Blooming borrowed neutrals

[aaronstuart]

Had a crap day, replaced a cu in a small terraced house.
No problems until dinner, done all tests with good results, ring main on one side of rcd, and lights on the other rcd ( only 1 x lighting circuit ), and both rcd's were tripping.
Found it was a borrowed a neutral from the ring main ( JB in loft ) feeding the extractor fan!!!!!!

 

[sparkylad]

You have my sympathy mate, we are always being hampered by previous work by the boys in tall hats and spurs----makes you mad doesnt it ?


sparkylad

 

[Guest123]

Idiots!!!

 

[davelerave]

ya-haven't had much trouble with this sort of thing but

- nothing will show across circuits until the load is switched on/in-circuit

- and then either or both rcds can trip

 

[aaronstuart]

Luckily the first time I've come across this..........borrowed neutral on the up/down lights fairly often......just a pain in the rear.....

 

[WB Scott]

IR test across the neutral bars should show it up befor hand. Had this myself, right pain in the back side.