-one cleans out that touch the wires), the iron (water again), or the hair drier.

Just a process of elimiation as the others have said. It could be anything. It can also be people overloading one powerpoint circuit too (but this is normally a winter heater thing).

 

[neil100]

Thanks guys,

Ok, that all makes sense, but is it something I can test, and if so, what do I need to test it?

Thanks
Neil

 

[lizzie]

if it's intermittent, i'd start with the fridge (as others have suggested).

the fridge comes on intermittently to cool even if someone is not home - otherwise it might be another appliance that is on all the time that overheats.

the only way to test (that i know of) is to unplug everything, then plug them back in - one at a time - until something trips the switch, and there is your culprit. i'd have the fridge unplugged for a period so that when plugged back in it automatically goes back into cooling mode.

 

[BV]

Its a difficult one but not impossible to find.
An electrician should be able to check for leakage on all circuits.
It could be an appliance but it could also be the wiring.

Once I had the insulation of 2 wires burned up and there was some leakage but not enough to trip the RCD.
This changed every time there was moisture in the air and it would trip the RCD .

With all appliances disconnected, if the electrician finds no leakage at all then it could also be the RCD itself. Some electricians would have testing devices for RCD's but not everyone has so if you get someone over and he can't find the problem then ask him to replace the RCD anyway.
It could save you another service call.