OK - I've now read a lot on this forum about RCD nuisance tripping, some fantastic responses (so here's hoping!)
Here goes:
10 year old house, new extension last year, single RCD board (not a split board), lots of new wiring (distribution box moved etc), new boiler and valve heads (not new pump though) no problems all fine (finished last July). RCD never ever tripped except when a filament bulb blows.
But ... had outside wiring for lights fitted two weeks ago (wiring was in but not connected) and from the minute the guys tested the circuits it started tripping all the time.
So ...
Found that the RCD was "sensitive", the boiler firing would trip it every time and it tripped on 1/2 current during tests so changed the RCD. It's a 30ms type.
Still tripped randomly day and night (1-2 times a day).
New circuit tested fine though (no earth leaks etc).
Disconneted whole new outside circuit (L, N and E) from ring - still trips ... mmm, now what?
2 days ago unplugged all I could and it hasn't tripped since (freezer, boiler, fridge still on though) although this might not be long enough to prove anything.
And therefore ...
I've look at what the guys did and it looks top class (I used to be an electronics engineer so sort of know what I'm looking at).
So I concluded either: 1) the sparks disturbed something (looked closely around where they worked, pretty simple installation, no cable nicks/nails etc.) or 2) their testing fried something it shouldn't.
Could number 2 actually happen? Computers were plugged in but not switched on when they ran the tests (everything works OK though).
Any ideas?
Here goes:
10 year old house, new extension last year, single RCD board (not a split board), lots of new wiring (distribution box moved etc), new boiler and valve heads (not new pump though) no problems all fine (finished last July). RCD never ever tripped except when a filament bulb blows.
But ... had outside wiring for lights fitted two weeks ago (wiring was in but not connected) and from the minute the guys tested the circuits it started tripping all the time.
So ...
Found that the RCD was "sensitive", the boiler firing would trip it every time and it tripped on 1/2 current during tests so changed the RCD. It's a 30ms type.
Still tripped randomly day and night (1-2 times a day).
New circuit tested fine though (no earth leaks etc).
Disconneted whole new outside circuit (L, N and E) from ring - still trips ... mmm, now what?
2 days ago unplugged all I could and it hasn't tripped since (freezer, boiler, fridge still on though) although this might not be long enough to prove anything.
And therefore ...
I've look at what the guys did and it looks top class (I used to be an electronics engineer so sort of know what I'm looking at).
So I concluded either: 1) the sparks disturbed something (looked closely around where they worked, pretty simple installation, no cable nicks/nails etc.) or 2) their testing fried something it shouldn't.
Could number 2 actually happen? Computers were plugged in but not switched on when they ran the tests (everything works OK though).
Any ideas?
