Hello from new member. Help needed on Dual RCD

[MHenry]

Hi all. This is my first post. I'm in need of some help. This one has stumped most of the blokes on site. View attachment 32498View attachment 32498
All wiring seems fine. However, when the shower is in use it trips the RCD on the 63A bank on the opposite side. You can see from the pic that the shower is on other bank.
The electrician is adamant there's not a crossed neutral and everything works does work independently. We've isolated the upstairs lighting thinking it was something to do with that but yet it still trips the left RCD.
Has anything ever happened like this to anybody before and if so how was it dealt with. It's puzzling us how something on a different RCD can trip the other and not itself or the mains.

Many thanks in advice.

 

[Marvo]

Welcome to the forum MHenry. Not sure what happened to your photos, for some reason they didn't attach. Maybe have another go at uploading them if you can.

It's almost certainly a crossed neutral, borrowed neutral or some kinda neutral fault causing the tripping.

 

[Pete999]

Hi all. This is my first post. I'm in need of some help. This one has stumped most of the blokes on site. View attachment 32498View attachment 32498
All wiring seems fine. However, when the shower is in use it trips the RCD on the 63A bank on the opposite side. You can see from the pic that the shower is on other bank.
The electrician is adamant there's not a crossed neutral and everything works does work independently. We've isolated the upstairs lighting thinking it was something to do with that but yet it still trips the left RCD.
Has anything ever happened like this to anybody before and if so how was it dealt with. It's puzzling us how something on a different RCD can trip the other and not itself or the mains.

Many thanks in advice.

Can't see any pictures

 

[HandySparks]

Likely to be a neutral to earth fault on a circuit connected to the RCD that's tripping.

 

[Skelly]

Can't see any pictures but your description of the tripping is a crossed Neutral :banghead: