RCD trips

[teknojon]

Hi - bit confused. Left consumer unit on but lighting (a flat, so only 1 lighting circuit) breaker off (due to other trades needing power tools), I was replacing a light fitting and cut the neutral wire only (not the whole cable) and it tripped the RCD? Any thoughts on that? I only cut an inch off the end of the neutral - I'd understand if i'd cut neutral and cpc together...

 

[telectrix]

suggest you caught the cpc as well without noticing. done it myself a few times.

 

[teknojon]

thanks for your reply telectrix - was pretty sure i only cut the neutral tho...

 

[telectrix]

captain smith was sure the titanic was unsinkable......

 

[teknojon]

the sheathing was stripped back leaving live, neutral and cpc exposed. the only short could be if i'd touched the cpc copper with the pliers as i cut the neutral. I may well have done this, but was wondering if it could possible be anything else?

 

[telectrix]

that's the most lkely. as i said, done it myself a few times. that rascally bare cpc flops about all over the place and usually touches your cutters juat as you snip the neutral.

 

[teknojon]

thanks fella

 

[mechelec]

was you touching the exposed metal on the sidecutters when you cut the neutral. that will operate the RCD if you are earthed

 

[teknojon]

hi mechelec - I've thought of that - i may have touched, i was quite careful tho. i was simply wondering if there could be any other reason...

 

[pushrod]

Think that i have caused an rcd to trip by just touching the neutral with my finger in very similar circumstances to what you described in your first post, whilst standing on a step ladder with large rubber feet. (don't think that there were other contacts)

 

[teknojon]

ah - pushrod you too...
It was a bit embarrassing because i couldn't explain to the client why it had happened - he was holding the light for me at the time. i'd just finished explaining why the rcd trips when cutting thru the whole cable.

 

[pushrod]

ah - pushrod you too...
It was a bit embarrassing because i couldn't explain to the client why it had happened - he was holding the light for me at the time. i'd just finished explaining why the rcd trips when cutting thru the whole cable.

When it happened to me there were other appliances on in the kitchen and i just blabbered on about the cumulative effects of small earth leakages from other appliances and went and detached the neutral as well at the CU. Must admit i didn't really have much of a clue as to what had happened, but didn't let on

 

[teknojon]

ha ha... i've got to swot up on instant bull for these moments!!