RCD Trips when lights switch off

Hi All

Just a quick one,got a problem I have never come across before. When I switch off a recently wired outside light the RCD trips, it doesn't happen when you switch it on only when you turn it off. There is no water ingress and no sign of tracking (these would surely both cause RCD to trip when turned on). Any help would be greatly appreciated

Thanks in anticipation

Hi AllJust a quick one,got a problem I have never come across before. When I switch off a recently wired outside light the RCD trips, it doesn't happen when you switch it on only when you turn it off. There is no water ingress and no sign of tracking (these would surely both cause RCD to trip when turned on). Any help would be greatly appreciated

Thanks in anticipation

Click to expand...

It would trip when switch off if some plonker had stuck the earth wire into the unused half of a 2-way switch?

Can you reset the RCD while the switch is OFF?

i.e

is the fault during the instant of switch off

OR

permanent while the switch in the off position?

:| :innocent

Is the switch double pole?

Have had problem with double pole switched sockets tripping when switching OFF.

Is the switch double pole?Have had problem with double pole switched sockets tripping when switching OFF.

Click to expand...

You are thinking around the blue sky, envelope, outside the box there timmyspark....

You obviously need more...

GuinnessGuinnessGuinnessGuinnessGuinness

at this time of night!

Spose could be switched fuse spur with neon and something lose inside?

You are thinking around the blue sky, envelope, outside the box there timmyspark....You obviously need more...

GuinnessGuinnessGuinnessGuinnessGuinness

at this time of night!

Spose could be switched fuse spur with neon and something lose inside?

Click to expand...

Straight up

Do a bit of research and you will find its a known cause

See link :

http://www.rolec.net/images/downloads/understanding_rcds.pdf

Item 12 is interesting Trailer boy

See link :http://www.rolec.net/images/downloads/understanding_rcds.pdf

Item 12 is interesting Trailer boy

Click to expand...

:Applaud

Nice little article that.



BTW I wasn't questioning the concept of D/P switching causing RCD to trip...

Just the fact that my brain was on a single pole light switch train of thougth...

in between Speckled Hens!

GuinnessGuinnessGuinnessGuinness

Thanks for all suggestions,

Firstly its a one way switch wired three plate

Secondly the earths are all nice and tight in their terminal

Thirdly the RCD can be reset with the light switched on or off

All wiring was new last year and tested (results were ok)

All connections have been checked and tightened and nothing untoward has been found

Losing whats left of my hair

bad day explode

do yourself a favour and disconnect the connections at the fitting. Then try the switch, if the RCD doesnt trip then its an internal problem of the fitting - simples....

Have you tried a half test on the RCD ?