Main fuse tripped

grumbler

I had a laptop power supply that tripped my RCD randomly.

TMSG

@Section62 @grumbler The base and the contacts on the kettle were the first thing I checked when I started to suspect the kettle and they were and are completely dry.

@frugalmacdugal No, if I connect just the base and leave the kettle off it then it hasn't happened (though again, this is not a 100% thing as I'd need a lot more time to make sure there's correlation).

As to replacing the kettle, sure, that's what I'm gonna do once I am sure it's the culprit. However, I still would like to understand the reason for this. Never a day goes by w/o learning something interesting.

Section62

grumbler said:

Section62 said:

TMSG said:

Water getting into the kettle base (or a similar fault) could cause a RCD to trip, even if the kettle isn't being used.

Buying a new kettle (and seeing whether the fault repeats) will probably be cheaper than getting an electrician to investigate.

You don't need an electrician to check the base and dry it if needed. Unplugged, of course.
The only problem can be with security screws (if any), but even without a matching screwdriver  bit they can usually be removed with a right size flat screwdriver

If water has got where it shouldn't once, then there's a chance it will get there again. Or it could be another type of fault with the kettle.

Next time the RCD may not trip as it should.

Also repeated tripping of the power can damage sensitive electronic equipment, and possibly the RCD itself.

Why take the risk(s) for the sake of a (say) £20 kettle?

grumbler

Section62 said:

grumbler said:

Section62 said:

TMSG said:

Water getting into the kettle base (or a similar fault) could cause a RCD to trip, even if the kettle isn't being used.

Buying a new kettle (and seeing whether the fault repeats) will probably be cheaper than getting an electrician to investigate.

You don't need an electrician to check the base and dry it if needed. Unplugged, of course.
The only problem can be with security screws (if any), but even without a matching screwdriver  bit they can usually be removed with a right size flat screwdriver

Why take the risk(s) for the sake of a (say) £20 kettle?

Not everything can be measured in pounds.

TMSG

One practical reason why I'd like to get some idea about why and how this happens is that I am often away for a couple of weeks, sometimes longer... and if the RCD trips while I am away, the contents of the freezer will be in an interesting state when I return. I am not keen to experience this

Section62

TMSG said:

Section62 grumbler The base and the contacts on the kettle were the first thing I checked when I started to suspect the kettle and they were and are completely dry.

The amount of moisture needed to create a leakage path won't necessarily be visible to the eye. (assuming moisture is the issue here)

TMSG said:

One practical reason why I'd like to get some idea about why and how this happens is that I am often away for a couple of weeks, sometimes longer... and if the RCD trips while I am away, the contents of the freezer will be in an interesting state when I return. I am not keen to experience this

This is why I always unplug and/or isolate everything which isn't essential before going away.  If it isn't needed then unplug.  If it can't be unplugged then isolate at the most convenient double pole switch.

If the contents of the freezer make it worthwhile, consider getting the freezer powered from a separate circuit protected by its own RCBO.

Section62

grumbler said:

Section62 said:

grumbler said:

Section62 said:

TMSG said:

Water getting into the kettle base (or a similar fault) could cause a RCD to trip, even if the kettle isn't being used.

Buying a new kettle (and seeing whether the fault repeats) will probably be cheaper than getting an electrician to investigate.

You don't need an electrician to check the base and dry it if needed. Unplugged, of course.
The only problem can be with security screws (if any), but even without a matching screwdriver  bit they can usually be removed with a right size flat screwdriver

Why take the risk(s) for the sake of a (say) £20 kettle?

Not everything can be measured in pounds.

E.g. "Health" and "Life".

GDB2222

TMSG said:

One practical reason why I'd like to get some idea about why and how this happens is that I am often away for a couple of weeks, sometimes longer... and if the RCD trips while I am away, the contents of the freezer will be in an interesting state when I return. I am not keen to experience this

It takes barely any residual current to trip the RCD. 30mA on most RCDs. So, a tiny trace of water can cause that. 

I suggest that you disconnect whatever kettle you have before leaving for two weeks.

TMSG

Section62 said:

This is why I always unplug and/or isolate everything which isn't essential before going away.  If it isn't needed then unplug.  If it can't be unplugged then isolate at the most convenient double pole switch.

I normally unplug everything that's "expensive" ie TVs, computers, stereo etc plus the router and its connection to the phone line. I'm now 24 years at this property and I have never had a tripped RCD... so until now I have lived in a state of blissful ignorance

@GDB2222 After that, I will disconnect everything that's not absolutely required!

Section62

TMSG said:

Section62 said:

This is why I always unplug and/or isolate everything which isn't essential before going away.  If it isn't needed then unplug.  If it can't be unplugged then isolate at the most convenient double pole switch.

I normally unplug everything that's "expensive" ie TVs, computers, stereo etc plus the router and its connection to the phone line. I'm now 24 years at this property and I have never had a tripped RCD... so until now I have lived in a state of blissful ignorance

Usually it is the cheap stuff you have to worry most about.

Also anything involving water - kettles, coffee makers, immersion heaters, dishwashers, washing machines.  A significant cause of RCD tripping is when heating elements fail and allow water to create a leakage path.  Things like corrosion (a cause of element failure) can continue whether or not the appliance is being used.