Stair Circuit Tripping RCD

[guest119]

Evening All,

Installed a new dual RCD CU today, all dead tests were ok however once live everythings fine until the landing light's switched on and BOTH RCD's trip, anyone experianced this before, any suggestions anyone ?

Must be some size of house if it has landing lights?

Boydy

 

[Dave W]

Thanks to everyone giving constructive answers for confirming what I thought, just wanted to check I hadn't missed anything blindingly obvious before tracking down the borrowed feed.

 

[kingeri]

Thanks to everyone giving constructive answers for confirming what I thought, just wanted to check I hadn't missed anything blindingly obvious before tracking down the borrowed feed.

Hmmm....kinda came across as though you did, really.......

 

[Zebra Stripe]

Hidly Hi, and Hodily Ho Im with Flanders but not sure why...

"However, the cowboy method of putting both circuits on the same MCB would actually be safer than the current situation.."( DJ OvenGloves 2 hours ago 2014 Electricians forum (Internet))

Would indeed make it 1 circuit (me 2014 Electricians forum (Internet))

 

[kingeri]

If the homeowner won't let you/pay you to hunt down the borrowed/shared neutral, then putting the whole thing on one MCB is really the only option. Not ideal, but that's why we test for such things BEFORE changing the CU so you could bring it to their attention beforehand and include the associated remedials in your quote.

 

[telectrix]

9 times out of 10, you'll find the L for the landing light is jumpered off the hall light switch where you have a 2 gang switch in the hall. the answer is to dis. this feed, feed the upstairs switch from the upstairs circuit,and then run an extra conductor ( or 3 core/E ) between switches. can end up messy if chasing is needed.

 

[kingeri]

In my house all the lighting was originally on one circuit, I now have four lighting circuits, but the landings are still on one circuit! For now at least, I can't justify making the mess to split them. If this circuit did pop then each floor (there are 4 floors) would still have some lighting from the other circuits.