RCCB tripping when changing socket with power off?

[coolhands]

I switched the MCB off to change the cooker socket to a new one after decorating. I checked power was off with fluke tester shown in pic. During the process the RCCB tripped. I cannot fathom why if the power was off. I was pondering it while working, and thinking about the odds of it happening coincidentally since it has never tripped before.

I completed the task and everything seemed to work ok. Afterwards I was changing the FCU next to it. Again I switched MCB and checked power was off, and changed the FCU. Again during the process the RCCB tripped.

So, is this normal? Acceptable? Anything I need to get checked or I can check? (have multimeter!). The circuits shown were part of a kitchen extension a few years ago.

thanks

*edit* don't worry just read it's the neutral touching the earth

cheers!

https://lh3.googleusercontent.com/-...AAAAAAG4Y/hmUP9DpYNVg/s1000-Ic42/DSC_5691.jpg

https://lh3.googleusercontent.com/-...AAAAAAG4c/py5eOZjx06M/s1200-Ic42/DSC_5693.jpg

 

[DrJimFranklin]

You killed the electrical supply...but the Neutral and the earth are still connected. You must have touched the earth and neutral, or touched the bare copper of the neutral with your fingers or something which earthed it out.

The toroid measuring the voltage on the conductors (phase and neutral) would instantly see an imbalance and trip the unit.

 

[coolhands]

cheers

(goes off to google 'toroid'...)

 

[DrJimFranklin]

cheers

(goes off to google 'toroid'...)

Try this


http://www.explainthatstuff.com/howrcdswork.html

 

[Adam_151]

As a side point you need a blank for that spare way in your consumer unit.

The other blanks fitted are Merlin Gerin and its probably a poor fit and has fallen out on the floor?. Thats an old style Siemens board (same design as old style MK) and I think you would stuggle to get the right blanks these days unless second hand on ebay. I'd probably try Hager blanks (the full ones that look like a dummy MCB- JK01 I think?)

 

[JohnW2]

The toroid measuring the voltage on the conductors ....

I presume that you know what you mean, and I think I know what you mean, but it is not a good idea in a DIY forum to talk about such nonsense as "a toroid measuring voltage", since that will merely confuse those who don't already understand how an RCD works.

Kind Regards, John

 

[bernardgreen]

Neutral_Earth_trip

• bernardgreen
• 16 Jan 2011
• 48

 

[ban-all-sheds]

Do you own a McIntosh 275 or lust after one?

 

[coolhands]

haha no I just like the picture and was looking for something suitably electric as my avatar.